Shutting off the gas and water to a failed water heater should be done with safety in mind. Here are the safest steps, in the proper sequence, to accomplish this:
Safety is of utmost importance when dealing with gas appliances and water heaters. If you are unsure about any of these steps or have concerns about gas safety, it is best to contact a qualified professional to handle the situation and address any potential issues with your water heater.
Installing a gas water heater as a DIY homeowner can be risky if not done correctly. Some of the highest risk aspects associated with DIY installation of a gas water heater include:
To minimize these risks, it’s always advisable to hire a professional licensed plumber to handle the installation of a water heater. They have the expertise, tools, and knowledge to ensure that the installation is safe, code-compliant, and free from the risks associated with DIY installation. Additionally, professional installation often comes with warranties and peace of mind.
A new water heater can potentially cause smelly water and a rotten egg smell in the hot water if there is an issue with the water quality of the water source.
Here are some reasons why you may experience a rotten egg smell in your hot water, especially after the installation of a new water heater:
It’s important to note that these issues can also happen in older water heaters as well, and not only in new ones. To address this problem, you should have a licensed professional inspect the installation, complete a water quality test, check for the presence of sulfur bacteria or high levels of sulfates, and test the water source. They will also check the anode rod and the plumbing. Based on their findings, they will recommend the necessary steps to eliminate the smell and prevent it from reoccurring.
NOTE: Water quality is a fluid and dynamic state that changes continually. As water quality changes, the needed solutions must also change and adapt if perfect water quality is desired.
When well water is present and/or iron-eating bacteria is present, an aluminum anode rod is typically considered to be a better option than a magnesium anode rod.
Here’s why an aluminum anode rod is considered to be a better option for homes with well water:
It’s important to note that even though aluminum anode rods are more resistant to corrosion in well water and water with iron-eating bacteria, it’s still important to regularly check and replace them to ensure that the water heater tank is protected. Additionally, you should consult with a plumber or water treatment professional to determine the best course of action for your specific well water or iron-eating bacteria situation.
Magnesium and aluminum anode rods are both used in water heaters as a means of protecting the tank from corrosion. However, they have some important differences as explained here.
Here are some important differences to consider regarding magnesium and aluminum anode rods in your water heater:
In summary, the main difference between magnesium and aluminum anode rods is that magnesium anode rods are more efficient in soft water and have a shorter lifespan, while aluminum anode rods are more efficient in hard water and have a longer lifespan. The choice of which one to use depends on the water hardness of the area and the budget.
When you have well water, your water heater and other water appliances require extra care to ensure that they function properly and last as long as possible.
Here are a few key things for owners of homes with well water to keep in mind:
By following these best practices, you can help to ensure that your water heater and other appliances are in good working order and that they last as long as possible. More importantly, you can ensure your family has safe healthy water for all your needs.
While rare, residential water heater explosions do occur and can be deadly. Explosions are possible with both gas and electric tank water heaters, primarily those that are poorly maintained. You can avoid such a catastrophe when you identify the signs a water heater might explode so you can call for plumbing service immediately.
High internal temperatures and pressure can contribute to a water heater explosion. Units are equipped with safety mechanisms to prevent levels from becoming excessive, but when malfunctions occur, an explosion may result.
When the water heater’s temperature is set too high, thermal expansion of water increases pressure inside the tank to extreme levels. Sediment gathered in the bottom of the tank insulates, which can increase temperatures beyond a safe level. Rust and corrosion of metal components prevent proper performance and impedes pressure regulation. Other component defects can cause increased temperatures and resulting high pressure.
Typically, the system’s temperature and pressure relief valve allow excess pressure to escape the tank – if this component malfunctions, pressure continues to accumulate until the tank can no longer hold.
Gas leaks also create the potential for a hot water heater explosion and the risk of a fire.
When temperature and pressure rise too high, the system produces some warning signs. If you detect any of the following signs your water heater is going to explode, call for emergency plumbing repair service.
The T&P valve regulates temperature and pressure inside the hot water heater tank. When this valve leaks, it’s a sign the component cannot handle internal tank pressure. Defects with the T&P valve are a leading cause of water heater explosions.
When performing as designed, the T&P valve opens when internal pressure reaches a specific set point to relieve thermal expansion which lowers pressure. The valve also opens when water temperatures reach a high set point, allowing cool water to enter that tank and mix to reduce water temperatures. In either scenario, the valve closes once problematic conditions are relieved.
If the T&P valve always remains open, this indicates consistent issues with internal pressure and water temperature. which could cause an explosion should the valve fail.
When tanks are not maintained and flushing is not performed on a regular basis, sediment from the water supply gathers at the bottom of the water heater. Thick layers of sediment effectively become insulation between the water and heating elements, and temperatures increase because the heating elements are unable to efficiently heat the water supply. Popping occurs as water trapped below the sediment against the heating element boils.
A popping sound indicates the presence of sediment and the potential for overheating due to the conditions explained above. Sediment also poses a risk of T&P valve malfunction, as the sediment can clog this component and prevent it from opening when needed to relieve high pressure and temperature conditions, creating issues that are signs your water heater might explode.
Brown water is another sign your water heater may explode as it indicates the presence of sediment in the tank. Hot water from household taps may also present a brown color when rust is present, meaning components of the water heater or the tank have rusted and are at risk for malfunction. Sediment and its indicators are signs a hot water heater might explode.
The smell of rotten eggs near your water heater is another sign your water heater could burst as it indicates a gas leak. Gas leaks occur due to poor installation, damaged gas lines and other system issues. The water heater’s pilot light can ignite the gas, leading to a severe explosion and fire.
A water heater explosion can be devastating. This extreme system failure can cause extensive damage to the home and its plumbing system, and the force of an exploding hot water heater tank has the potential to injure or kill occupants. Diligently watch for signs your water heater might explode, and contact your plumber immediately for emergency plumbing repairs.
Original post: https://grovehvac.com/signs-your-water-heater-is-going-to-explode/
A leaking water heater is quite bothersome – It can give off a pretty dangerous vibe and may make taking a shower to appear to be unsafe.
It is perfectly safe to shower when the water heater is leaking. However, in order to prevent further water damage, it is important to figure out what is causing the water leak.
To help you out, we’ve compiled all the information you need to know regarding water heaters – Why they malfunction, what you can do to address such issues, how long they last on average, and much more! Keep reading to find out everything you need to know regarding why a water heater could possibly leak.
There are a number of reasons why water heaters could start leaking, figuring out the exact reason usually requires a close-up inspection.
The most common cause for a leaking water heater is the drain valve, however, there could be a number of other reasons why it has sprung a leak. We’ll take you through the primary reasons as to why water heaters start leaking;
Typically, water heaters have supply lines that are installed to ensure a smooth flow of water into the tank of the water heater. A leak in this part of the setup is most often the culprit and can leak all the way down to the wiring and/or the tank itself. When this happens, it can look like there is an issue with the tank or other parts of the water heater. If the supply tubes are, in fact, faulty, your only option is to replace them. To do so, you can enlist a professional or purchase replacement tubes and swap them out.
Where the water lines connect to the water heater, you’ll find a set of fittings. This is another area in which leaks can be very common. In most cases tightening the fittings slightly solves the problem. Be careful however if you have brass compression fittings. It is very easy to overtighten them. Most brass compression fittings should be hand tightened and then a further quarter turn.
Typically, Temperature and Pressure (T&P) Valves can cause leakage in your unit. That being said, this usually indicates a more serious issue and in most cases, it is advisable to call a plumber.
Most water heaters have a drain in the lowest part of the unit. Depending on the type of valve used the rubber seals in the valve can deteriorate and the valve itself can start leaking. In most cases when the valve is leaking it is necessary to replace the valve. This is doable as a DIY project. Just make sure to buy the right size valve. Here is a 3/4 inch valve with a 2-inch shank from Amazon.
If none of the previous solutions seem to work, odds are your water heater’s tank is leaking. This typically happens when there is a hole in the tank, this can be due to rust or manufacturing defect.
The answer to this question largely depends on the nature and scope of the leak itself.
If the heater is leaking from a fitting or a drain valve theoretically this has no effect on the longevity of the heater and you could use the heater like this for years.
Provided of course that you don’t mind the water damage
However, if it is a more serious issue, such as a leak within the tank the leak will only increase over time and the unit should be replaced as soon as possible.
When choosing a new water heater and you live in an area where there are frequent power outages you might be interested in finding out which type of water heater is best for that.
I have written an article about showering during a power outage, go check it out, there is a ton of info in there about water heaters.
If you find out that it is necessary to replace the water heater it is a good idea to consider tankless water heaters. They have many benefits over traditional water heaters.
Here are 9 benefits of a tankless water heater.
While leaks demand immediate attention, performing routine checkups and maintenance can help add longevity to your water heater unit. To get the best results and keep your unit functioning properly, follow these steps to ensure smooth operation;
Many people set their water heater temperature too high. This can shorten the life of the heating element. To prevent that, set your thermostat to a lower temperature (we recommend anything lower than 120 F). This will prevent scalding and protect the taps from hot water.
At least once a year, make sure to drain and flush your water heater’s tank. This will clean the insides of the unit and prevent the build-up of impurities and sediments. To do so, turn off the water supply to the heater and connect a pipe or a hose to the drain valve. Then, put the other end of that pipe into a drain and empty the tank.
When you perform a routine check-up, inspect the external of the heater for small leaks. This will help catch the leak before water damage occurs.
Many people have not considered this, but it is possible to paint a water heater to make it look like new. If yours is still in working order, but you would like to spruce it up by giving it a new coat of paint read my guide on how to paint a water heater.
So, there you have it – this article offers a comprehensive list of ideas and solutions that can help with the maintenance, as well as the service of your water heater. If you’ve exhausted these options, you’ll likely need to install a new unit or call in a professional to help with your current one. Thanks for reading and we hope we have been able to assist you with your leaking water heater!
Original post: https://hvac-buzz.com/leaking-water-heater-shower/
Winter is in full swing and that means, in some areas in the United States, temperatures are dropping as low as 16 below zero. If you live an area that’s getting cold outside, the last thing you want is for your hot water to be getting icy as well. That’s why it’s important that you pay attention to key signs regarding the health of your hot water heater.
Having a dysfunctional water heater can lead to a bevy of issues for homeowners. It can mean cold water coming through your pipes, debris getting into your water supply, and a whole lot more.
To help you better see the signs your hot water heater is going out, below, our team has written out some simple identifiers you can rely on.
A good water heater should be capable of supplying you with enough hot water to get you through the day. This includes being able to serve you and your family during showers while washing the dishes, and while doing other hot water necessary activities. If you’re constantly getting stung by cold water in the shower or are noticing that it takes a long time for your water to warm up once it’s running, you’re experiencing one of the primary signs your water heater is going out.
As water heaters get older, they get more leak-prone. Leaks in your hot water heater not only diminish the amount of hot water they can deliver to your home but can also run up your water bill unnecessarily. If you suspect that your water heater may be leaking, call in a water heater professional to service your unit as soon as possible.
Modern water heaters are excellent at efficiently heating water without making a noticeable noise. If you’ve noticed a change in the amount of noise your water heater is making, it could be indicative of a problem that’s forming or one that is already present. The longer you let the issue sit, the more severe and costly it may be to fix it. If you’re hearing loud noises coming from your unit, consider shutting it off and scheduling a repair immediately.
Heaters that are well past their prime may start to get rusted inside. This rust can then find its way into your water supply. Rust can be dangerous when found in water, especially if you consume water from your home’s tap. Again, a repair professional can help advise on how to best remedy rust coming from your heater and will likely point you in the direction of replacement units worth investing in.
One of the simplest signs your hot water heater is going out that you can easily identify is your unit’s age. If you look at your hot water heater’s manufacturer sticker and notice that it’s over 10 years old, you’ll probably want to get your heater looked at. To extend your water heater’s age, consider hiring a professional to flush your unit on an annual basis.
Now that you know the signs your hot water heater is going out, it’s time to do something about it. We recommend contacting our Long Island-based team at Order A Plumber. Order A Plumber has been servicing homeowner’s water heater and other plumbing needs for years. Let us provide you with the same exceptional value.
Original Post: https://www.orderaplumber.com/blog/2019/january/it-s-getting-cold-5-signs-your-hot-water-heater-/
The water heater may be the most overworked and under-appreciated piece of mechanical equipment in a house. We usually assume it’s doing its job as it should and leave it alone, unless it starts to makes weird and scary noises.
To help you avoid a potentially dangerous and expensive plumbing crisis, we’re looking at four frightening sounds your water heater can make and what they mean.
Original post: https://www.mrplumberatlanta.com/help-guides/four-scary-noises-water-heater-making-might-mean/
Catalog of causes & cures of noises heard at or in water heaters, calorifiers, cylinders:
This article explains how to diagnose and cure noisy water heaters such as popping, hissing, crackling or banging.
We describe the different types of sounds heard at a water heater, what they mean, their cause, and their elimination.
We discuss: How to diagnose and cure water heater rumbling, clanking, cracking, resonant shrieking or whistling, or other hot water heater noises. Advice and photo-guide to de-liming and de-scaling hot water heaters - Scale formation in water heaters and methods of prevention. How to remove silt or debris from the hot water heater tank. Rate of deposition of lime and scale in plumbing systems.
The sketch at page top is courtesy of Carson Dunlop Associates, a Toronto home inspection & home inspection education company. Used with permission.
We also provide an ARTICLE INDEX for this topic, or you can try the page top or bottom SEARCH BOX as a quick way to find information you need.
Here, listed alphabetically, we describe all of the sounds that might come from a water heater, geyser, cylinder, or calorifier.
We give an index into this water heater sound dictionary but you may want to read through the whole list because what one person describes as a hiss another may consider a sizzle. Is it a snap, crackle or pop?
[Click to enlarge any image]
Watch out: don't even think of trying to fix this noise yourself. Making a mistake risks fatal carbon monoxide poisoning. Consult Bosch customer service if you are having noise problems with your tankless water heater.
Other shrieking screaming sounds in and around buildings are discussed at WATER SUPPLY PIPE WHISTLE NOISE
and also
at SCREAMING or whistling or shrieking A/C compressor/condenser unit sounds - warning about high pitched sound from the compressor/condenser unit
Also see GUIAS PARA EQUIPMIENTO EN MEXICO
The hard water mineral deposits tend to collect as a hard skin on the bottom of the heater, interfering with heat transfer, increasing operating cost, and over longer periods, possibly weakening the bottom of the water heater itself.
Mineral deposits also accumulate on the electrodes of an electric water heater, eventually leading to the failure of the heating electrode. If you never remove the scale from a water heater tank the clanking or cracking noise heard at the water heater during operation may eventually cease when the scale solidifies, no longer trapping hot water and interfering with its movement upwards in the water tank.
However the development of a thick lime or scale layer in the bottom of a water heater also reduces the water heater tank life.
Other Water Heater Problems Caused by Hard Water & Scale Deposits are discussed just below.
Our photo (left) shows chunks of water heater scale on the ground after removal from the water heater.
A.O. Smith gives six reasons (here we expand and add to them) for water heater tank scale removal, and the company points out that the reasons for scale removal and indeed the procedure for scale removal is (almost) the same regardless of the energy source: electric, gas, oil, solar water heaters.
Our "exception" is that solar water heaters and electric water heaters may have specific internal components (such as electric water heater electrodes) that will also need to be de-scaled or even replaced. [1]
Noisy water heater operation: Water heater noises, as we described above, may be the first thing people notice when the water tank scale layer has become thick enough to interfere with good water heater operation.
But A.O. Smith and other water heater manufacturers cite additional reasons why removing water heater scale is important.
Clean the water heater tank to reduce water heater noise.
Longer water heater "on" time & slower water heat-up rate: you can reduce the cost of making hot water with your oil, gas, or electric-fired water heater by removing scale from the tank bottom.
The scale layer on the tank bottom (or on an electric water heater's electrodes) interferes with heat transfer into the hot water.
This means that the water heater will have to operate longer (and you will spend more on hot water costs) than necessary to re-heat incoming water.
Clean your water heater tank to reduce your water heating cost by improving heat transfer into the water and correspondingly shortening the water heater "on" cycle time.
High water heater costs to operate, repair, replace: for the same reasons as above: running the water heater longer just to get the water hot enough means higher water heater operating expense.
In addition to higher energy costs to heat the water, unnecessary heater replacement, and in the case of electric water heaters, early failure of the heating elements are common results of heavy scale problems.
Hot water quantity has diminished - not enough hot water: by slowing heat transfer into the hot water in the water tank, the apparent hot water quantity will also be reduced, because incoming cold water is not heated as rapidly when occupants are drawing hot water out of the tank.
Thus the incoming cold more quickly dilutes and cools the hot water that remains in the tank during use. Clean the water heater tank to increase hot water quantity.
Extend the water heater life: because scale on the water heater tank bottom insulates the tank bottom from the water inside the tank, the bottom of an oil or gas fired water heater will become hotter as the scale layer gets thicker.
These increased temperatures weaken the water heater tank bottom and shorten the life of the water heater. Similarly, scale deposits on the electrodes in an electric hot water heater shorten the life of the electrodes. Clean the hot water tank regularly to extend its life.
Protect water heater warranty: if a water heater tank fails the manufacturer may not honor the water heater's warranty if the failure is due to the accumulation of excessive scale inside of the water heater tank.
Water heater warranties typically indicate that the tank is warranted against leaks due to rust, corrosion, or chemical action of the water but the warranty will exclude a tank failure due to scale.
User dissatisfaction with the water heater because of less hot water, slower hot water recovery, and higher hot water costs lead to unhappy building occupants who may have no idea that a water heater scale problem is the cause. If dissatisfaction leads a consumer to replace a water heater that could have just been de-scaled, there may also be unnecessary heater replacement expense.
When the lime thickness reaches the hot water tank drain, there will be about one inch of mineral deposit on the tank bottom. If the water tank has a cleanout opening, when the lime thickness reaches that opening the mineral deposit thickness will be about 2". When you have observed the length of time required for lime to accumulate in your water heater you can set the appropriate maintenance schedule.
See WATER HEATER SCALE DE-LIMING PROCEDURE for a detailed water heater de-liming procedure. A summary of the de-scaling procedure is just below.
The first step in curing water heater noises or poor hot water quantity is to turn off and flush out the water heater.
See WATER HEATER FLUSH PROCEDURE for the full article on the detailed procedure for flushing out water heaters to remove scale, dirt, or debris - a step that can increase hot water quantity, temperature, and water heater life.
Watch out: don't tackle this water heater cleanout project on a Sunday night when you can't call a plumber or buy a replacement part. Water heaters, their heating source (oil or gas burner or electricity or solar hot water), and particularly their relief valves include critical safety components.
Do not modify or remove relief valves, chimney connections, draft hoods, etc. as you may create dangerous conditions. Turn off all electrical and or gas power to the water heater and let it cool.
This means turning off electricity that controls the water heater oil burner or electric heating elements, or for gas fired water heaters, turning off the gas supply to the device.
Additional tips on draining a water heater tank can be found
The second step in curing water heater noise or insufficient hot water is to remove scale or lime from the water heater tank. If the unit is an electric water heater, you'll also need to remove scale from the electric water heater elements.
See WATER HEATER SCALE DE-LIMING PROCEDURE for the full article on the detailed procedure for removing lime and water heater scale.
Safety Warning: never turn on a water heater's heat source before the hot water tank has been re-filled. Otherwise you may damage the heater or create a dangerous condition.
Be sure the water heater pressure and temperature relief valve is properly installed and is the proper type.
See RELIEF VALVES - TP VALVES.
The third step in stopping water heater noises, extending water heater life and increasing the amount of hot water that the heater produces, is to prevent un-wanted scale or lime deposits in the water heater tank or on an electric water heater's electrodes.
The rate of deposition of scale inside of a water heater tank depends on
At WATER HEATER SCALE PREVENTION we discuss in detail and provide research on the factors determining the rate at which scale and lime form in water heaters or on water heater electrodes.
BLEVEs or boiling liquid expanding vapor explosions are discussed
at BLEVE EXPLOSIONS.
Excerpts are below
Water heater tank explosions are rare thanks to the widespread requirement for and use of pressure and temperature relief safety valves. The photo (left) shows a hole in the roof made when a water heater exploded, becoming a rocket that passed up through the building.
But if the safety valve has been damaged, modified, or even omitted (as we saw on our neighbor's water heater), that condition, combined with overheating can cause a water tank to explode, creating a BLEVE - boiling liquid vapor explosion that releases tremendous force and causing extreme damage to a building.
Because repeated heating of the water tank bottom may combine with other conditions (such as corrosion or excessive heating due to mineral deposits on the tank bottom) to produce a weak water heater tank bottom, that is the part more likely to fail in an overheat and overpressure condition.
A failure at the water tank bottom may explain why a BLEVE can produce a water tank explosion that behaves like a rocket, sending the water tank skyrocketing up through a building.
The articles at this website will answer most questions about diagnosing and curing noisy domestic water heaters and about the procedure to remove mineral deposits, lime, water scale, silicates, sulfates, aluminates, or silt and sand from a water heater tank.
Original post: https://inspectapedia.com/plumbing/Water_Heater_Noises.php
Background
Over the course of our nearly three years in business, we have been monitoring the news and our service calls to share some common water heater issues and solutions.
Case #1 | November 2018: Police responded to reports of gunfire in a North Carolina high school. As police performed a sweep of the property, they discovered that the sounds were coming from a water heater that had been undergoing repairs.
Case #2 | March 2019 + December 2020, we had a residential customers call with a similar issues.
Let’s take a look into the possible causes of the alarming sounds created in both cases: In Case #1, it is highly likely that the malfunctioning water heater backfired to create such a loud noise.
What Causes a Water Heater to Backfire?
Sediment Build-up | Sediment is any type of solid material that remains inside of your tank. Water heaters may have sediment build-up as a result of the type of water that is being sourced into your home or business. For example, the water in the City of Chicago comes from Lake Michigan, while the water in some Chicago suburbs and smaller cities/towns tends to come from well water. Although each water supply is different, someone whose home or business runs off of well water is more likely to experience a sediment build-up due to the mineral content. Some examples of sediment-causing elements include lime, iron, calcium and magnesium. The sediment builds up at the bottom of the tank. This can clog the water heater’s drain as well as cause leaks. If the sediment continues to build, it can also contribute to erosion. It is also possible for the sediment to make loud noises when the water beneath the sediment struggles to escape; once it is finally heated to the necessary temperature, the water escapes the sediment and you are likely to hear a loud sound, as in the video below.
January 2021 | Sand sediment drained from customer's unit
Sediment Popping on an A.O. Smith Water Heater
The SOLUTION
Preventative Maintenance: Draining & Flushing the Unit
Our technicians are on the job to service your unit(s) and to educate! Techs often explain and provide little tips and tricks (like draining/flushing) to help ensure that your heater’s full life span is reached. Most manufacturers recommend an annual or bi-annual flush of your unit, depending on your water quality; please refer to your installation manual's maintenance section for additional details.
Note: Depending on your water quality and usage, if your unit is 4+ years old and has never been drained and flushed, a technician may recommend against a flush because longstanding sediment that gets removed may result in erosion and weak spots, causing your heater to leak sooner as opposed to extending its life.
Delayed Ignition: Power Vent Heaters
In some cases, water heaters may have ignition issues that become apparent as a result of the loud popping sounds they cause. In a water heater, repeated failed ignition attempts often mean that the gas has no outlet and remains in the burner chamber. Similar to the explanation of sediment build-up, the gas builds up. If the spark is finally able to ignite and there is excess gas in the chamber, you will hear a loud sound (possibly a gunshot-like sound). Additional causes of delay ignition include, but are not limited to: a dirty blower or blocked gas flow to the pilot burner.
***DELAYED IGNITION IS A VERY DANGEROUS SITUATION***
The SOLUTION
A Diagnose + Repair Service Call
Our technicians are factory trained and certified to repair units experiencing delayed ignition and hundreds of other issues. A technician with a delayed ignition case will first check the ignition, flame rod, and burner chamber; he/she may also check the gas flow and the pilot to determine the cause(s) of the delayed ignition. Please be sure to hire a professional repair service or contact your to ensure that this situation does not escalate.
Venting Issues: Power Vent Heaters
Another larger water heater issue stems from the original installation. If the water heater does not have proper venting, it may be struggling to properly cycle and exert air. A blocked vent may be the cause of a backfiring unit, typically the result of installation error. In some cases, a venting issue can result in the void of your unit’s warranty. Installation specs are listed in the manufacturer’s installation manual, alongside information regarding issues which are not covered by the warranty. | Note: Power Vent heaters are vented with PVC.
The SOLUTION
A Site Inspection + Service Call
Depending on the severity of the issue, you may be asked to submit photos of the installation location in advance so that technicians can pre-assess any potential venting issues prior to arriving on site. During a site inspection, the technician will examine the venting and installation of the unit, which can help determine whether the unit was installed properly. From there, the technician will provide the potential options for repair.
Other Instances of Popping Sounds
In Case #2, we received a call from a Rheem residential customer whose unit required a diagnosis and repair. The customer described hearing a popping sound, which led to our technician replacing the unit’s upper element and thermostat. Elements (see image on the left) typically last the duration of 8 to 10 years. Residential water heaters typically have two elements (an upper and a lower). The elements are responsible to heating the water to the temperature set by the thermostat. Depending on the type of unit you have, the bottom element typically goes on first unless the unit is wired for simultaneous heating. This customer likely heard the element or the breaker popping. Elements may make a popping sound when they are not receiving sufficient airflow and they may be turned off as a result of the culmination of these events causing a circuit to be tripped to the off position.
The SOLUTION
A Diagnose & Repair Service Call
In this case, the customer’s unit required a new element and thermostat, as determined by a technician visiting the site and checking the unit. Although element-based issues are fairly common, technicians will diagnose the unit based on the sounds and issues you report. Then, they will follow-up with the possible repair options.
Original reporting: https://www.uswhpro.com/solved1
Figure 1. Water temperature control is only one part of operating and maintaining plumbing systems to minimize Legionella and an even smaller part of a comprehensive Legionella management plan. This diagram is from the training course Water Temperatures and Legionella in Plumbing Systems. Courtesy of HC Info.
The effect of water temperature on Legionella pneumophila (Lp) found by Sanden et. al. in a laboratory study (Sanden GN, Fields BS, Barbare JM, Feeley JC. 1989. “Viability of Legionella Pneumophila in Chlorinefree Water at Elevated Temperatures.” Current Microbiology 18; 61-65). This diagram is from the training course “Water Temperatures and Legionella in Plumbing Systems.” Courtesy of HC Info.
October 23, 2013
KEYWORDS Legionella / plumbing systems
At first glance, guidelines may lead engineers and facility operators to conclude that controlling Legionella bacteria in plumbing systems can be accomplished long-term by simply raising water heater temperatures.
As with any solution that appears easy and cheap, it is important to check the fine print. For water temperatures and Legionella, the fine print includes the following:
1. Water temperatures are a small part of a big picture.The purpose of managing building water systems to minimize Legionella bacteria is to prevent Legionnaires’ disease. A Legionella management plan must include preventive measures for all water systems that present a significant risk of Legionella growth and transmission, not just for plumbing systems. Minimizing Legionella bacteria within plumbing systems involves much more than water temperatures (see Figure 1 above).
2. Water temperatures may affect Legionella bacteria differently in real plumbing systems than in piping loops set up for laboratory studies.Don’t jump to conclusions based on Figure 2 above.
In an actual hot water system, especially in large buildings, it can be difficult to keep the entire plumbing system at the target temperature even if the water heaters have the capacity to handle periods of highest demand. That can happen because water will cool down in sections where it is stagnant because of the design or infrequent use.
Even where the target temperature can be maintained, Legionella bacteria imbedded in scale or biofilm will not behave as shown in Figure 2. In a pot of water, Legionella will not multiply at temperatures above 50° C (122° F) and will die within about 32 minutes at 60° C (140° F). A large plumbing system is different – it is an entire ecosystem. Every plumbing system has biofilm within a short time after being filled with water.
Therefore, the effectiveness of water temperature management in controlling Legionella cannot be guaranteed and should not be assumed.
3. Regulations limit maximum hot water temperatures.Many government and industry organizations have recommended storing hot water above 60° C (140° F) and delivering it above 50° C (122° F) for Legionella control, including the American Society of Heating, Refrigerating and Air-Conditioning Engineers), the Centers for Disease Control and Prevention, Occupational Safety and Health Administration, (U.K.) Health and Safety Executive, ASTM International and the World Health Organization.
The minimum temperature recommendations present a dilemma because of maximum temperature regulations and scalding risk. For example, the Joint Commission and most state health departments have set maximum temperature guidelines to protect against scalding in hospitals and nursing homes.
The 2009 Veterans Health Administration directive, “Domestic Hot Water Temperature Limits for Legionella Prevention and Scald Control,” plainly states the dilemma: “It is not possible to maintain water temperatures at the outlet that prevent the growth of Legionella and simultaneously eliminate the possibility of scald injury in persons partially or fully insensitive to hot water temperature.”
4. Reducing the cold water temperature may be infeasible or impractical.Most of the same organizations (ASHRAE, ASTM, CDC, HSE, OSHA) that recommend high hot water temperatures also recommend keeping cold water at or below 20° C (68° F).
Water supplied to a building below 20° C (68° F) may pick up heat as it flows in pipes along sun-baked walls, in ceilings, in pipe chases, or because of hot water infiltration at janitor sinks, bedpan washers, shower valves or other cross connections. Some steps to minimize heat gain may be cost effective (e.g., adding insulation; adding check valves to prevent crossover).
However, if the required measures are impractical or infeasible (e.g., relocating pipes), or if the incoming water supply exceeds 20° C (68° F), as is the case in some parts of the U.S., then implementing other control measures (e.g., chemical disinfection) will be more practical than trying to reduce the incoming cold water temperatures.
5. Mixing valves are not a one-size-fits-all solution. Mixing valves can be located just downstream of water heaters to reduce the temperature throughout the rest of the system and at showers and faucets to reduce the temperature just before use.
Setting hot water storage tanks or tank-type heaters at or above 60° C (140° F) is beneficial for Legionella control assuming, based on the tank size relative to hot water demand, water stays in the tanks long enough to be disinfected (Figure 2). Thermostatic mixing valves must be used downstream of the tank outlets to reduce the temperature to a no-scalding level.
If semi-instantaneous heat exchangers are used for water heating, setting them at 60° C (140° F) will be of little or no benefit for Legionella control if water will not be held at that temperature long enough to kill Legionella. Installing a mixing valve downstream of a semi-instantaneous heat exchanger could actually promote rather than hinder Legionella growth by adding surface area (for biofilm development) to the system.
However, mixing valves are typically installed not only (or even primarily) to kill Legionella within water heaters, but to deliver hot water within a more consistent and precise temperature range, which in some buildings could ultimately help with Legionella control.
6. Surprises occur. Delivering hot water within a specified temperature range is about more than water heater settings and mixing valves. It requires a comprehensive plumbing system operation and maintenance program. Target temperatures cannot be assumed because of stagnation, hot-cold crossover and other complexities that can affect temperatures at some outlets, so periodically checking temperatures is important.
Check cold water temperatures at the point of building entry to track the temperature of the incoming water supply at various times of the year. Also, check the temperatures at faucets to identify excessive heat gain between the point of entry and points of use.
Check water heater, hot water storage tank and thermostatic mixing valve gauges to make sure the temperatures are within the target range. Check the hot water return gauges and take readings at outlets to identify excessive temperature loss between the hot water supply and points of use.
The Legionella management plan should outline performance limits for water temperatures. If the limits are not met, investigate the problem and take appropriate corrective measures.
Water temperature management must be given its proper place within a building’s Legionella prevention program — no more and no less. Target temperatures must be set thoughtfully, achieved safely and measured.
As with the entire management plan, the effectiveness of water temperature management in controlling Legionella cannot be guaranteed and must therefore be validated rather than assumed.
Matt Freije is the founder and president of HC Info. He earned an undergraduate degree in mechanical engineering from Purdue University and a graduate certificate in epidemiology and biostatistics from Drexel University. His consulting work has been focused on Legionella since 1995. His first book, “Legionellae Control in Health Care Facilities: A Guide for Minimizing Risk,” has sold in more than 30 countries. Much of this article was excerpted from “Water Temperatures and Legionella in Plumbing Systems,” an e-learning course written and narrated by Freije.
SOURCE: https://www.pmengineer.com/articles/90962-legionella-and-water-temperatures-go-hand-in-hand
Hot water from the home's faucets and sinks can cause serious injury to members of the family. Underestimating the risks posed by burns and scalding wounds only makes members of the household more vulnerable to injury. The following facts about scalds and burns can help illustrate the dangers of improperly heated water in the home.
1. Kids and seniors face the highest risk
Seniors and kids under the age of 5 are especially vulnerable to serious scald injury. A thinner dermis poses an extra threat of deeper burns in children, while limited flexibility can sometimes put seniors in danger with regards to nearby hot water.
2. Overheated water is a common problem at home
Ironically, many homeowners that balk at the idea of burn-related injuries in the home are at the greatest risk. Over 40 percent of inspected urban homes were found to have water heaters set at or above 140 degrees. Setting water temperatures to 120 degrees will increase safety and heating efficiency simultaneously.
3. Serious burns can occur in seconds
Burn wounds caused by a home's water supply can occur quickly. In fact, 140 degree water can cause a third-degree burn after just five seconds of exposure.
4. Cool water is better than ice for temporary treatment
Resist your instinct to ice a serious burn or scald, as treating the injury with ice actually risks worsening the burn. A wet compress or a flow of cool water will do the trick until you can schedule a medical visit.
5. Scalding injuries are mostly preventable
While hundreds of thousands of scald wounds occur each year, 75 percent of burn injuries in children are preventable. Families taking a proactive approach toward preventing burn injuries will see rapid results in the form of fewer burn accidents.
6. Going tankless can eliminate scald injuries
Often performing maintenance on an aging water heater simply increases risks of a scalding accident. Electric tankless water heaters have more precise, reliable heat controls to help prevent burn injuries.
SOURCE: https://webflow.com/design/hot-water-safety
Use caution when dealing with hot water!
Hot water can be dangerous. Adults and children alike can be scalded or become sick with Legionnaires’ disease if your hot water system is not setup properly.
Furthermore, installing hot water systems is dangerous. Improperly installed systems can cause carbon monoxide to enter the home or cause home explosions.
We advise you to have a licensed professional install, tune and maintain all your hot water systems. Doing things wrong could be a life or death situation.
DO NOT TAKE THESE RECOMMENDATIONS LIGHTLY. IGNORING THESE COULD LEAD TO DEATH.
Hot water 154 degrees fahrenheit or warmer will scald you instantaneously. It takes 2 seconds for a first-degree burn with 140 degree fahrenheit water, and 3 minutes for a first-degree burn with 120 degree fahrenheit water. It is critical for you to keep your hot water tap temperature no warmer than 120 degrees.
Temperature
Time for First Degree Burn
Time for Second Degree Burn (Permanent)
110° F
Normal Hot Shower – No Burn
Normal Hot Shower – No Burn
120° F
3 Minutes
9 Minutes
126° F
30 Seconds
90 Seconds
131° F
5 Seconds
25 Seconds
140° F
2 Seconds
5 Seconds
154° F
Instantaneous
1 Second
Source: ASSE-Plumbing.org
Original reporting: https://hotwaterlab.com/hot-water-safety/
They get too hot, the water inside turns to steam. Steam takes up far more room than the water it once was, and the expansion rips the water heater apart. And make no mistake, there have been some spectacular water heater explosions. The MythBusters have addressed (if that’s the right word) this issue several times:
If this happens in your home you probably won’t show the same level of enthusiasm as these fellows, though. Here’s another less, ah, flamboyant link:
Water Heater Explosions – Should You Be Concerned? | Water Heater Hub
Naturally, there are safety devices to prevent this, mainly a thermostat to turn off the heat source (gas or electric) before things get anywhere near too hot. The next safety device is the T&P valve, the temperature and pressure valve, designed to open if the temperature or pressure gets too high. In order to make the video above, the MythBuster guys had to disable the thermostat and remove the T&P valve.
Of course, no homeowner would ever do that, but over time the T&P valve can get stuck, then fail when it is needed. It needs to be tested, maybe about once per year; if it keeps leaking after the test, have it replaced. There’s no end of websites discussing water heaters and required maintenance, just search “water heater t&p valve.” Here’s one chosen at random (NOT an endorsement!):
Water Heater Temperature & Pressure Relief Valve Discharge Pipe
Original reporting: https://www.quora.com/What-happens-when-a-hot-water-heater-explodes-why
It may not be a common occurrence, but water heaters do explode sometimes. Although it might never happen to you, it is good to be prepared anyway. There are some telltale hints that you can keep a lookout for to know when your water heater may be more likely to explode.
Some of these signs include smelling something strange coming from near the water heater tank or from your water. The water may even be discolored brown or rust-colored. Also, the pressure relief valve on top of the water heater may be leaking or letting out water and steam. Your tank may be making funny noises too.
While all of these may be a sign of a pending water heater explosion, it is never a sure thing, just like there is no guarantee that it is not going to explode. In most cases, you will have no warning when it’s going to happen.
But, if your water heater is old and leaking, has a funny smell, or is making noises, you may want to think about getting a new one.
Many people may think that only gas water heaters can explode. But electric water heaters can blow up too. They are both equally likely to become a ticking time bomb. Especially if you have not been properly maintaining your water heater. Maintenance is the number one way to prevent water heater explosions.
Here are some of the signs of possible explosion in detail.
Does it seem like you are running out of hot water more often than usual? Or maybe it is taking longer for the water to get hot. When your water heats up, the minerals in the water sink to the bottom of the water tank.
After a while, the minerals start blocking the heating element under the water heater, meaning the water cannot get hot quick enough. The more minerals at the bottom of the tank, the higher the risk that your tank will explode due to the overheating of the heating element.
Your water heater’s pressure release valve is located at the top of the unit, on the side. It will open when the pressure inside of the tank reaches incredibly high levels, allowing water to exit and decrease the pressure. If you have a leak in the pressure release valve, this means that there is either too much pressure or heat inside of the tank. Either is extremely dangerous and can result in an explosion.
Once a year, you should test your pressure release valve at the top of the water heater. If no water comes out when you open it or if there are leaks around the area, you need to get someone to take a look at it right away. That pressure release valve is what stops your tank from exploding.
If it is not working, you have no failsafe to protect you from a possible catastrophe.
If your water heater tank is leaking from any spot, it could be a problem. But first, check the drain hole in the bottom of the tank to make sure that is not the cause of the leak. If not, you will need a new water heater because you cannot fix a leaky tank.
Does your water heater stink? Some who have had water heater explosions mention smelling a sulfur or rotten egg smell by the tank before it happened. Others say that their water was starting to smell strange. It could be a gas leak, or it may be silt or dirt at the bottom of the tank. Regardless, any of these means you likely need to get a new water heater.
If there is a gas leak, the gas inside could ignite when the light is on. Therefore, if you smell gas around your water heater, shut off the gas immediately and contact a licensed plumber to have a look.
There is a thing called an anode rod in water heaters that protect the tank. If your anode rod is not working, your water will likely start to look or taste bad. It may turn brown or orange, have a gritty feel to it, or taste metallic. If your water starts looking or tasting funny, you need a new anode or maybe even a new water heater.
You should replace the anode rod every three to five years anyway.
Important Tip: If you have hard water, consider getting a water softener of you will be replacing your water heater more often.
all. So, if you start hearing strange noises from the area where the water heater is, it may be cause for concern.
Some say popping or ticking noises were heard just days before their water heater exploded. If your water heater sounds like it is making popcorn, it could fail. Over time, water sediment collects at the base of the heating tank, insulating the water from the burner. As a result, the burner has to run longer to properly heat water, which increases the heat in the tank.
This popping noise you are hearing is coming from water that is trapped underneath the built-up sediment. As it escapes the layer of sediment it is heating and bubbling, producing the strange noise. If you find yourself in this situation, you should shut off your water heater and call a professional right away.
Another reason that hot water heaters explode is user error. If you had your hot water heater installed by someone who is not licensed or did it yourself, it may not be hooked up correctly. The water pressure may be improperly adjusted, the temperature may be too high, or you may have a gas leak.
Even if it may save you money to have someone cheaper hook up your hot water heater, it can be dangerous. Unless they are a licensed professional, you should not try cutting corners there. Just hire an expert to do it. You do not want your hot water to explode or you will have to pay for more than just a water heater.
It is important to have the water in the tank flushed once a year to keep the minerals and sediment from building up at the bottom of the tank. You can do it yourself in just a little while with no special training or tools. Just a few steps done in order will flush the water tank and give you clean fresh water again.
Here are the steps to follow:
No matter how long you have had the water heater, if it is producing any of these warning signs, turn it off and call a licensed professional.
Keep your water heater maintained, flush the tank every year, and check the water relief valve at the same time. Change the anode rod once every three to five years as well. Your water heater should last about 10 to 12 years if you take care of it properly. You may also want to think about switching to a tankless water heater, which typically lasts about twice as long.
A water heater explosion in the home can be absolutely devastating. This extensive system failure can result in massive damage to your home and plumbing system. Not to mention, the sheer force of an exploding hot water heater tank has the potential to injure or even kill occupants. In fact, thousands of children every year are injured from scalding hot water from water heaters.
Original reporting: https://upgradedhome.com/is-water-heater-is-going-to-explode/
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Keep a close eye out for indications that your water heater may be on the verge of exploding, and contact a licensed plumber at the first sign.
Nine recently confirmed cases of Legionnaires’ disease in Hopkins, MN reminded me of an old blog post that I thought would make for a timely re-blog, along with some updated information. First, here’s the story about the recent cases in Hopkins: http://www.startribune.com/mdh-hopkins-warehouse-and-fountain-under-investigation-as-possible-source-of-legionnaires/393567731/. As mentioned in the story, Legionnaires’ disease resembles a severe case of pneumonia and is spread by inhaling the fine spray from water sources containing Legionella bacteria. In your home, the source of that bacteria could be your water heater, especially if you turn your water heater temperature down to the “vacation” setting when leaving for extended periods of time. The people who are most at risk for Legionnaires’ disease are those over 50, smokers, or those with certain medical conditions.
According to LegionellaPrevention.org, legionella bacteria can grow at temperatures from 68° F to 122° F, but the ideal growth range is between 95° F and 115° F. When it comes to preventing legionella bacteria growth, hot water is better. Legionella bacteria cannot multiply at temperatures above 122° F, and are killed within 32 minutes at 140° F. So crank up the water heater as high as it will go, right? No, of course not. That would create a scald hazard. Water heater manufacturers put a warning on water heaters saying the water temperature should not exceed 125° F to help prevent “severe burns instantly or death from scalds”. Their words, not mine.
So what’s the perfect temperature for your water heater?
Unfortunately, there’s no simple answer. The American Society of Sanitary Engineering Scald Awareness Task Group released a white paper many years ago on this topic, which essentially says that there is no perfect temperature to set your water heater to. Part of the reason is that traditional tank-style water heaters don’t keep the water in the tank at an exact temperature; there is a temperature “band” that tank water heaters maintain. At the beginning of a heating cycle, a water heater set to 120°-ish might start at 115° F, and might get up to 125° F at the end of its heating cycle. There’s more to it than just that, but the point is that water heaters do not produce constant temperatures.
If the water in a tank is kept below scalding temperatures, there is a potential for Legionella bacteria growth. Ideally, the temperature in a water heater tank should be cranked way up to 140° F or higher, but now we’re back to the scald hazard thing. One solution is to have a hot water tempering valve installed for the entire home.
This valve would be installed right at the hot water outlet of the water heater. It would allow the water heater to be cranked up to a scalding 140° F, which would be sufficient to kill bacteria and would extend the capacity of the hot water tank, while at the same time reducing the temperature of all of the hot water throughout the house. Click the following link for more information about these devices: http://media.wattswater.com/F-MXV.pdf . While these devices won’t guarantee safe water temperatures at every fixture, they’ll get you a lot closer.
If you want more hot water out of your water heater and you want to reduce the risk of Legionella bacteria growth, hire a plumber to install one of these mixing valves at your water heater and turn the temperature up on your water heater. I should also mention that point-of-use thermostatic mixing valves should ideally be installed at the faucets for the highest level of safety… but I’m pretty sure I’ve never seen a home fully outfitted with those.
Much has already been said about the safety improvements homeowners and business owners can anticipate by switching from traditional water heaters to tankless models.
Usually the discussions have revolved around the half a million scald or burn incidents happening every year, many caused by overheated tap water from an old or uncalibrated water heater. According to the Burn Foundation, more than one-sixth of all childhood hospitalizations from scalds happen because of hot tap water.
That said, another threat endangers those who use both residential and commercial tank heaters: Legionnaires’ disease. What causes Legionnaires’ bacteria to grow and how can traditional tank heaters put your home or business at risk?
“Legionella grow in still warm water.”
What is Legionnaire’s disease?
Legionnaires’ disease is actually a body of diseases – more than 43 according to the U.S. Occupational Safety and Health Administration – all caused by the same bacteria called Legionella. This pathogen grows in still warm water. If inhaled through water vapor, these bacteria could cause fever, pneumonia, comas and even death.
So, how does a standard hot water tank turn into a Petri dish for Legionella? Unfortunately, a few different ways.
How can hot water tanks produce Legionella?
Fiddling with hot water tank temperatures for energy efficiency gains could set off a chain reaction producing Legionella. Many energy experts, including the U.S. Department of Energy, recommend setting hot water tanks to 120 degrees Fahrenheit to shave a few bucks off a home gas bill. Unfortunately, Legionella can survive that temperature and prosper. OSHA recommends keeping tanks at 140 degrees, which effectively neutralizes Legionella-infected water, but hot water at that temperature could easily scald children or seniors with sensitive skin. Either way, water tank owners lose.
“Sediment collecting in water tank can encourage Legionella growth.”
Sediment collecting at the bottom of a dilapidated water tank can also encourage Legionella growth. If tank owners neglect to flush their systems at least once a year to rid systems of calcium carbonate buildup – common in areas with high water hardness – and other debris, Legionella could develop with time.
Legionella also breeds in pipes where stagnant hot water cools below that 120-degree mark. As hot water trapped between a water tank to a faucet or tap cools, it becomes more and more susceptible to infection.
Fight disease with tankless water heaters for your home
Tankless water heaters provide a number of solutions for these problems. First and foremost, automated technology controls hot water temperatures right at the source, so it’s always the perfect temperature: warm enough to prevent waterborne disease, cool enough to avoid scalds and energy-efficient enough to keep monthly bills low.
Point-of-use tankless water heaters not only forego the large cylindrical basin where Legionella can grow, but also reduce the piping needed to deliver water from a utility to the faucet, thus eliminating another threat. Water moves directly from the public system, into the home and right to the tap where it’s heated on demand
.If your hot water heater isn’t working for you, it’s working against you. Choose tankless models to prevent the spread of Legionella, protect your family from overheated water and save money on your energy bill.
Source: Does your hot water heater protect you from Legionnaires’ disease?
Hot water heater tanks, shower heads, hot water taps and pipework can breed Legionnaires Disease bacteria, as it breeds in stationary warm water (25-50°C). To prevent the Legionnaires Disease bacteria from growing in your hot water tank, do not lower hot water tank temperature below 60°C (140°F).
Legionnaires Disease, or Legionellosis, is a sometimes fatal illness caused by a bacteria that can grow in a hot water heater. Legionnaires Disease is a respiratory disease that can cause severe pneumonia when hot water heater droplets are inhaled during a shower. It can also come from a contaminated air conditioning system.
Keeping the hot water heater tank temperature set to a minimum of 60°C (140°F) prevents the Legionnaires Disease bacteria – Legionella pneumophila – from growing. If Legionella infected water is inhaled in small airborne droplets from the water heater, as would happen when taking a shower or whirlpool bath, the individual could end up with Legionnaires Disease.
The Legionella bacteria can multiply exceptionally well in warm water, between 25° to 50°C (77°F to 122°F).
The solution is to keep the hot water INSIDE the tank set to a minimum of 60°C.
This applies to all electric and gas storage tank systems, including solar and heat pump units, which also have storage tanks.
Your plumber would have set your system up to run at 60°C (140°F) when it was installed.
Plumbers know to set the temperature correctly.
Turning your hot water tank down, to save money, can backfire, if you go below 60°C.
The best advice is to leave it as set by your plumber.
Air conditioning system can also be a breeding groud for Legionnaires Disease and require anti-bacterial agents to be added to their water to stop the growth.
Tempering or mixing valves are used to reduce the temperature to prevent possible scalding.
These mix cold water with the hot water AFTER it leaves your tank.
Your plumber will typically set the tempering valve to deliver 50°C water at the hot water tap.
Most tankless hot water systems are factory pre-set to 50°C, so they do not require the use of tempering valves.
The World Health Organisation — WHO — recommends that water be heated and stored at 60°C.
However, Canadian studies have shown, even when the thermostat is set at 60°C, a high percentage — approximately 40% — of electric water heaters remain contaminated because of the lower temperature, about 30°C to 40°C at the bottom of the tank.
No water heaters using gas were contaminated.
The authors concluded that, because of design variables, use of an electric water heater was the most significant factor leading to Legionella contamination in hot water in the home.
Some homeowners unknowingly reduce the temperature setting on their hot water system to conserve energy.
A good idea in theory, but a bad idea in view of the Legionella issue.
Some homeowners shut off their hot water tanks when they go on holiday, but an outdoor hot water tank in the sun may provide the perfect conditions for the bacteria to multiply.
Old or malfunctioning hot water heaters may also have actual temperatures below 60°C, potentially causing the problem.
Regular inspections by a licensed plumber can help ensure that the problem is prevented.
Another solution is the use of continuous flow hot water heaters.
These systems are tankless, so there is no breeding ground for the bacteria.
They heat the fresh incoming water as it passes through the unit.
As they only need to heat the water to 50°C and only run when you need hot water, they save energy and money, too.
Another advantage of continuous flow systems is that they never run out of hot water.
Storage type water heaters are a reliable source of hot water and are used in most households in the U.S. and Canada. Even with advanced heating technologies that exist today, there are still technological limits to controlling hot water tank temperatures using a water heater.
There is a general misconception that a water heater’s thermostatic control can regulate the water temperature at the point-of-use. However, the water heater thermostatic control is typically at the bottom of the water heater, and does not sense the water temperature at the end point-of-use, which can pose a scald hazard for showers, faucets and other points in a household when water is too hot.
Hot water scalding is one of the major reasons why various plumbing codes and manufacturers require that thermostatic mixing valves be installed with water heaters to regulate water temperature at point-of-use.
Keeping water in hot water storage tanks at a temperature that is considered sanitary requires raising the temperature of water to at least 140°F (60°C). But, at 140°F (60°C), water can cause third-degree burns in children in one second and in adults in five seconds.
The American Burn Association states that approximately 21,000 child injuries are directly related to dangerously hot tap water in residences—that’s 65% of all hospitalized burn-related injuries in children under 4 years old1. The answer to preventing harmful water temperatures is to store distributable hot water at a high temperature and temper it to a safer temperature before distribution to the fixture.
Cash Acme’s thermostatic mixing valves mix hot and cold water together upon exiting the storage tank to deliver water at a controlled temperature of 120°F or less to prevent scalding.
Legionella is an aquatic bacteria that thrives in warm water environments and is the cause of Legionnaires Disease. It is commonly found in hot water heaters, potable water supplies, hot tubs, cooling towers, fountains, swimming pools, etc. and multiplies in conditions especially between 68 – 122 °F. The Legionella bacteria can spread to humans when breathed in.
An estimated 22K cases of Legionnaires disease are reported in the U.S. each year2. It is known to cause fever, chills, and a cough, which can be dry or may produce sputum. Some patients also have muscle aches, headaches, tiredness, loss of appetite, and, occasionally, diarrhea. Legionella may also cause cases of pneumonia that may be difficult to diagnose. Of the approximately 2.4 million cases of pneumonia that are diagnosed each year in the United States, about 18,000 are confirmed as Legionnaires Disease and up to 600,000 cases of Legionnaires Disease are misdiagnosed as pneumonia because the hospitals do not perform tests for Legionella.3
Improved design and maintenance of cooling towers, plumbing systems and hot water heaters to limit the growth and spread of bacteria are the foundations of Legionella prevention.
The answer to preventing both Legionnaires disease and hot water scalding is to store distributable hot water at a high temperature and temper it to a safer temperature before distribution to the fixture.
A water temperature of 120°F does not kill the Legionella bacteria; a hot water temperature of 140°F is required at which Legionellae dies in 32 minutes. Hence it is recommended that the water heater be set at a safe hot water temperature of 140°F. The Legionella disinfection range is 158 – 176 °F.
Several countries around the world, including Canada and many in Europe, have adopted regulations requiring water to be stored at a higher temperature and delivered at 120°F or lower. The aggressiveness with which countries have addressed this issue indicates the importance of water storage safety. In fact, according to the Safe Kids Worldwide Campaign, “all code-making bodies at the [U.S.] national and regional level have established plumbing standards for newly constructed homes and residential units requiring anti-scald technology and a maximum water heater temperature of 120 degrees F.”4
Cash Acme Thermostatic Mixing Valves (TMVs) provide safe, in-home water solutions to both inhibit legionella tank growth and prevent water heater scalding and burns. Our TMVs allow water to be stored at high temperatures at the source (hot water heater) and delivered at safe temperatures at the point-of-use (sinks, lavatories, bathtubs or multiple fixtures such as gang showers). By placing a thermostatic mixing valve on a water heater, the heater’s thermostat can be turned up to a higher temperature setting to avoid growth of bacteria. The mixing valve then takes the hot water from the newly set heater and mixes it with cold water until it can be released from the valve at a safe 120°F temperature.
Additionally, the Cash Acme Tank Booster valve can double the hot water delivery in a system, as well as provide all of the other safeguards that our TMV products supply.
References:
1 American Burn Association http://ameriburn.org/wp-content/uploads/2017/04/scaldinjuryeducatorsguide.pdf
2 CDC cases reported from 2000 – 2009: http://www.cdc.gov/mmwr/preview/mmwrhtml/mm6032a3.htm
3 http://www.LegionellaPrevention.org
4 https://www.safekids.org/sites/default/files/documents/skw_burns_fact_sheet_feb_2015.pdf
Almost every checklist of energy-saving tips includes the recommendation that you turn the temperature of your water heater down from 140°F (60°C) to 120°F(49°C). Yet up in Canada if you look for recommendations, they will tell you not to set your heater below 140F, as it can become a sort of petri dish for Legionnaires Disease. When I mentioned this in a comment on an earlier post, commenters went a bit crazy on me, so I thought it would merit a closer look.
Legionnaires Disease, or Legeionellosis, is caused by Legionella pneumophila, an aquatic organism that thrives in natural and artificial environments, such as cooling towers and spa pools.1 It was identified after 34 veterans died after attending an American Legion Convention in the Bellevue-Stratford Hotel in Philadelphia in 1976. It is temperature sensitive:
Because of this, quite a few Canadian sources make the following recommendations.
"To reduce the risk of burns from hot tap water, the temperature setting on the water heater can be turned down. But if the temperature is set too low, bacteria may begin to grow in the tank. Even at 60 °C – the setting on most electric water heaters – an estimated 25% of all water heaters are contaminated by legionella bacteria.
"Legionella bacteria tend to grow in the lower temperatures at the bottom of water heater; such bacteria can cause a form of pneumonia. The organism is generally transmitted when people inhale contaminated water droplets from whirlpool baths, showers or building air conditioning systems. In Québec, about 100 people a year are hospitalized for pneumonia caused by contaminated residential water heaters."
In light of the statistics, it is not advisable to lower the water heater temperature to, say, 49° C. This would not only reduce the hot water supply by some 20%, but it would also put your household at risk of contracting pneumonia. Keep in mind that Hydro Quebec is an electric utility.
"In 2000, the Walkerton disaster had sent a wake-up call about the safety of Canada’s drinking water. While standards for domestic hot water must consider scald prevention, they must also address the broad spectrum of public health and safety issues. To minimize bacteria contamination, water must be stored at 60 C or higher.
"For example, temperatures under 50 C may increase the risk of Legionnaires’ disease, a form of pneumonia, due to bacterial growth in the tank. That disease is caused by Legionella bacteria, which live in water. Temperature is a critical factor for Legionella to grow. The risk of colonization in hot water tanks is significant between 40 and 50 C.
"Legionella bacteria most often enter the lungs due to aspiration. (Aspiration means choking such that secretions in the mouth bypass the choking reflexes and enter the lung.) Drinking contaminated water is not a major cause of Legionnaire’s disease.
"The Centers for Disease Control and Prevention estimates 8,000 to 18,000 Americans contract the disease annually. 4 Five to 30 percent of the cases are fatal. While Canada has no national statistics, Hydro-Québec says about 100 people a year are hospitalized in that province for pneumonia caused by contaminated residential water heaters."
"If you have an electric water heater, do not lower the temperature setting below 60° C. The bacteria that causes Legionnaires disease grows more easily in some electric water tanks because of the way they are designed. You can still lower your water temperature by installing safety valves. Talk to a qualified plumber, the company that made your heater, or the rental company for your water heater."
When one looks for American sources, there are not very many that mention Legionnaires, and they are a little more qualified in their approach:
Q. Can Legionnaires disease be prevented?
A. "Yes. Avoiding water conditions that allow the organism to grow to high levels is the best means of prevention. 5 Specific preventive steps include maintaining domestic water heaters at 60°C (140°F). The temperature of the water should be 50°C (122°F) or higher at the faucet."
Q. Do you recommend that I operate my home water heater at 60°C (140°F)?
A. "Probably not if you have small children or infirm elderly persons who could be at serious risk of being scalded by the hot water. However, if you have people living with you who are at high risk of contracting the disease, then operating the water heater at a minimum temperature of 60°C (140°F) is probably a good idea. Consider installing a scald-prevention device."
This program makes no mention of Legionnaires disease. In regards to water temperature safety, it only says the following:
Set water temperature only as hot as needed (110-120 degrees) to prevent scalds and save energy (check local codes for specific temperatures).
So why is there so much concern north of the border and so little to the south? Perhaps there is more concern about the dangers of scalding than there is about the dangers of Legionnaires disease. In Canada, they recommend mixing valves to eliminate the risk of scalding.
I also think that there is a tendency in the States to assume that "green" means primarily "saves energy," and that the Environmental Protection Agency is far more concerned about reducing energy consumption than it is about the health of its citizens. That is why they promote Energy Star houses that are sealed up tight but do not require ventilation systems and heat recovery ventilators, and perhaps why they ignore the issue of Legionnaires disease in water heaters even though another agency, OSHA, recommends otherwise. Although the EPA is part of the Energy Star program, they certainly don't seem very concerned about the environment inside the houses.
Or maybe Canada is over-cautious.
Original reporting: https://www.treehugger.com/is-it-safe-to-turn-down-your-water-heater-temperature-4858623
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