What Does A Water Heater Expansion Tank Do

Do I Need A Water Heater Expansion Tank in Texas?

I’m curious about the strange-looking tank above my water heater. “My next-door neighbor in North Dallas informed me that I required a ‘extension tank’ for my water heater! Why?” If I turn on my faucet for the first time, I notice a strange variation in my water pressure. “What exactly is going on?” If any of these questions apply to you, continue reading! Here’s all you need to know about the expansion tank, which is often ignored. Please keep in mind that this post is just for informative reasons.

Legacy Plumbing is not liable for any harm or injury that may occur as a consequence of the use or misuse of the information provided.

What does a thermal expansion tank look like?

The most popular domestic expansion tank resembles a small propane tank in size and appearance. The most often encountered hues are off-white or blue. On the top, it contains a Schrader valve, which is similar to the air valve found on the majority of tires. A threaded pipe connector is located at the bottom of the container. It is common for them to be roughly the size of a basketball – or somewhat larger or smaller, depending on the size of the water heaters they service.

How does a water heater expansion tank work?

While heating a kettle of water on the stove, the kettle will ultimately begin to whistle as the pressure that is building inside it causes steam to be released into the air. Regardless of whether or not the water in your water heater reaches the boiling point and condenses to form steam, it does expand when heated. Thermal expansion is the term used to describe this phenomenon. This additional pressure will simply be absorbed by the municipality’s water distribution system and will eventually become insignificant.

If, on the other hand, a check valve or a pressure regulating valve (PRV) is installed on the water supply line entering your home, it prevents all of that extra pressure from being retained in your home’s plumbing system, putting unnecessary strain on your supply lines, fixtures, and appliances.

It absorbs the extra pressure if it is put correctly.

The remaining half of the container is filled with compressed air.

With increasing heat and expansion of the water in your water heater, it presses on the bladder, further compressing the air on the opposite side.

When is it required in Texas?

While heating a kettle of water on the stove, the kettle will ultimately begin to whistle as the pressure that is building inside it causes steam to be released into the atmosphere. Regardless of whether or not the water in your water heater reaches the boiling point and turns into steam, the water does expand as it is heated. Thermal expansion is the technical term for this. As a result, the excess pressure will be absorbed by the municipality’s water distribution system and will eventually be rendered insignificant.

If, on the other hand, a check valve or a pressure regulating valve (PRV) is installed on the water supply line entering your home, it prevents all of that extra pressure from being retained in your home’s plumbing system, putting additional strain on your supply lines, fixtures, and appliances.

One-half of the tank is filled with water drawn from your home’s main water supply.

A pressurized air tank fills the remaining half of the container. Towards the centre of the bladder is a butyl rubber bladder. Water in your water heater heats up and expands, pushing against the bladder and causing it to become even more compressed when it cools down.

Do I need more than one if I have multiple water heaters?

You require a thermal expansion solution that is appropriately scaled for the plumbing system in which it will be installed. It is possible to service a 50-gallon water heater with only one 2-gallon expansion tank, for example. If you have more than one heater on the same or related system, you may either use an expansion tank for each heater or use a single, bigger expansion tank to accommodate the additional heaters. To be sure you have proper information for your circumstance, double-check local plumbing code modifications as well as the manufacturer’s specs for the expansion tank you’re considering purchasing.

What is the life expectancy of an expansion tank?

When it comes to the lifespan of an expansion tank, the results are highly unexpected. There are several elements that might influence how long a tank will endure, including the quality of the tank placed, the quality of the water, and the correct inflation of the tank, to mention a few. We have seen some tanks fail in as short as two years, causing significant water damage, while others have survived for eight years or longer without a problem. If you want to be extra cautious, we recommend that you replace them no more than a year after the manufacturer’s guarantee has expired.

Can my expansion tank leak?

Yes, the expansion tank, like every other component of your home’s plumbing system, is susceptible to breakdown over time. The majority of the time, they fail in two ways. After a period of time, the rubber bladder within them wears out, and the tank ceases to operate as a means of reducing thermal expansion as a result. Secondly, corrosion and leakage might occur at the point of connection between the water pipe and the tank’s pressure relief valve. If you want to be sure that the expansion tank does not cause harm, one thing you can do is have it professionally installed by a competent and certified plumber.

He will also position it (where feasible) above the water heater pan or somewhere else where the danger of harm is minimized in the event of a leakage.

In addition to having a stainless steel threaded connection, high-quality tanks are constructed of high-quality materials such as thick butyl rubber, polypropylene, heavy gauge carbon steel, and so on.

How can I test if my thermal expansion tank is working?

NOTE: Before you begin testing, double-check that the shut-off valve before to the expansion tank is operational. If a catastrophic failure occurs while you are testing, it has the potential to do significant harm. Any testing should be carried out by a licensed specialist, according to us. If you see any evidence of corrosion on the expansion tank connection (as shown in the photographs), immediately stop off the water supply and contact a competent contractor.

Legacy Plumbing disclaims any and all liability for any damages resulting from faulty testing or failure of fittings while testing is being conducted. There are a few things you may perform to determine whether or not your expansion tank is still functional.

Monitor Pressure: Easy

The most straightforward method is to visually monitor your water pressure. If you have a closed loop system and do not have a functioning expansion tank, you may notice that the water pressure fluctuates under specific situations. When there is a prolonged period of high hot water use followed by an extended period of minimal water consumption, pressure will build up in the system. Turn on the hot water faucet and keep an eye on it. It will begin to emerge with a noticeable increase in pressure and then begin to decrease in pressure.

Just keep in mind that this is not a final test of your expansion tank due to the fact that there are other elements that impact flow and pressure.

External Tapping: Easy

The second method of determining whether or not your expansion tank is operational is to tap it with a metallic item. Despite the fact that it is not a foolproof test, it is a fairly simple technique to double-check. The bottom half of an expansion tank that is correctly operating is completely filled with water from your home’s plumbing system. The top of the container is filled with compressed air. If you tap on the top and bottom of the tank with a metallic item alternatively, you should notice a noticeable variation in the noises that are created.

If there is no discernible difference in sound, you may have a faulty expansion tank on your hands.

Check the Valve: Easy

Another, far more reliable method of determining whether or not your expansion tank has been compromised is to bleed a small amount of air out of the Schrader valve located on the top. If air escapes from the rubber bladder, it means that it is still in good condition. If water pours out, it means that the seal has been breached.

Pressure Check: Advanced

Finally, when you have completed the preceding tests and determined that your expansion tank has passed, there is a definite way to establish whether or not your expansion tank is in excellent working order and has been appropriately adjusted. It will necessitate the usage of a water pressure monitor as well as an air pump similar to that which would be used to inflate a vehicle tire.

  1. In the end, assuming your expansion tank has passed the preceding tests, there is a definite way to evaluate whether or not your expansion tank is in excellent working order and has been correctly adjusted. Water pressure gauges and air pumps, similar to those used to inflate a car tire, will be required.

After completing this operation, you can rest comfortable that your expansion tank is now operating as it was intended to do so. When installing an expansion tank, it is typical for plumbers (particularly construction plumbers) to neglect to pre-charge the tank to the necessary pressure before starting the job. If the tank has not already been damaged as a result of the installation issue, this process can fix it.

Do You Still Have Questions?

It is safe to assume that your expansion tank is now operating as it should after completing this operation.

When installing an expansion tank, it is typical for plumbers (particularly construction plumbers) to fail to pre-charge it to the right pressure before starting the job. The tank will not be harmed if this process is performed to repair the installation problem.

What is a Water Heater Expansion Tank and Why Do I Need One?

Regardless of whether the water heater is powered by oil, natural gas or propane, or even electricity, all water heaters are susceptible to the negative effects of thermal expansion as cold water entering the tank is converted to hot heated water. This results in an increase in overall water volume through expansion, as well as an increase in pressure inside the tank. For the sake of general safety, this rise in volume and pressure must be alleviated.

What is an Expansion Tank?

As a result, when the expansion tank is properly designed and fitted, it absorbs the “extra” water into a bladder that is positioned within the expansion tank, reducing the amount of surplus pressure within the water heater unit. Expansion tanks aid in the reduction of water hammer difficulties as well as the protection of the plumbing system from stress and damage, resulting in a longer tank lifespan. These tanks must be appropriately situated, sized, and piped into the overall system in order to be effective, and they should be inspected on a yearly basis.

See also:  How To Check Element In Hot Water Heater

If you’re concerned that your water heater doesn’t have an expansion tank, ServiceMark can assist you with that worry.

Electric Furnaces: Advantages and Disadvantages

What Causes These Plumbing Issues?

The hot water heater in your home is integrated with a check valve, which is inserted in the cold-water feed pipe to improve efficiency and comfort when heating water. Plumbing industry professionals who are licensed to work in the field refer to the check valve and the pipes as a “closed system.” Water flow backward out of the house through the supply pipes is prevented by these one-way check valves, which prevents potential pollution from entering the public water supply. Water pressure builds up in a closed system until the check valve is opened, which is an inherent issue with check valves installed in the system.

If your water heater tank is equipped with a check valve or a pressure-regulating valve, we recommend that you purchase an expansion tank to supplement it.

ServiceMark Can Install Your Expansion Tank!

In addition to being thoroughly trained, our great heating, cooling, and plumbing professionals and support personnel are available 24 hours a day, seven days a week to assist you in making your house not only pleasant, but also safe! We provide same-day service and qualified professionals that are guaranteed to come on time, every time, on the job site. Make a call to the ServiceMark team to guarantee that your house is secure and pleasant throughout the year. This article may be of interest: Should I Repair or Replace My Heat Pump System?

Does My Water Heater Need an Expansion Tank?

In addition to being thoroughly trained, our great heating, cooling, and plumbing professionals and support personnel are available 24 hours a day, seven days a week to assist you in making your house not only pleasant, but also safe. We provide same-day service and qualified experts that are guaranteed to come on time, every time, on the job or at your location.

In order to keep your house secure and pleasant throughout the year, contact the ServiceMark team. This article may be of interest to you: Should I Repair or Replace My Heat Pump System?

How Does an Expansion Tank Work?

An expansion tank is a tank that connects to the cold water line that feeds into the tank of the water heater. A rubber baffle separates the two halves of the cylinder. Heat from the bladder causes it to expand, pushing the baffle downward into a chamber filled with compressed air, which absorbs the pressure. The tension on the tank is relieved, and your plumbing joints, toilet valves, and solenoid valves on your washing machine and dishwasher are protected from harm as a result of this.

How Do I Know If I Need an Expansion Tank on My Water Heater?

It is possible that your residence is on a closed-loop system: In an open-loop system, any extra water produced by thermal expansion would be sent back to the main water supply. All of the additional pressure in your home’s closed-loop system will force the tank to expand and contract, resulting in the unit failing prematurely as a result of the expansion and contraction. Unless your main water shutoff valve is equipped with a pressure regulator, a backflow prevention device, or some other bell-shaped mechanism, you have a closed-loop system in your house.

Pressure regulation will be accomplished by the use of a hot water jet discharged.

If the TPR valve trips on a regular basis, you may require an expansion tank.

Water Heater Tank Maintenance

The compressed air is pumped into the bottom half of the expansion tank, which is typically between 50 and 60 pounds per square inch in compression (PSI). It is possible that the tank will lose some pressure over time. The tank is equipped with a Schrader valve, which is the same sort of valve used on a bicycle tire. Check it with a pressure gauge once a year to ensure that it is adequately charged. Using a bicycle pump, you can pressurize it if the pressure is less than 50psi. The bottom truth is that the water heater installation process is straightforward.

If you are interested in arranging an appointment with PlumbingA/C Medic, please contact (602) 975-2306.

Do I Need an Expansion Tank on My Water Heater?

Please keep in mind that this content may contain affiliate links. This means that, at no additional cost to you, we may gain a small profit on purchases made via our links. We will answer these questions and provide you with a better picture of what is happening with your water heater if you continue reading.

What Type of Water Heater Do You Have?

This may appear to be a simple question, but it is one that many people do not actively consider when they are faced with it.

Due to the fact that a tankless water heater lacks a primary tank, you will not need to bother about an expansion tank. If you have a typical tank-style water heater, on the other hand, you will almost certainly need to examine whether or not an extension tank is required.

What Does an Expansion Tank Do?

First and foremost, you must comprehend how your water heater operates. When the water in your water heater is heated, it expands as it cools. Thermal expansion is the term used to describe this process, which can put a strain on your plumbing system. What happens is that if your water heater stores 50 gallons of cold water, it will expand to around 52 gallons once it has been warmed up. As a result, if the excess volume has nowhere to go, it will press against the walls of your plumbing system.

  1. Your water heater is analogous to this paper clip; if there is enough pressure built up from the expanding and contracting, the tank itself can begin to leak or even rupture.
  2. Unfortunately, many residences have closed water supply systems, which means that the water supply is only available in one direction.
  3. The manufacturer of your water heater may even invalidate your guarantee if you do not use an expansion tank in conjunction with your closed system, according to the manufacturer.
  4. You may, on the other hand, hire a plumber to complete this particular work for you if necessary.
  5. Your expansion tank may be able to assist you in saving your system.
  6. The expansion tank acts as a fail-safe device, preventing your plumbing from becoming overworked.
  7. This, in turn, shields it from further harm.

What Size Expansion Tank Do I Need?

First and foremost, you must comprehend how your water heater operates and functions. During the heating process, the volume of water in your water heater increases. As a result of this phenomenon, which is known as thermal expansion, your plumbing system may be put under pressure. According to the way it works, say your water heater contains 50 gallons of cold water, it will expand to around 52 gallons once it has been heated. It is possible that the excess volume will press against the walls of your plumbing if it has nowhere to go.

  • When there is enough pressure from the expanding and contracting, the water heater tank itself can begin to leak or even explode, similar to how a paper clip does.
  • The unfortunate reality is that many homes are equipped with one-way valves that prevent the water from flowing backward.
  • In fact, if you do not use an expansion tank in conjunction with your closed system, the manufacturer of your water heater may possibly invalidate your guarantee!
  • This particular work, on the other hand, may always be contracted out to a plumber.
  • If your system is in danger, your expansion tank can help you save it.
  • To keep your plumbing from being overworked, the expansion tank is used as a backup system.

Instead of putting too much pressure on the piping, the surplus water volume rushes into the expansion tank, where it decreases the pressure in the water heater to a safe level before being released. Final protection against harm is provided by this.

  • Chart from PlumbingSupply.com
  • SupplyHouse.com calculator
  • HomeDepot.com expansion tanks
  • And more.

You may, on the other hand, find yourself in a position where you are unclear if the size of the expansion tank is appropriate. In order to avoid selecting an expansion tank that is too small, it is customary to pick one that is somewhat bigger than necessary. This is due to the fact that a tank that is too small might result in the discharge of the relief valve. On the other hand, if the tank is overly large, it will have no detrimental affect on your plumbing system whatsoever.

So Do You Need an Expansion Tank?

If you have a standard storage tank water heater, the chances are good that you do. To be certain, conduct thorough research on your specific type of water heater or consult with a plumbing professional. This is one of those things that you want to make absolutely certain you have done correctly.

Do You Need a Water Heater Expansion Tank?

Through the usual thermal expansion that occurs when water is heated, a typical tank water heater can cause stress on your plumbing pipes and fixtures in a closed plumbing system. Basically, any closed system where water is heated can have an issue with this. Both water heaters and boilers for home heating systems might be susceptible to this type of damage if no precautions are taken to avoid it from occurring. When used in conjunction with a plumbing system, a water heater expansion tank can help to reduce the likelihood of pressure damage to the plumbing system occurring.

Only older models with storage tanks are susceptible to this problem.

What Is a Water Heater Expansion Tank?

An expansion tank for a water heater serves as a safety precaution (sometimes called a thermal expansion tank). As the name implies, it is an overflow receptacle that helps to relieve pressure created by the typical thermal expansion that occurs when water is heated. It functions as an overflow receptacle by absorbing surplus water volume that happens during the heating process, as well as changes in the incoming water supply pressure, which are all absorbed by the expansion tank. Because water expands when heated owing to thermal expansion, every time the water heater heats water, the water heater adds to the total amount of water in the tank.

This increased water volume can result in a rise in pressure in the plumbing system, which, if the pressure is high enough, can cause damage to the water heater, plumbing fixtures, and the water pipes themselves over time, depending on the situation.

Closed Water Supply Systems

An expansion tank for a water heater serves as a safety precaution (sometimes called a thermal expansion tank). As the name implies, it is an overflow receptacle that helps to relieve pressure created by the typical thermal expansion that occurs when water is heated. This tank functions as an overflow receptacle by absorbing the surplus water volume that happens when water is heated. It also serves to absorb changes in water supply pressure that occur when the water is heated. As a result of thermal expansion, water expands as it is heated, resulting in the creation of more water volume every time it is used to heat water.

Excess pressure in the plumbing system can result from the increased amount of water flowing through it, and if the pressure is high enough, it can cause damage to the water heater, plumbing fixtures, and the actual water pipes themselves over time.

How a Water Heater Expansion Tank Is Installed

In the event that you do not have a one-way valve put on the main water line and, as a result, do not have a closed water system, a water heater expansion tank may still be beneficial to you in some circumstances. It is customary to put expansion tanks above the water heater, on the cold water line before it enters the water heater; however, they can be positioned virtually anywhere on the cold water line prior to entrance into the water heater. The presence of an expansion tank helps to avoid leaky faucets and running toilets by preventing the additional pressure that has built up in the system from reaching the fixtures and causing them to fail prematurely.

See also:  How To Change Water Filter In Kenmore Refrigerator

A basic 2-gallon tank will suffice for the majority of household setups that use 40- or 50-gallon water heaters.

If there isn’t currently a tee fitting placed above the water heater, one will need to be installed as soon as possible.

If it is done at the same time as your other bills, it may not cost much more than you are already paying.

Do I Need a Water Heater Expansion Tank?

The installation of a water heater expansion tank is still recommended if you do not have a one-way valve put on the main water line, and hence do not have an entirely closed water system. It is customary to put expansion tanks above the water heater, on the cold water line before it enters the water heater; however, they can be positioned almost anywhere on the cold water line prior to entrance into the water heater. By preventing the additional built-up pressure in the system from reaching the fixtures and harming them prematurely, an expansion tank can assist avoid leaky faucets and running toilets.

Simple 2-gallon tanks are sufficient for the majority of household setups using 40- or 50 gallon water heaters.

Unless one is already there, it will be necessary to install a tee fitting above the water heater.

If you do it all at the same time, it may not cost much more than you are now paying. In the event that you are building a water heater yourself, consider adding an expansion tank even if it is not necessary, since the advantages greatly exceed the time and expense involved in the process.

Why Do We Need Water Heater Expansion Tanks?

First and foremost, if you do not have a storage tank water heater, this essay will not be of any value to you at all. Extension tanks were developed solely to address a problem that was unique to storage tank water heaters: overheating. When water is heated, the water within your water heater expands, and this is a special problem to be aware of. Thermal expansion is the term used to describe this phenomenon. As an example, when heated, a tank that stores 50 gallons of cold water will expand to accommodate 52 gallons of cold water.

It is likely that those two more gallons will put additional pressure on your plumbing system.

This pressure can be alleviated by using a water heater expansion tank, which gives just enough extra capacity.

Isn’t My Water Heater Equipped to Deal With This Already?

You might be wondering: If the phenomenon of thermal expansion is so simply known, why aren’t water heaters in Glendale, AZpre-engineered to cope with this problem from the start? They are, in fact, correct! Check valves and temperature-regulator valves are commonly seen in water heaters to tackle this problem. The true source of the problem, on the other hand, is the way the plumbing systems are set up between the city and your property. These water delivery systems can be either open or closed, depending on their design.

This completely eliminates the problem, allowing you to utilize your water heater without the need for an expansion tank.

The most likely case, on the other hand, is that you have a water supply system that is closed.

However, even with the valves stated above in place, the pressure caused by thermal expansion cannot be fully alleviated at this time.

Does My Water Heater Need an Expansion Tank?

Checking to see what sort of plumbing system you have is the most straightforward solution. In the event that your home is connected to a closed water distribution system, we strongly advise that you install an extension tank. Don’t underestimate the harm that may be done if you don’t have one—in several areas throughout the country, expansion tanks are now required by law! We can assist you in determining whether or not your property requires a water heater expansion tank. To obtain an estimate, please contact The Trusted Plumber right now.

in Water Heaters |

Water Heater Expansion Tanks: What You Should Know

A water heater expansion tank, also known as a thermal expansion tank, is a safety device that is meant to protect your domestic piping from thermal expansion when your water heater is operating. Tankless water heaters are rarely at danger of pressure damage due to thermal expansion, but if you have an older tank-style water heater, your plumbing system may be at risk.

The additional 2-gallons of water will not fit in the water heater’s tank when you consider that 50-gallons of cold water will become at least 52-gallons after it is heated, thanks to thermal expansion. In this case, the use of a thermal expansion tank is necessary.

What is a Water Heater Expansion Tank?

An expansion tank for a water heater is just a tiny tank that absorbs water into a bladder in order to relieve excess pressure in your water heating system. Once upon a time, when water expanded, it didn’t cause an issue since the extra few gallons just flowed back into the city’s water supply system. However, because existing plumbing laws restrict the increased water from entering the city’s system, where it may contaminate the public water supply, the expanded water has nowhere to go for the time being.

Consequently, there is an increase in needless wear and strain, which can lead to damage to hot water-using equipment, including your water heater.

An expansion tank for a Watts DET-5 water heater.

How a Thermal Expansion Tank Works

It consists of an expansion tank with a compressed air bladder within, which absorbs any extra water by expanding and compressing repeatedly. As the water in your water heater heats up, it expands, increasing the pressure within the tank and throughout the rest of the plumbing system. The extra water, however, enters the expansion tank rather than letting the pressure to build up to a dangerous level. When a faucet in the home is opened (or the water cools), the water in the thermal expansion tank is released back into your hot water system.

Water that has overflowed into the expansion tank is disposed of in the waste tank.

Watch the Video

It is dangerous to use a water heater without an expansion tank. Despite the fact that many water heaters do not come with an expansion tank, we strongly recommend that you install one. It will keep your pipes, appliances, and water heater safe and secure. In the event of an overflowing hot water supply, the pressure in the water tank may grow to dangerous levels, resulting in the failure of several components. It is possible that excess hot water may seep out via the T P Valve and create considerable water damage, as you might expect.

The extra strain placed on the heater as a result of an excessively full tank of hot water might limit the heater’s service life, not to mention the fact that the heater’s components may wear out sooner than intended.

Finding the Right Water Heater Expansion Tank

A hot water heater expansion tank is not only a wonderful idea, but it is also required in most locations, so choosing the appropriate size for your system is critical. It’s unfortunate that when it comes to thermal expansion tanks, there isn’t a “one size fits all” solution available.

How to Properly Size an Expansion Tank

Choosing the appropriate size is a rather simple process.

There are two key considerations that must be taken into consideration:

  • Finding the appropriate size is a rather simple process. For the sake of this discussion, there are two key aspects to consider:

Keep in mind that if your water pressure is higher than 80 psi, you should consider installing a pressure reduction valve. The optimal water pressure is between 50 and 60 pounds per square inch (psi). Gauge for measuring water pressure This water pressure gauge is equipped with adapters that allow you to measure the water pressure in a variety of locations with ease.

General Guidelines for Sizing an Expansion Tank

Always remember that if your water pressure is more than 80 psi, you should install a pressure-reducing valve. Ideally, the water pressure should be between 50 and 60 pounds per square inch. Meter for measuring the amount of water that is being produced. It comes with adapters that allow you to measure the water pressure in a variety of locations using this water pressure gauge.

Water Heater Capacity Supply Pressure (psi) Expansion Tank Size
40 to 60-gallon 40-50 psi 2-gallon
40 to 60-gallon 60-80 psi 3.2-gallon
80-gallon 40 psi 2-gallon
80-gallon 50-60 psi 3.2-gallon
80-gallon 80 psi 4.4-gallon

If your water heater’s static supply pressure readings or capacity go outside of these ranges, it’s recommended to consult with a specialist. They may come out and perform the necessary calculations, as well as build the expansion tank if you so want it. Amtrol Expansion TankAmtrol manufactures a fantastic 2-gallon water heater expansion tank that is both durable and affordable.

What Happens if the Expansion Tank is the Wrong Size?

It is critical to choose the proper size thermal expansion tank, however if in doubt, it is better to err on the side of caution and get a larger tank rather than a smaller tank. Even if you have an expansion tank that is too large for your system, it will be able to manage the additional water safely. A tank that is too small, on the other hand, might cause the temperature and pressure relief valve to open, allowing the excess pressure to be released.

How to Install an Expansion Tank

The installation of an expansion tank should be doable for anyone who has a basic understanding of mechanics and enjoys doing things for themselves. Alternatively, you may hire an expert to complete the task for you.

Installing an Expansion Tank

  • As previously said, a pressure gauge should be used to assess the water pressure in your home. If the pressure is greater than 80 psi, a pressure decreasing valve should be installed. Make that the air pressure in the expansion tank is correct using an atire gauge. The air pressure in the expansion tank should be adjusted to meet the maximum water pressure in the home. Making use of a hand pump rather than an air compressor
  • Installation Instructions: Connect the tank to the cold water line (see video for details)
  • Open a faucet and turn it on until you get a constant stream of water coming out of it. This will release any trapped air that may have accumulated within the tank.
See also:  How Long Does It Take To Change A Water Heater

Watch the Video

Water heater expansion tanks require routine maintenance to ensure that they operate at peak performance. Every year, the majority of experts suggest that you or a competent professional do routine maintenance on your equipment.

Why is Maintenance Needed for an Expansion Tank?

Expansion tanks are constructed with an interior bladder that divides the contents of the tank into air and water. The bladder will begin to leak air as a result of a process known as diffusion. One psi of pressure every year can be experienced by the leak, which is sufficient to notice a difference after only 12 months. Upon rupture of the internal bladder, the expansion tank will fill with water and will fail to drain completely. It is not possible to repair the bladder in this situation, thus you will need to acquire a new expansion tank.

Checking the Bladder

We’ll offer you a simpler technique, but if you hire a professional to examine your expansion tank, he’ll follow these procedures to ensure that it’s in proper working order:

  • Even though we’ll provide you with a simpler way, if you hire a professional to examine your expansion tank, he’ll follow these steps:

To examine your tank quickly and easily, you may just press the Schrader valve, which is positioned on the exterior of the tank and can be reached by pressing the button on the side of the tank.

When you press down on the valve, air should hiss out, which indicates that the bladder is in excellent functioning order. The bladder, on the other hand, will most certainly burst if water starts flowing out instead, in which case you will need to get a new one.

Checking the PSI

After ensuring that the bladder is in excellent working order, you’ll want to check the psi pressure in the tank. The right pressure for your tank may be found in your owner’s handbook. In order to avoid having to look this number up again in the future, you may wish write this number down on your tank’s sidewall. Utilize a tire pressure gauge to obtain the reading. If the pressure is too high, you may simply release some air by pressing down on the valve until the desired amount of air has been released.

When adding air, we strongly recommend that you use a hand pump rather than an air compressor.

Watch the Video

Last updated on February 25, 2022 / Affiliate links included / Images sourced from the Amazon Product Advertising API

Expansion tank dos and don’ts

With increasing temperature, the amount of space required by each molecule rises. Any effort to halt this expansion will be greeted with overwhelming forces of opposition. When water is heated in a sturdy metal container that has been entirely filled with liquid and sealed from the atmosphere, the pressure inside the container rapidly increases. If this pressure is allowed to build up for an extended period of time, the container may finally explode, often violently. Closed-loop hydronic systems are provided with an expansion tank in order to avoid this outcome.

  • Consider the air in the tank to be like a spring.
  • Because of the cooling and contracting of the water, the “spring” returns to its previous state.
  • An expansion tank of this sort is generally suspended from the ceiling of a mechanical room to provide more space.
  • In Figure 1, you can see an example of such a tank in action.
  • As a result, they are more costly, heavier, and need a larger mounting area.
  • Today’s hydronic systems, particularly in residential and light commercial building applications, are rarely equipped with these devices.
  • When the air side of the tank is compressed, this diaphragm conforms to the interior steel surface of the tank, as seen in Figure 2.

When the system’s water heats up and expands inside the tank, the diaphragm deforms and travels toward the captive air chamber, causing it to rupture.

Even if the entire system achieves its maximum temperature, a correctly sized tank will prevent the pressure relief valve from opening due to an increase in system pressure that is not sufficient to release the valve.

One or more additional industry publications, as well as reference 1, provide a thorough process for sizing diaphragm-type expansion tanks.

The diaphragm does not begin to compress until the water temperature gets over a certain point.

When all fluid in the system is at its highest expected temperature, size the tank so that the pressure at the system’s pressure relief valve is 5 psi below the valve’s rated opening pressure.

Even when an expansion tank is appropriately designed, the manner in which it is installed may make or break its capacity to work as intended and to give many years of reliable service.

4: Diaphragm style expansion tank mounted on a wall a.

This reduces the pressure drop between the point where the tank is connected to the circuit, which is the point where there is no change in pressure when the circulator is turned on, and the intake of the circulator.

Increased system pressure helps to protect the circulator against cavitation and, in many cases, provides for quieter operation of the circulator itself.

The tank is shown in Figure 3 in a variety of appropriate locations.

When compared to horizontal installation, this minimizes the amount of stress on the tank’s connection.

The differences are seen in Figure 4.

Verify the air pressure in the tank: It is critical to ensure that the air side pressure in the tank equals the static pressure that will be present at the tank’s connection when the system is filled with cold fluid before proceeding.

Do not take this to mean that it is always right or truthful.

Higher air pressures are required for taller pipe systems in order to avoid partial compression of the diaphragm before the fluid is heated.

Formula 1 is a racing series that takes place on the track.

Static pressure of 5 psi is needed at the top of the system for air vent functioning.

The following is an example: If the top of the pipe system was 25 feet above the top of the expansion tank connection and assuming the system was completely filled with water, then this is the right air side pressure in the tank: Purchase a low-pressure tire gauge with a scale ranging from 0 to 30 psi as well as a bicycle pump or small air compressor to complete the task.

4.

Some tanks fail when a leak develops in the diaphragm of the tank’s main body.

This may be verified by inserting the stem of the Schrader valve into the valve body.

Tanks can potentially suffer leaks due to the thin steel casing that surrounds them.

This is where having a ball valve that can isolate the tank from the rest of the system will be quite beneficial.

5.

It is OK to use a larger tank, even if it will be more expensive.

In most hydronic heating systems, the size of the expansion tank and the air side pressurization are calculated on the premise that the cold fluid used to fill the system is between 45 and 60 degrees Fahrenheit (45 to 60 degrees Celsius).

The antifreeze solution, on the other hand, will occasionally be significantly colder, maybe even below 0F, if an expansion tank is used in a solar collector circuit or a snowmelting system, depending on the application.

Refer to Reference 2 for information on how to account for this possibility.

7.

The larger the concentration of antifreeze in the solution, the greater the volume of expansion required.

When a 50 percent solution of propylene glycol is heated from 60 degrees Fahrenheit to 180 degrees Fahrenheit, the volume increases by approximately 4.5 percent.

Once again, the procedures in Reference 1 can be modified to account for this.

Use of a typical expansion tank with a carbon steel shell in any form of open loop application, such as a system that uses potable water to transport heat to hydronic heat emitters, is not recommended for several reasons.

Additionally, this restriction applies to closed-loop systems that use non-barrier PEX tubing or other materials that may allow oxygen to diffuse throughout the system.

The expansion tank is located near the hydraulic separator in Figure 5.

This causes dirt that has accumulated at the bottom of the separator to fall into the expansion tank as a result of the operation.

Figure 5 shows an example of how to mount the tank from a tee in either pipe connecting to the lower sidewall connections on the hydraulic separator.

Make sure you don’t overheat it: Whenever possible, avoid placing expansion tanks in close proximity to sources of extremely hot water such as boilers.

This raises system pressure in comparison to a condition in which the tank shell is colder, provided that all other parameters are equivalent.

It is OK to place the tank several feet away from the point at where the tank’s tubing joins to the rest of the system.

The use of two or more expansion tanks with a total capacity equal to that of a single bigger tank is acceptable; however, multiple connection points should not be used at the same time.

It is best not to connect numerous tanks to separate sections of the same plumbing.

Figure 6: Tank shell is secured with a strapping technique.

Do not expose it to the risk of being impacted: In the event of an unintended collision, such as someone rising up from a leaned over posture and hitting the tank, small expansion tanks that dangle from 12 in.

Inquire as to how I know this.

Some expansion tank manufacturers provide strapping kits or other hardware to ensure that the tank shell is properly supported.

Both tanks are linked in parallel to a common pipe, providing for a single point of access to the circuit from either tank.

Do not make the assumption of compatibility: Make certain that the expansion tank you choose is compatible with the fluid that will be utilized in the system.

Different tank suppliers, on the other hand, utilize a variety of different materials and have varying temperature restrictions for those materials.

Expansion tanks perform a straightforward but critically important function.

Engineer John Siegenthaler graduated from Rensselaer Polytechnic Institute in Mechanical Engineering and is a licensed professional engineer in New York State.

Heating Using Renewable Energy is Siegenthaler’s most recent publication (see more information).

1.Modern Hydronic Heating, Third Edition, John Siegenthaler, Cengage Publishing 2012. Cengage Publishing published a book in 2017 called Heating with Renewable Energy by John Siegenthaler, with the ISBN-13: 978-1-2850-7560-0. Advertisement

Leave a Reply

Your email address will not be published.