Where Does The Expansion Tank Go On A Water Heater

Water Heater Expansion Tank

Consider the interior of your home’s water heater with an excessive amount of pressure in it. Previously, any pressured water that accumulated would just drain back into the city’s water distribution system. However, this is not always feasible. It’s likely that something is in place to prevent this discharge, but you’ll still need additional protection, which gets us to the water heater expansion tank. It is an additional tiny thank you that is added to your water heater unit and serves the purpose of storing water.

If your home’s water pressure becomes excessive, the water will flow into your expansion tank rather than harming your home’s plumbing valves, fixtures, and joints or triggering a burst line that would cause irreparable damage and cost.

When water is heated from 50 degrees Fahrenheit to 120 degrees Fahrenheit, it expands by approximately 2 percent.

The tank is divided into two portions by a rubber valve.

Water runs through the top section, and pressured air is contained inside the bottom portion.

Common questions about water heater expansion tanks include:

An example of a check valve is a device that prevents the backflow of thermally expanded water in the incorrect direction. If you don’t have an expansion tank, the extra pressure might put undue strain on your plumbing fixtures, including your water heater, shortening their lifespan.

Does the expansion tank have to be installed on the cold side?

We highly urge that expansion tanks be put on the cold line, downstream of the shutdown valve, even if they can be installed on the hot side.

Where should an expansion tank be installed in relation to the hot water heater?

The location of your expansion tank on your plumbing system is entirely up to you; it is not required to be built in close proximity to your water heater. The most frequent method of installation is to use a “T” at the cold water heater’s intake valve. However, it may be put anywhere along the cold inlet line in terms of functionality.

Can the expansion tank be installed at any angle? Pt. 1

It is possible to place the expansion tank at any angle. This will be in contradiction with the information provided with any expansion tank purchased from a retail retailer. According to the installation instructions that come with retail expansion tanks, the tank must be put in a hanging vertical position to function properly. “Saddle Fitting” is included with your retail expansion tank purchase when you purchase it from a retailer.

This eliminates the need for soldering and makes the process of installing an expansion tank simpler for the general public. The saddle fitting is a basic clamp that attaches to the pipe. It also has threading that allows you to attach the tank to the saddle fitting.

Can the expansion tank be installed at any angle? Pt. 2

To begin, you must first create a tiny hole in the current pipe. As a last step, the clamp should be tightened so that the hole lines up perfectly with the outlet for the expansion tank. Despite the fact that this is a possibility, we do not advocate these fits for a variety of reasons. Their reliability is questionable since they only allow the tank to be positioned in one position (vertical). As an alternative, we propose that you solder the appropriate fittings into the system or that you use galvanized fittings.

How to know if you need a water heater expansion tank replacement

The lifespan of a typical water heater is estimated to be 10-15 years; however, your expansion tank may fail before this time. First and foremost, effective installation of your expansion tank will guarantee that the air pressure in the tank is equal to the water pressure in your house, hence extending the life of the tank. By examining your expansion tank on a regular basis, you may avoid a potentially costly mishap. If you notice dripping water under the tank or near the fittings, it is possible that the valve has become clogged.

A pressure gauge, for example, should be installed to monitor the pressure in the tank.

It is possible to replace a water heater expansion tank without having to replace the complete system in most cases.

Who needs a water heater expansion tank?

It is possible that thermal expansion will cause considerable pressure rises in your household plumbing system if you have a “closed system,” which means that your home is protected by a backflow preventer or other device that prevents your water from flowing back into the main water supply. In these conditions, not only should you have a thermal expansion tank, but some towns may also compel you to have one. Furthermore, if you have a closed system and do not install this protection, your water heater’s manufacturer may invalidate your guarantee.

Similarly, if your property is served by an open water supply system, where excess water is recycled back into the municipal water supply, your home’s plumbing system will not be subjected to any additional pressure.

Locating an Expansion Tank

An expansion tank, such as the one seen above, aids in the absorption of water pressure caused by thermal expansion of the water. The tank can be positioned anywhere in the cold-water line between the house’s main valve and the water heater, or on the hot-water line within 3 to 5 feet of the water heater, depending on the situation. In high-pressure circumstances, it is recommended that an expansion tank be placed in combination with a pressure-reducing valve.


I’m in the process of putting up a hot-water expansion tank.

Do I put it in the hot-water line or in the cold-water line, depending on what I’m doing? How far away from the shutdown valve does the tank have to be in order to be compliant? James Heather contacted me via email. None


In response to your inquiry, Georg Efird, proprietor of A2Z Plumbing Inc. (in Asheville, North Carolina), says: “Your question is a typical one, even among plumbers and builders.” First and foremost, it is critical to recognize that the tank’s primary function is to limit thermal expansion. If the water is heated and pressured in a water line, thermal expansion will occur. Typically, an expansion tank has a tiny amount of air divided by a diaphragm, which absorbs the increasing pressure as it builds up.

  • In most cases, if your water heater is leaking or drips from the pressure-relief valve on the top or side, it is most likely because the system does not have an expansion tank or a pressure-reduction valve installed.
  • The reason for this appears to be that they want to utilize the shutdown valve at the water heater for servicing the expansion tank, or that they don’t realize there are any other choices available.
  • This device should be installed in the biggest pipe closest to the entering main, immediately after a pressure-relieving valve.
  • A competent plumber should inspect the tank on a yearly basis, and it should always have the necessary air pressure within it.
  • Consult with a plumber or a plumbing authority to ensure that your work complies with or exceeds local requirements.
  • Get professional advice, deals, and home-building suggestions delivered directly to your email.

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.

  1. 4.
  2. Some tanks fail when a leak develops in the diaphragm of the tank’s main body.
  3. This may be verified by inserting the stem of the Schrader valve into the valve body.
  4. Tanks can potentially suffer leaks due to the thin steel casing that surrounds them.
  5. This is where having a ball valve that can isolate the tank from the rest of the system will be quite beneficial.
  6. 5.
  7. 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 scenario.


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 enable 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 feasible, 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.

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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 include strapping kits or other gear to ensure that the tank shell is adequately 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 used 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 with 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

Where are Thermal Expansion Tanks Installed: Illustrated Guide

First and foremost, we must understand what an expansion tank is before we can consider where it should be built and whether it should be on a hot or cold water line. When a heating system is constructed, an expansion tank is placed to safeguard fixtures and pipes in a plumbing system that does not include a backflow preventer or check valve. Most local plumbing standards require the installation of an expansion tank when a new water heater is connected to the municipal water supply in the majority of situations.

The majority of the time, expansion tanks are erected in an upright posture.

In a water heater, an expansion tank is a small air-filled tank that serves as an expansion chamber, allowing the increased water volume that results from the heating and expansion of water to be controlled.

How an Expansion Tank Works

In some cases, an expansion tank is necessary, and it can assist a water heater last for a longer period of time. The fact that water expands when heated is common knowledge. If there is no expansion tank connected to the water heater, any closed plumbing system that is subjected to thermal expansion would suffer significant damage. For example, when you heat water from 50 degrees Fahrenheit to 120 degrees Fahrenheit, the volume of the water increases by approximately 2 percent. If you have one installed, it provides additional room for hot water expansion, therefore alleviating excess pressure on the pipes, fixtures, and water tank.

Backup valves, also known as pressure-limiting valves, keep the expanding water from running back into the central water supply unit where it came from.

Expansion Tanks Might Be Mandatory

A plumbing permit is required for the installation of a water heater. Obtaining a plumbing permit provides you with the opportunity to find out more about the criteria for an expansion tank. In most circumstances, however, you may be required to construct a water tank in a location where you already have a water heater by your local authorities. An expansion water tank, on the other hand, is not required if your system is not equipped with any backflow or pressure limiting valves. If your system already has such valves in place, it would be a good idea to add the tank even if your local code does not mandate that you do so.

Where to Install an Expansion Tank

Where would you put a new expansion tank, if you had to? First, install a tee-fitting above the water heater on the cold water supply line to prevent water from escaping. Typically, the tank is placed horizontally on the ground. However, if you have a limited amount of available space, you may put the tank vertically instead. The sorts of plumbing fittings you’ll need for installation may vary depending on the type of pipes you have and the orientation of the tank in question.

Copper fittings and pipes are used to make connections throughout the installation process. The expansion tank is connected to the cold water pipe by a 3/4-inch fitting, which is threaded or sweat-soldered to the cold water pipe, or by a short piece of pipe.

Supplies and Tools You Need During Installation

You’ll need a variety of supplies and tools to complete the installation of an expansion tank, which are outlined below:

  • Thermal expansion tank
  • 3-4 inch copper tee fittings
  • Copper flex pipes
  • Pipe-sealing tape
  • 34 inch copper pipe
  • Copper tee fittings
  • 34 inch copper pipe nipple for a dielectric water heater
  • A soldering iron for the plumbing industry
  • Pliers with a channel lock or a pipe wrench
  • Copper unions with female threads of at least 34 inches
  • An additional copper fitting of 34 inches

Preparations for Installing an Expansion Tank

Adding another expansion tank on top of an existing one is possible if you already have one installed. To do so, empty the water heater first. Make sure that you have adequate room above the water heater to accommodate an expansion tank before you begin your installation. If you are installing anything entirely new, there is no need to drain anything. As a result, it would be advisable to move ahead to the steps involved in installing the tank altogether. As a starting point, let’s look at how you may prepare for installation by emptying the tank:

  1. The first step is to turn off the mainline water supply that is directly connected to the cold water side of the heater
  2. The next step is to connect a hose to the drain valve below the heater and run it to the other end of the nearest drain
  3. The final step is to turn off the mainline water supply that is connected to the hot water side of the heater
  4. By opening the drain on the hot side of the closerfaucet and the water heater, you may relieve pressure in the tank of the water heating system. It is important not to open the valve too quickly or too much, since this may cause the drain to fall out. After allowing for a few minutes of draining, open the T P valve just a little to check the pressure. If there is no time constraint, go to step 5. Wait for a few minutes and then repeat step 4 if you feel any pressure at all. Once you observe that there is no more pressure coming from the water heater, you may finally shut off the faucet and turn off the drain valve.

Steps to Installing an Expansion Tank

Following the completion of the preparations, it is now time to install. First and foremost, if you want to be successful, you must adhere to a set of guidelines or procedures. Take a look at the following steps:

Make a Plan

Nothing worthwhile gets off to a successful start without a strategy. Even the most successful military expeditions begin with a plan on paper, no matter how effective the mission is. For this job, you’ll need a solid design for diverting a branch line from the hot water tank’s cold water application to the expansion tank. Please draw a graphic of the situation. You may also purchase the fittings that you will need to run a line from the expansion tank up to the tee-fitting that will be placed into the cold water supply line, if you so want.

At least one elbow fitting is normally necessary in a given situation.

Choose Your Spot

If you already have PEX lines in your flat, the installation may be a little less complicated. If there are copper wires, everything is still possible, but more difficult and time-consuming. In this case, the first step is to determine the precise spot where you would want to install the expansion tank. The expansion tank should be 18 inches above the water heater when installed properly. Additionally, it should be closer to the water heater. Probably not, unless you’ve come across any that are attached to a copper pipe that sticks straight up in the air.

It is possible that the copper pipes will rupture at any time, resulting in your basement becoming a swimming pool.

These mounts are compatible with virtually any tank and are sure to keep yours safe.

Acquire Relevant Hardware

Additional hardware, in addition to tank brackets and the expansion tank, is required to finish the project, which you must obtain. Among these are a few fittings, a roll of Teflon tape for constructing a reliable connection, and a fitting that connects your expansion tank to the appropriate size water lines. Push-to-link fittings made of PEX can be used. If you have copper, on the other hand, you may do one of the following things: get some PEX push that can fit fittings because they link PEX and copper pipes, or purchase a copper fitting and learn how to braze it together.

It is possible that you may be required to cut a small section of the copper pipe cold water supply before inserting the aPEXtee-fitting. However, this is a straightforward activity that you may complete on your own. Replace any galvanized steel pipes that you may have if you still have them.

Mount Bracket and Prepare Tank

In this case, the first step is to secure the connection fitting to the end of your expansion tank with Teflon tape, which will prevent corrosion. It would be nice if you had in mind that the fitting you need on the side of the tank that connects to the expansion tank is a 34 female fitting. On the other side, your copper pipe or size PEX is 12 inches in diameter. You can proceed with mounting the expansion tank bracket if you so want. Before you can attach the expansion tank, you must first complete the mounting process.

You’ll need it at some time if you need to make adjustments to the pressure.

Examples of this include: Attempt to get the pressure as near to the 50-point mark as feasible.

Turn Off the Water Supply and Mount the Tank

The water supply to your home should be turned off at this point. It is preferable to open the lowest faucet to allow water pressure to be released from the water pipes. Afterwards, you may switch off the water heater and secure your expansion tank to the tank bracket with screws.

Add a Tee-Fitting

Holding or placing a towel underneath the spot at which you will put a tee-fitting into the cold water line of the hot water tank is recommended. You’ll see some remaining water there, which will eventually leak. Once you’ve determined where you want to install the tee-fitting, you may cut your supply line. Make use of the tee-fitting to estimate how much of the line you will need to trim in order for the tee to fit. If you run your PEX in a particular manner, it is possible to bend it so that you do not have to cut away any sections at all.

The tee-fitting must be inserted in such a manner that the connection attaching to your expansion tank is facing in the direction indicated by the arrow.

Connect the Expansion Tank to the Tee

Remove the tee fitting and the expansion tank from the pipe and cut a piece of Pex to run between them. Any more fittings between these two will necessitate the cutting of many pieces of PEX to connect them as well.

Quality Control Test

Once you have connected all of the fittings and the whole connection between the cold water supply and the tank is operational, you can begin testing for leaks to ensure that there are none. Those faucets that you opened in order to drain the water and pressure should still be open at this time. After that, you may turn on the valve that connects your house to the main water supply. As soon as you notice a constant stream of water coming out of the faucet, turn it off. Verify that none of the fittings that you fitted have leaks by checking them all.

Leaking joints will need extra pressing or crimping in order to achieve a better joint. Once you’re certain that the connection has been repaired, repeat the turn-on procedure.

Hot water

Finally, turn on the hot water tank again. Have a question or need more information about water heater expansion tanks? Take a look at the video below from YouTube.

Why is the Expansion Tank on the Cold Water Side?

As previously stated, the water heater expansion tank is installed on the cold water side of the water distribution system, as shown in the diagram above. Due to the lack of insulation, this can be linked to the fact that the tank is not sealed. When the increased water volumes reach the tank, they will chill since they will be closer to the cold water source. Therefore, the enlarged water flows through a cold water filter before exiting via the taps and into the environment

Should My Expansion Tank Be Hot?

A frequently asked topic is whether or not the water heater expansion tank should be kept at a high temperature. Unfortunately, the answer is a categorical “no.” When the tank is filled, the top area should be warm while the bottom section should be at room temperature. If the water in the tank is warm throughout, there is a good likelihood that the water in the tank is filled with hot water. The condition is only feasible when the diaphragm fails to function properly.

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It is now evident that the installation of the expansion tank entails splicing into a cold water pipe located above the hot water heater. A tiny air-filled tank is linked to the system, which serves as an expansion chamber, limiting any increase in the amount of water. Because this is a safety device put on water heating systems to safeguard fixtures and pipelines, you must adhere to any applicable plumbing codes that may be in effect at the time of installation. DISCLAIMER: The information provided on HomeInspectionInsider.com is not intended to be professional guidance.

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How to Install an Expansion Tank in Your Plumbing

Tom Lohr is a dedicated home renovation enthusiast who enjoys working on his own projects. Rather of saving money, he likes to use it to purchase new equipment and gardening materials. This is an example of a standard expansion tank. Tom Lohr is a professional photographer.

Prevent Over-Pressurization

Keep the burden off of yourself and your plumbing systems. Excessive water pressure can cause plumbing to become overworked, resulting in costly and harmful leaks. One would assume that the water pressure in your home’s plumbing system would be continuous, but this is not the case. You must have an expansion tank connected to your water supply piping in order to maintain the pressure consistent and prevent over-pressurization. The pressure varies. The optimal water pressure for a residence is around 60 PSI.

  • When I initially examined the pressure in my city-supplied system when I purchased a vacant house, it was 125 pounds per square inch.
  • The water was still running when I switched it back on, and one of the PEX fittings was spouting water.
  • There isn’t much you can do about the water pressure that is delivered to your home or business.
  • Furthermore, if your pressure is high, you should definitely consider installing one.
  • They are very simple to put together, making it an excellent do-it-yourself project.
  • Simply connect it to the water supply and check the pressure.
  • If you do decide to install a pressure regulator, it would be a good idea to do so at the same time that you install a pressure gauge in your water supply line, which should be installed in line with your plumbing immediately after the pressure regulator.

Pressure gauges for PEX systems are rather affordable, and they will keep you informed about the water pressure in your plumbing system.

This is due to the fact that water expands as it warms in your hot water tank.

This was never an issue in the past.

Your home’s plumbing system was completely isolated from the city’s plumbing system, and that valve was the only item that separated the two.

Someone had the bright notion that it was possibly harmful for your home’s water to back up into the city’s water supply system.

If your pipes were tainted, the contamination might spread throughout the city and contaminate others.

Backflow preventers, which are tiny check valves that only allow water to flow in one direction, were required to be installed in residences as a result of this judgment.

The difficulty is that these backflow preventers also prevent the extra pressure in your system from being released by expanding into the city’s system, which would otherwise occur.

The answer is to incorporate an expansion tank. Installing a water pressure gauge is simple thanks to the use of PEX push connectors. Tom Lohr is a professional photographer.

Expansion Tanks Demystified

You’ve undoubtedly come across an expansion tank while working on a plumbing project. Essentially, it is a basic, compact tank that is often located slightly above the water heater and is connected to the main system through a branch pipe. If you don’t already have one, you should get one. It is simple to install, and the total cost for everything is just $70. Showering and using 10 gallons of hot water in a normal 40-gallon hot water heater tank means that you will need to replace 25% of the heater’s capacity.

  1. When cold water is heated, it creates a challenge for the system.
  2. Because of the backflow preventer, the excess volume has nowhere to go and is exerting a significant amount of pressure on your plumbing system.
  3. An expansion tank is a small tank that is divided into two chambers on the inside by a divider.
  4. One side of the expansion tank is linked to the cold water supply to your water heater, while the other side is not attached.
  5. There is a little valve on the end of the tank, similar to the one that is found on a bicycle tire, that allows you to pump the chamber to the exact pressure that you require in your system.
  6. A branch line connects your water heater’s expansion tank to your cold water heater’s expansion tank when the cold water being heated by your water heater expands.
  7. When the pressure in your home surpasses the pressure in the air chamber side of the expansion tank, the water pressure on the other side of the tank bends the rubber wall, providing additional space for your system.
  8. Installing an expansion tank is a worthwhile investment of your time and money due to the peace of mind it brings you.

1. Make a Plan

You should have a strategy in place for how you are going to run a branch line from your hot water tank’s cold water supply to the expansion tank at this time. Create a schematic and gather the fittings you’ll need to connect a line from the expansion tank to a tee-fitting that will be inserted into your cold water supply line, as shown in the illustration. The shirt fitting and the fitting for the end of the tank may be all that is required, if you are fortunate.

Typically, one or more elbow fittings are used in conjunction with the pipe. Less is more in this case. Believe me when I say that this setup makes sense. Tom Lohr is a professional photographer.

2. Choose Your Spot

It will be much easier to do this job if you already have PEX lines in your home. With copper lines, the process is a little more difficult but not insurmountably difficult. It is necessary to first choose the location where your expansion tank will be housed and mounted. It should be installed as near to the water heater as feasible, and at least 18 inches above the water heater itself. Possibly, you’ve seen some that were attached to a copper pipe that was sticking straight up in the air. This method is effective, but it is not encouraged.

Get a universal expansion tank mount instead of going through the bother of modifying your vehicle.

3. Acquire the Necessary Hardware

Additional supplies, such as fittings to connect your tank to the appropriate size water pipes in your home, teflon tape to ensure a secure connection, and at least a few fittings will be required in addition to your tank and bracket. Using PEX push-to-connect fittings will be demonstrated in depth. If you have copper pipes, you can do one of two things: either purchase all copper fittings and learn to braze them on (which is not a difficult skill to acquire), or purchase PEX push to fit fittings, which will connect to both copper and PEX pipes.

If you have galvanized steel pipes, you should carefully consider replacing them.

4. Prepare Tank and Mount Bracket

Make the work simpler by connecting the connection fitting to the end of the tank first, then wrapping teflon tape across the threads of the connection fitting. In order to connect to your tank, you’ll need a fitting with a 3/4 female on one side and your desired size of PEX or copper pipe on the other; often 12 inch. Install the bracket for the expansion tank. Before you can attach the tank, you must first mount the tank. Note: Make sure that the air valve on the other end of the water connection is easily accessible and that there is enough space to accommodate a bicycle pump.

If your water pressure is greater or lower than 50 PSI, pump up the tank or release pressure to get the pressure to the same level as your system.

Before attaching the tank, check the pressure and make any necessary adjustments.

It is functional, but a specialized bracket is more attractive and performs better.

5. Water Supply and Tank

Turn off the water supply to your residence.

Open the faucets at the bottom of the water line to allow the pressure and water to drain out of the water pipes. Turn off the water heater in your home. Attach the expansion tank to the tank bracket using screws.

6. Add a Tee-Fitting

Place or hold a cloth precisely below the point at which you will be inserting a tee-fitting into the cold water supply line of your hot water heater. There will be some leftover water in the pipes, and it will seep out eventually. Cut the supply line at the place where you wish to install the tee-fitting to prevent it from bursting. Make use of the tee-fitting to determine how much of the line you will need to take away to make the tee fit. It won’t amount to much. Depending on how your PEX is laid out, you may be able to bend it sufficiently so that you do not need to take off a portion at all, but only a cut in the line instead.

Make a note of the direction the line between the tee-fitting and the expansion tank will be running in.

Push, crimp, or one of the other two connections on the tee-fitting will suffice.

It was necessary to use an elbow fitting to finish the connection.

7. Connect Tank to Tee

To connect the expansion tank to the tee-fitting that you installed in the hot water tank’s cold water supply line, cut a length of PEX to suit the space. Other fittings between the two will necessitate the cutting of additional PEX sections to join them as well.

8. Do a Quality Control Test

Following the completion of your connections and the establishment of a full line between the tank and the cold water supply, it is time to conduct a leak detection test. Ensure that the faucets that you opened to drain away pressure and water are still operational. Taking it slow, slowly open the valve that connects your home to the city’s water distribution system. If you see that a constant stream of water is flowing out of the faucets, turn them all off immediately. Check for leaks in all of the fittings that you previously placed.

The leaky one will require additional pressing in order to get a better connection, or crimping if you are using that sort of PEX fitting, or brazing if you are using copper pipe.

9. Restart the Hot Water

Restart the hot water tank if necessary.

Pressure Matters

This is a simple Do It Yourself project. The bracket and tank installation will be the most difficult part of the project. It seems like there is never enough space to make things simple. If you have, or if you were smart enough to install, a pressure gauge, make sure the pressure in the expansion tank matches the pressure you set in the expansion tank before. Expansion tanks are rarely given the attention they deserve. As a result of the changing pressure in your water pipes, fittings will get loose and you may ultimately have a leak.

  1. Even if you don’t have a plan for this weekend, you now know what to do next weekend.
  2. Content is provided solely for informative and entertainment reasons and should not be relied upon as a substitute for personal counsel or professional guidance in commercial, financial, legal, or technical problems, unless otherwise specified.
  3. Your posts are chock-full of excellent suggestions for individuals who like to handle things themselves.
  4. It has certainly piqued my interest, and I’m considering testing my water pressure.

The only time I’ve done this is when there is a problem with the heating system, which has been the case thus far.” On January 10, 2021, Umesh Chandra Bhatt, from Kharghar, Navi Mumbai, India, posted the following: Very well done. Excellently described.

Drake Mechanical

What is the purpose of a little circular tank located above your water heater in your home, and have you ever wondered what it is for? The purpose of that tank is very straightforward; it is used to expand the amount of hot water available. In order to prevent water from expanding back into the street while your water heater heats up the cold water, new water meters that are being installed in cities are often equipped with check valves that prevent the water from expanding back into the street.

After installing a check valve or back flow preventer on the incoming water line, it is required by code that we install an expansion tank to keep the water flowing.

See also:  How Often Drain Water Heater

The expansion tank on the water heater serves two purposes: first, it absorbs expansion as the water heats because there is nowhere else for it to go unless a faucet is open, and second, it prevents the T P valve on the water heater from dripping and wearing out before its lifespan because it is the only place for the expansion to go.

If the bladder ruptures or the tank loses its ability to hold air, the device will not function at all.

Whatever is causing it to drip has to be looked at since that valve is a safety valve that prevents the water heater from potentially bursting and hurting you and your family.

Water Heater Expansion Tank Products That We Regularly Stock and Install

The ST-5 is a water heater expansion tank that can accommodate water heaters with capacities up to 40 gallons.

Therm-X-Trol ST-12

An expansion tank for water heaters up to 75 gallons in capacity, the St-12 is designed for use with these units.

Therm-X-Trol ST-25

The ST-25 is a water heater expansion tank that is designed to work with water heaters up to 120 gallons in storage capacity.

Water Heaters That Require an Expansion Tank

  • Tank-type water heaters are more likely to require an expansion tank than other types. On any tank type water heater installation or replacement in the Treasure Valley, the installation of an expansion tank is mandated by code in most sections of the Treasure Valley. Hybrid water heaters are also not considered tankless and are required to include an expansion tank by code in the majority of places. The use of tankless water heaters is not required by code, however there are a few towns, such as Meridian, that will need the use of an expansion tank in order to receive a final inspection. Portable water heaters that are equipped with a check valve in the water supply to the mobile home or on the incoming water supply line to the mobile home

* 24/7/365 Emergency Service For All Of Your Boise, Meridian, and Nampa Plumbing, Drain Cleaning, Water Heater, and Heating and Air Conditioning Needs

  • Boise, Meridian, Eagle, Kuna, Star, Middleton, Marsing, Mountain Home, Nyssa, Ontario, Idaho City, Garden Valley, Notus, and Parma are all places in Idaho.

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. You acknowledge that you are entirely responsible for your access to, use of, and reliance on any information given on this website.

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?

Having an expansion tank built on your home’s water supply line is usually suggested if you have a ‘closed-loop system,’ which can be created by any type of check valve or pressure regulating valve that has been installed on your water supply line. High water pressure in your house is sometimes compared to having high blood pressure, as seen in the following graphic. In most cases, it has no immediate detrimental implications on the person’s life. The long-term wear and tear caused by this excessive pressure, on the other hand, might shorten the life expectancy of everything in your plumbing system.

  1. When subjected to high water pressure, these components are significantly more prone to break prematurely.
  2. The pressure lowering valve is responsible for this (PRV).
  3. The persistent fluctuation of high pressure generated by thermal expansion in a closed-loop system is protected against by this device.
  4. For example, in the city of Frisco, Texas, a PRV and an expansion tank are presently required on any new construction.

This is due to the fact that the water meters are equipped with check valves, which allow for the creation of a closed-loop system. Consult with your city’s plumbing inspector to ensure that you are following all of the necessary plumbing codes in your community.

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. Turn on an outside water faucet with a hose connection and allow it to flow for approximately 15 seconds before turning it off. This will alleviate any potential extra pressure caused by thermal expansion and leaving you with only the pressure that your PRV is set at, as a result. In order to ascertain the water pressure that is currently present on your system, connect your water pressure gauge to the faucet in question. Close the main shut-off valve to your home and turn off the water supply. Activate a faucet and allow all of the pressure to drain out of your system
  2. Head over to the water heater’s expansion tank and connect the pump’s outlet to the Schrader valve
  3. It will be shown by the indicator on your pump how much air pressure is present in the tank. Most manufacturers specify that the pre-charge of their tanks should be set to the same pressure as the previous water pressure reading you took in step 2
  4. However, other manufacturers specify a different pressure. If the pre-charge of your tank does not correspond to the incoming water pressure, you can modify it with your pump to the correct P.S.I. level. It is possible to re-establish the water supply to your home after unplugging your pump and double-checking for leaks

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?

Here at Legacy Plumbing, each and every one of our service professionals has received extensive training in the diagnosis and proper installation of expansion tanks. Any issues or concerns concerning your expansion tank and its installation may be addressed by contacting us, and we’ll do everything possible to assist you.

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