What Size Expansion Tank For Tankless Water Heater?

Are Thermal Expansion Tanks Needed With Tankless Water Heaters?

The use of thermal expansion tanks is often associated with the installation of storage water heaters; however, are they required with tankless water heaters? This is a problem that is commonly neglected. Let’s have a look at the details.

Code Requirements

In accordance with Section 607.3 of the 2012 International Plumbing Code (IPC), the criteria for managing pressure generated by thermal expansion are outlined.There is no clear distinction made between thermal expansion caused by a storage water heater, a tankless water heater, or other system equipment under the provisions of paragraphs 607.3 and 607.3.1.

According to paragraph 607.3.2, a mechanism for managing pressure is required ″where a backflow prevention device, check valve, or other device is installed on the water supply system that is employing stored water heating equipment, such that thermal expansion creates a rise in pressure.″ The International Plumbing Code (IPC) does not specify that a thermal expansion tank be built with tankless water heaters.It is necessary, however, to offer a mechanism of limiting thermal expansion if, as is sometimes the case with recirculation, a storage tank is utilized in combination with a tankless water heater in a closed system.According to the 2012 IPC Code Commentary, the following is a comprehensive explanation: It is important to note that only ″storage water heating equipment″ is designated as the hot water generator in this section (607.3.2).While this appears to indicate that thermal expansion-induced pressure rises are solely experienced by water heaters in storage tanks, this is not the case at all.

When it comes to water distribution systems with tankless water heaters, one of the most commonly asked questions is ″Does a water distribution system with tankless water heater require management of pressure increases induced by thermal expansion?″ The following two examples demonstrate how to find the solution.A water distribution system with a tankless, on-demand water heater (electric or gas) that does not require a storage tank is referred to as System 1.The water in this system is only heated when a hot water outlet is turned on or off.In addition, because the water distribution system has been converted to a ″open″ system (i.e., a hot water outlet has been opened), all thermal expansion is dissipated through the open hot water outlet, and no pressure rise is possible.As soon as the outlet is shut off, the system is considered to be closed; nevertheless, because the flow has been stopped, the tankless water heater ceases to heat the water.

Because of this, there is no need for techniques of managing pressure increases caused by thermal expansion of air.System B: A water distribution system with a tankless, on-demand water heater (electric or gas) and a storage tank is used in conjunction with a tankless water heater.A backflow preventer is installed in the water service line (such as a dual check valve at the water meter).This system may necessitate the installation of an unfired hot water storage tank in order to facilitate hot water recirculation and reduce the ″wait time″ for hot water to reach any fixture.Alternatively, the storage tank may be necessary to meet the demands of a big number of people at the same time (that the tankless water heater cannot produce without the storage).Due to either of these reasons, when the hot water storage tank cools, a circulation pump is activated, causing water to flow out of it and back into it through the tankless water heater until it reaches a temperature that is suitable for drinking or bathing.

  1. There will be periods when no hot water outlet is opened during the time that the tankless water heater is heating water, resulting in a ″closed″ system for the water distribution system.
  2. As a result, a mechanism of limiting pressure rises due to thermal expansion must be supplied.
  3. Please keep in mind that if there is a check valve, pressure regulator, or backflow preventer placed in the main supply line, thermal expansion tanks are required by the Uniform Plumbing Code, regardless of the kind of water heater used.
  4. As a result, it is necessary to assess if a thermal expansion tank is required based on the municipal code that has been implemented.

Closed Systems – Recirculation

When a closed system with a heating source is present, there is the possibility of pressure rises as a result of thermal expansion.Tankless water heaters that are fitted with a recirculation loop and a storage tank are an example of this type of installation.To prevent the possibility for pressure buildup, it is necessary to create a device such as a thermal expansion tank to contain the situation.

Take note that the pressure relief valve on a water heater cannot be utilized as the device to regulate the water pressure.

Buffer Tanks

Tankless water heaters with incorporated buffer tanks are becoming more common in newer versions.Although these tanks are tiny (1–2 gallons), the thermal expansion of the water in them can result in a significant increase in system pressure.Unless a tankless heater is equipped with an internal buffer tank, a thermal expansion tank should be incorporated into the system design to prevent overpressurization.

Are there any other cases that you have come across where thermal expansion tanks were required in conjunction with tankless water heaters?Make a suggestion for a blog article that you would like to see published.

Tankless Water Heater Setups that Require Expansion Tanks

Tankless water heaters are becoming increasingly popular for a variety of reasons, including their ability to provide on-demand hot water and their compact form.Even though many tank-style water heaters are equipped with thermal expansion tanks, you may be asking whether an expansion tank is necessary with a tankless water heater.Is it necessary to have a thermal expansion tank with a tankless water heater?

No.According to Section 608.3 of the 2018 International Plumbing Code (IPC), tankless water heaters are not required to include a thermal expansion tank if no water storage device is being utilized.There are, however, a few notable exceptions.It is necessary to employ an expansion tank when using a tankless water heater in conjunction with another kind of water heater or recirculating system that makes use of an external storage tank in a closed plumbing system in order to manage thermal expansion.

A tankless water heater system does not fall within this category, and therefore does not apply to most homes.Do you require the services of a Licensed Plumber?We can assist you!In your location, you may get a free estimate from plumbers that are top-rated, vetted, and licensed.In conjunction with water heaters, a thermal expansion tank serves as a safety measure that helps to minimize the possibility of pressure damage to your plumbing system.

There are occasions when a thermal expansion tank is required, and there are instances when it is not!Most tank water heater systems now require expansion tanks to aid in the regulation of pressure within the water heater, which is especially important in municipal water supply plumbing system installations.If the home has a closed plumbing supply, this means that there is a check valve or backflow preventer in place that prevents the release of water pressure that has built up in the house from flowing back into the water supply line.Thermal energy is used to generate pressure in a plumbing system’s water supply lines.When water is heated in a storage tank, it turns into vapor, which raises the pressure in the plumbing pipes and causes them to burst.It is possible for your tank-style water heater to explode if there is no place for the pressure to release during thermal expansion.

Expansion Tanks and Tankless Water Heaters

Due to the fact that hot water is generated on demand, tankless water heaters do not store hot water.In other words, when you turn on the hot water tap, the water heater heats the water so that it may flow to the hot water tap.When the water faucet is closed, the water heater ceases to produce warm water.

The majority of tankless water heaters (whether electric or gas) do not require the use of a thermal expansion tank.The reason for this is that a tankless water heater only generates hot water when it is needed to do so.The tankless unit begins to produce hot water as soon as the hot water supply is turned on and turned off.Because of this, an open plumbing system is created that does not require the use of a thermal expansion tank to regulate thermal expansion.

By turning off the hot water faucet, you are effectively shutting off the plumbing system.However, because the tankless unit ceases generating hot water, there is no need for a thermal expansion tank to keep thermal expansion under control.According to the building code, expansion tanks are not necessary for tankless water heaters that do not have a hot water storage tank installed.Typically, they are employed as a preventative measure to extend the life of your water heater and lessen the possibility of your plumbing system becoming ‘overworked.’ Let’s break this down even more with the help of two examples: Some tankless water heaters will require the addition of a thermal expansion tank in certain circumstances.It is possible to locate a tankless water heater used in conjunction with a tank-style water heater in large residences where there is a great demand for hot water.

Tankless Water Heaters with Recirculation System

The supply pipe of certain tankless water heater systems is fitted with a recirculating system, which circulates hot water through the supply piping on a regular basis to prevent hot water in the supply piping from turning cold.There is usually a storage tank or a supplementary water heater included in these systems.If you have a closed plumbing system, you will almost always need a thermal expansion tank in these situations.

Having established the fact that the need of a thermal expansion tank for a tankless water heater is only necessary in more complex installations using a closed piping system, we may proceed to examine the subject further in greater depth below.An expansion tank will be discussed, as well as where it should be placed.We’ll also go over the advantages of having an expansion tank as well as how to properly test one of them.These situations typically occur when a tank-style water heater is the primary hot water source, with the tankless water heater acting as a backup on-demand system to deliver continuous hot water even when the tank water heater runs out of hot water and enters recovery mode.

In that case, if you’re interested in learning more about tankless water heaters and expansion tanks, then let’s get started!

Why Do You Need an Expansion Tank on a Water Heater?

The International Plumbing Code (IPC) specifies that a thermal expansion tank is necessary in cities where residential plumbing systems are closed.When a check valve or backflow preventer is put on your main water line, you may need to install a thermal expansion tank to prevent the water from backflowing into your home.Essentially, this unit serves as a backup device to avoid excessive pressure build-up, which may lead to potentially major (and expensive) plumbing difficulties over time.

Water from the heater is sent into the expansion tank, which lowers the pressure to a safe and manageable level.

Water Distribution System Using a Tankless Heater (Electric or Gas) Without a Storage Unit

When using a tankless water heater, hot water is created only when it is required, which is referred to as on-demand heating.On-demand does not necessarily imply instantaneous service since the chilled water in the hot water piping must be released and the hot water created must travel through the plumbing system to reach the open tap before the service can be completed.According on the distance between the fixture and the tankless water heater, this process normally takes around 2-3 minutes to complete.

The water is only heated when the hot water tap is turned on.There is no thermal expansion since the tankless water heater does not create and store hot water in a storage tank, hence reducing the amount of thermal pressure that is placed on the plumbing system.

Water Distribution System Using a Tankless Heater (Electric or Gas) With a Storage Unit

As previously noted, a tankless water heater that uses a recirculation pump in conjunction with a storage tank or water heater will require a thermal expansion tank in order to regulate thermal expansion within the plumbing system.In this setup, an unfired tankless water heater may be required to recirculate water in order to reduce wait times or prepare for high hot water demand during periods of peak demand.When a storage unit cools down, a circulation pump is activated, allowing water to flow from the tank, through the water heater, and back into the storage unit until the water reaches the required temperature level for the storage unit.

Due to the fact that this occurs when the water outlet is blocked, the plumbing distribution system is effectively ‘closed’ at this point.As a result, a thermal expansion tank is necessary in order to regulate the water pressure induced by thermal expansion.Regardless matter how it is installed, a tankless water heater requires regular maintenance.See our post, Easy Maintenance Tips for Tankless Water Heaters with Photographs, for more information.

This step-by-step tutorial will assist you in keeping your system in peak operating condition.

Are Expansion Tanks Required by Code?

According to the International Plumbing Code (IPC), any water heater systems (even tankless types) in which thermal expansion might possibly create a harmful surge in pressure must be equipped with expansion tanks, which became necessary in 2012.Homes with closed plumbing systems that have a backflow prevention device or a check valve installed are exempt from having to comply with this requirement.As plumbing systems and components continue to change, there have been and will continue to be several modifications to the manual.

What are the Benefits of a Thermal Expansion Tank?

A thermal expansion tank is a device that is used to regulate and lower the amount of water pressure in a plumbing system.When water pressure is too high, it can damage plumbing valves, weaken supply pipe couplings, and limit the life of your water heater, which can cause it to fail prematurely.These flaws not only cause difficulties in your house, but they are also quite expensive to address.

Thermal expansion tanks are an additional expense up front, but they may save you money in the long term if you use them properly.They lower the likelihood of significant and expensive plumbing issues as a consequence of uncontrolled water pressure and ensure that your water heater continues to operate properly for years, if not a lifetime!

See also:  What Is The Quietest Rv Water Pump?


In recent years, water heater manufacturers have attempted to resolve the ever-confusing issue of instant hot water vs continuous hot water by developing more efficient models.Many modern tankless water heaters are equipped with a recirculation mechanism that is incorporated into the unit.Because these systems only produce a limited volume of hot water when the system is closed, I anticipate that the building code for tankless water heaters and expansion tanks will be revised in the future years to reflect this.

More information on the lifespan of a tankless water heater can be found in our article How Long Does a Tankless Water Heater Last?(click here).DISCLAIMER: The information provided on HomeInspectionInsider.com is not intended to be professional guidance.Before beginning any job, you should contact with a competent expert and verify that all necessary permits have been obtained.

It is owned and operated by Hubert Miles who is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by placing advertisements and links on their websites that direct traffic to Amazon.com (hereinafter referred to as ″Amazon.com″ or ″Amazon.com Associates Program″).As an affiliate, HomeInspectionInsider.com participates in a variety of affiliate programs with other websites.Hubert Miles receives a commission for recommending visitors and commerce to these businesses.

Expansion tank sizing for tankless heater?

You should post this in the ″design dilemma″ area of the discussion board.Currently, I have three Noritz gas tankless hot water heaters, and I am really pleased with them.However, I understand why some people may be apprehensive of tankless hot water heaters.

1.Tankless hot water heaters are more energy efficient than traditional tank-style water heaters.reducing overall operating costs 2.Tankless water heaters have the ability to deliver an infinite supply of hot water, which is not possible with tank-style heaters.3.

Tankless heaters are more compact and take up less room than traditional heaters.In addition, they may be mounted outside.4.Unlike tank-style heaters, tankless heaters do not have a tank that will corrode and leak over time.The disadvantages of tankless heaters are as follows: 1.

They are more expensive up front.2.Not all installers / plumbers are familiar with the installation of a tankless water heater.Only hire an installer who has been certified by the manufacturer of the product you intend to purchase.Installation expenses are greater as well, because stainless steel ducts for venting tankless heaters (interior installation) are more expensive, and a tankless heater may need the installation of a bigger gas line.4.

  1. The possibility of a lag period in the flow of hot water.
  2. If you decide on a tankless system, I would recommend installing it outdoors to save installation costs and make future maintenance easier.
  3. It’s been eight years since I placed two tankless heaters outside, and I haven’t done anything to them.
  4. I have another tankless water heater that has been in use in a laundry room for five years and just required service a year ago because to lint.

The technician and I were both unaware that the manufacturer advises against placing tankless heaters in laundry rooms until after the installation was completed.My previous experience with tankless heaters has only been with natural gas models; I have no experience with electric models.I’ve owned both electric and gas heaters with tanks throughout the years.A recirculation pump may be necessary to deal with the lag time between hot water supply and consumption.It would reduce the efficiency attained by a tankless heater, but it would reduce the amount of water used in the process.Another alternative is to install multiple tankless water heaters in order to reduce the distance between the hot water output and the heaters.

For example, if your kitchen sink is located far away from the heater, you can consider installing a small electric tankless heater for it.It is customary to locate a bigger tankless heater nearer to the bathrooms, where a higher output of hot water is required and a shorter lag time between output and demand is preferable.In addition, your contractor must ensure that the plumber builds the shortest feasible runs from the tankless to the outputs of the system.More information may be found here.

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.Taken into consideration that 50 gallons of cold water will, with the assistance of thermal expansion, become a minimum of 52 gallons once it has been heated, the additional 2 gallons of water will not fit in the water heater’s tank.

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.

Your water pipes, water heater, and even certain appliances must deal with the increased pressure induced by thermal expansion if the necessary check valves and backflow preventers are in place.Consequently, there is an increase in needless wear and strain, which can lead to damage to hot water-using equipment, including your water heater.A bursting pipe might possibly be the result of this condition!An expansion tank for a Watts DET-5 water heater.

The Watts DET-5 is the ideal size for water heaters up to 50 gallons in capacity.

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.In contrast, instead of letting the pressure to build up, the extra water is sent into the expansion tank instead.

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.This helps to conserve energy.Water that has overflowed into the expansion tank is disposed of in the waste tank.It is not capable of storing water on a long-term basis.

Watch the Video

Why Do I Need an Expansion Tank?

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.As you might expect, excess hot water can also seep out via the T&P Valve, causing significant water damage to surrounding areas.Even if no components fail completely and no leaks arise, failing to install an expansion tank might have detrimental implications in some cases.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: A water heater’s capacity may be discovered on the factory label that is connected to the water heater.
  • Household Water Pressure – A water pressure gauge may be used to monitor the water pressure in your home’s plumbing, which is measured in psi (pounds per square inch). Simply connect the gauge to a hose or faucet and turn on the water to test the pressure. It is recommended that you monitor your water pressure during a 24-hour period of time. Another alternative is to get in touch with your local water provider.

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

This chart will guide you through the process of selecting the correct size expansion tank for your household water heater. It is presumptively set as 150 degrees Fahrenheit in this case.

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

For water heaters that do not meet these static supply pressure readings or capabilities, it is essential to consult with a qualified plumber or 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 might 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 sure the expansion tank has enough air pressure by measuring it using a tire gauge.
  • The air pressure in the expansion tank should be adjusted to meet the maximum water pressure in the home. Rather than an air compressor, a hand pump is used.
  • 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.

Watch the Video

How to Maintain an Expansion Tank

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.Providing that it is properly placed, a thermal expansion tank has an average lifespan of six years on average.

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: Turn off the water supply to your home and open a faucet to reduce the pressure created
  • Attach a tire pressure gauge to the valve stem of the expansion tank after removing the cap from the valve stem. The pressure should be greater than 75 pounds per square inch.
  • If there is no air pressure within the tank, this indicates that the expansion tank is not working properly. The old one will have to be replaced with a new one.
  • If there is pressure within the tank, you will need to check the water pressure
  • otherwise, you will need to replace the tank.
  • The water pressure in the expansion tank and the water pressure in the reservoir should be comparable. It will be necessary to use a hand pump to supply air to the expansion tank if your tank is not equivalent.

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.It may be necessary to use a tire pump to inflate the tires if the pressure is too low.When adding air, we strongly advise against using an air compressor and instead utilizing a hand pump.

Using an air compressor to squeeze the bladder might cause it to burst.

Watch the Video

Published on March 4, 2022 / Affiliate links included / Images from the Amazon Product Advertising API

Water Heater Expansion Tank

Water expands when it is heated and, if it doesn’t have any place to go, this can create a dangerous situation.

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.It is intended to deal with the extra water that accumulates over time.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 your water expands due to thermal expansion, a water heater expansion tank minimizes unwelcome increases in pressure.When water is heated from 50 degrees Fahrenheit to 120 degrees Fahrenheit, it expands by approximately 2 percent.Install the expansion tank further down the line from the intake valve that supplies hot water to the rest of your house.The tank is divided into two portions by a rubber valve.The tank is made of two sections.

Water runs through the top section, and pressured air is contained inside the bottom portion.Due to the presence of this air pressure, the tank is able to absorb the excess pressure generated by your water heater, keeping it away from the rest of your home’s systems.

Share & Save this graphic to refer back to!

Common questions about water heater expansion tanks include:

What is a check valve?

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

Initial steps include drilling a tiny hole into the existing pipe.The clamp is next tightened such that the hole in the clamp coincides with the entrance 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 put in one direction (vertical).

Instead, we recommend that you solder the necessary fittings into the system or that you use galvanized fittings to protect the system.

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.

If you have a tankless water heater, you won’t require an expansion tank because there is no tank and hence no buildup of pressure.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.

What Size Expansion Tank Do I Need for a 50 Gallon Water Heater?

Water heater expansion tanks are smaller tanks that are situated above your water heater and serve a critical role in supplying your home with the water it requires to function properly.Because of the differences in size and design of water heaters, different sized expansion tanks are required.As a general rule, the size of the expansion tank corresponds to the size of the water heater.

For a 50-gallon water heater, you’ll need an extension tank that holds 2-gallon of water.However, depending on how strong your water pressure is, you may need to upgrade to a 4.5-gallon expansion tank instead.If you’re looking for an expansion tank, the only things to consider are the size of your water heater and the strength of your water pressure.More information on how to pick an expansion tank and why you need one will be covered in greater depth in this post.

Whatever your location (city or country), water heater expansion tanks may save you both money and time by preventing you from having to replace or repair your water heater.Sale

What Sizes are Expansion Tanks Available in?

Expansion tanks, also known as thermal expansion tanks, are available in two different sizes: 2 gallon and 4.5 gallon.The size that you require is determined by the size of your water heater as well as the pressure of the water that is being delivered to it.Because of this expansion, the water in your water heater warms up faster.

As a result, thermal expansion tanks are used to refer to expansion tanks that have been heated.When water is heated, a gallon of water will expand to a gallon and a half, or 52 gallons in total.As a result, a 2-gallon expansion tank is generally sufficient to accommodate a 50-gallon water heater with ease.When in doubt, however, it is always preferable to increase the size of the expansion tank rather than decrease the size.

Having a tank that is too large is not a problem, but having a tank that is too tiny might be a problem.

How Much Does It Cost to Install an Expansion Tank?

The entire cost of installing a thermal expansion tank often ranges between $250 and $500 dollars.When evaluating overall expenditures, it is important to take into account the cost of the expansion tank itself as well as the time it will take to build it.Most plumbers charge between $70 and $150 per hour, and installation of expansion tanks can take anywhere from 1 to 2 hours, depending on the intricacy of the job.

The tank itself will only cost between $40 to $200, depending on the size of the tank and the brand you want to use.A 4.5-gallon tank will cost more than a 2-gallon tank, and better brands such as A.O.Smith and Amtrol will be more expensive than lower-quality ones.Thermal expansion tanks are similar to most other things in life in that you get what you pay for.

Cheaper tanks will be less expensive to install, but they might end up costing you a lot more money in the long run.Poor-quality expansion tanks are more likely than costly expansion tanks to leak and fail.A faulty expansion tank will need the replacement of the tank much more frequently than is necessary, and it may even result in the failure of the water heater.

When Do I Need an Expansion Tank?

Depending on where you reside and what city or county you live in, expansion tanks for all water heaters may be necessary.Nevertheless, this is not always the case, and expansion tanks are optional in some areas.Aside from being required by law, the most common situation in which an expansion tank is advised is when you have a closed-loop water system installed.

When a closed-loop water system is established on its plumbing system, it is defined as one that has any type of check valve or water pressure regulating valve installed on it.These sorts of valves, on the other hand, are required if the water pressure that comes into your home is between 40 and 80 pounds per square inch.An expansion tank will not reduce the pressure of the water flowing through it, but it is essential to battle the heat buildup that occurs as a result of the use of pressure valves in the system.A closed-loop system is characterized by the accumulation of heat pressure, which has nowhere to go if there isn’t an expansion tank present.

In the case of a water heater that fails due to thermal expansion, it seems as if there has been an explosion on the interior of it, causing the sides to bubble outwards.Thermal expansion tanks provide a safe place for the pressure to escape and prevent this from occurring.Interested in learning the distinction between an expansion tank and a pressure tank?More information may be found in this article.

Can I Have More than One Expansion Tank?

If you have a number of water heaters, each of which requires an expansion tank, you can have one tank for each of the water heaters. A single expansion tank can be linked to numerous water heaters, however it is not recommended to use more than one expansion tank with a single water heater. Individual expansion tanks for each water heater in your home are also an option.

Frequently Asked Questions

What is the life expectancy of an expansion tank?

Your expansion tank’s lifespan is hard to predict with any degree of accuracy.It is possible for some to fail within two years of installation while others might endure for more than a decade.The quality of your expansion tank, as well as the manner in which it was placed, both have an influence on its longevity.

Water quality and other factors have an influence on the longevity of a product.

What are common issues with expansion tanks?

The most frequently seen problem with expansion tanks is their proclivity to leak.If they are not placed properly, or if they are put in the incorrect size, leaks are almost certain and will occur considerably sooner than they should have.Expansion tanks must be erected vertically and with enough support due to the fact that when they fill with water, they become significantly heavier and must be adequately supported.

Does an expansion tank affect your water pressure?

However, while water pressure has an impact on your expansion tanks, your tank will have no impact on your water pressure. It is a widespread misperception that having an expansion tank will cause your water pressure to decrease; however, this is not the case.

Can I install an expansion tank myself?

It is possible to install an expansion tank by yourself if you have the proper tools and abilities to complete the work. Installing an expansion tank is made simple with the help of the instructions and directions that come with each tank.

Is it OK to oversize a thermal expansion tank?

It is absolutely OK to oversize a thermal expansion tank; however, you must ensure that the tank is not undersized. A tank that is overly large will merely cost a little more money to acquire, but it will cause no harm in the long run. When it comes to tank sizes, it’s usually best to go with a larger tank rather than one that is too little for your needs.

Should the expansion tank be installed on the hot or cold side of my water system?

While there are few cases in which it is OK to put an expansion tank on the hot water side, it is always preferable to place them on the cold side whenever at all possible.

How do I size a water heater expansion tank?

Step-by-step instructions on how to size a water heater expansion tank are provided below.

  1. Visit a website that offers an online expansion tank calculator.
  2. You must enter the water pressure that is used to supply your home.
  3. Fill in the blanks with the gallon capacity of your water heater.
  4. If you have a pressure relief valve on your water supply line, enter the setting for it.
  5. Calculate the smallest possible expansion tank size and, if necessary, increase it by one size.

Nick Lopresti is the creator of YourH2Home and a well-known specialist in the field of home renovation. He has years of expertise writing on a wide range of home improvement issues, the most of which are related to plumbing and water systems.

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.Plumbing work should only be performed by a licensed and insured expert.

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.It’s not an issue.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.In this case, a large expansion tank is required.

It absorbs the extra pressure if it is put correctly.One-half of the tank is filled with water drawn from your home’s main water supply system.The remaining half of the container is filled with compressed air.In the centre of the bladder is a butyl rubber bladder.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.The toilet fill valves, the supply lines, and the solenoid valves found in washing machines, dishwashers, and ice makers are often the weakest sections of the system, according to the manufacturer.When subjected to high water pressure, these components are significantly more prone to break prematurely.The installation of an expansion tank alone will not correct excessive pressure over 80 PSI delivered to your property by the city water supply.

The pressure lowering valve is responsible for this (PRV).When the pressure in your house is between 40 and 80 pounds per square inch (psi) and you have a pressure relief valve (PRV) or a check valve, the thermal expansion tank comes into play.The persistent fluctuation of high pressure generated by thermal expansion in a closed-loop system is protected against by this device.The installation of an expansion tank may be necessary by the city, depending on where you reside in North Dallas, regardless of whether or not you have good water pressure, in order to pass plumbing inspections, such as those required when installing a new water heater.For example, in the city of Frisco, Texas, a PRV and expansion tank are presently required on all new construction residences.

Additionally, as of the time of this writing, an expansion tank is needed on all new and replacement water heaters in Little Elm, TX, regardless of size.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.Tanks erected in this region are often covered by a one- or five-year guarantee, which means that they should be replaced every two to six years.

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.When the tank is installed, a qualified plumber will ensure that it is adequately supported and that the connection is secure.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.

Another thing you can do to increase the lifetime of your thermal expansion solution is to invest in a high-quality tank that comes with a five-year manufacturer’s guarantee.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.Most manufacturers recommend inspecting expansion tanks once a year when they are first installed and more often as the tank ages.

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.As soon as the extra pressure is released, the flow will level out and remain constant.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.Instead of a clank where there is air, it should be more of a hollow ring where there is air.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.
  2. In order to ascertain the water pressure that is currently present on your system, connect your water pressure gauge to the faucet in question.
  3. Close the main shut-off valve to your home and turn off the water supply.
  4. Activate a faucet and allow all of the pressure to drain out of your system
  5. Head over to the water heater’s expansion tank and connect the pump’s outlet to the Schrader valve
  6. 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
  7. however, other manufacturers specify a different pressure.
  8. 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.
  9. It is possible to re-establish the water supply to your home after unplugging your pump and double-checking for leaks

Make sure you have a hose connection to an outdoor water faucet and allow it to flow for about 15 seconds.This will alleviate any potential excess pressure caused by thermal expansion and leave you with only the pressure that your PRV is set to, as a result;
In order to ascertain the water pressure that is now present on your system, connect your water pressure gauge to that faucet;
Close the main shut-off valve to your home and turn off the water.Open a faucet and allow all of the pressure in your system to drain out.

Go to the expansion tank and link the output of your pump up to the Schrader valve; then return to the house.It is possible to detect how much air pressure is in your tank by looking at the gauge on your pump.Most manufacturers specify that the pre-charge of their tanks should be set to the same pressure as the previous water pressure reading you recorded in step 2; however, other manufacturers specify that the pressure should be adjusted to higher pressures.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.

If your pump has been disconnected for any reason, you may reconnect it and double-check for leaks; otherwise, you should call a plumber.

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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