Expansion tanks are not necessarily required for tankless water heaters; however, they can serve an important purpose by helping to regulate water pressure in the system. Expansion tanks are used to avoid an increase in water pressure when the water heater is powered on or when other fixtures in the home are used.
When the pressure in the water heater system increases or decreases, water will be displaced from or added to the tank to compensate. This helps to maintain a predetermined pressure in the system, which will help to prevent damage to pipes and appliances.
In some cases, local building codes may require an expansion tank to be used with a tankless water heater. Consult your local building codes to determine if an expansion tank is required.
What happens if I dont use an expansion tank?
If you don’t use an expansion tank with a closed hydronic heating system or closed water heater, there could be a number of negative consequences. The system could become pressurized and there would be no mechanism to release the pressure.
This could cause a number of problems, such as swelling of pipes and joints, leakages, and catastrophically, an explosion of the system, as the pressure builds up. Additionally, the pressure could cause damage to the system, such as ruptured seals and gaskets, deterioration of joints and connections, and even disrupt the flow of the water, significantly reducing the performance of the system.
Lastly, it could cause damage to the components of the circuit, such as the water heater and boiler. Therefore, it is important to always install an expansion tank when creating closed heating systems or closed water heater systems.
What size expansion tank do I need tankless?
When sizing an expansion tank for a tankless water heater, you will need to consider the following variables:
1. The tankless water heater model that you have: Different models of tankless heaters will require different sizes of expansion tanks.
2. The incoming water pressure that you have: This will determine the maximum pressure that you can safely store in the expansion tank. The higher the water pressure, the larger the expansion tank should be.
3. The volume of water that the tankless water heater will be expected to heat: If the volume of water to be heated is large, then a larger expansion tank will be needed.
4. The temperature of the water that the tankless water heater will be expected to heat: Higher temperatures will require larger expansion tanks.
Once you have all of this information, you can use a water heater expansion tank sizing calculator to determine the exact size of expansion tank you will need for your tankless water heater. The calculator will take the above variables into account and provide you with the best size tank for your water heater setup.
Does a Rheem tankless water heater need an expansion tank?
Yes, a Rheem tankless water heater needs an expansion tank. This is because when the water in the heater reaches its maximum temperature limit, it expands, and if there is no room for it to expand, the pressure can cause problems.
An expansion tank absorbs the excess pressure, acting as a shock absorber for the system and preventing potential issues from arising. When it comes to selecting an expansion tank for a Rheem tankless water heater, it is important to get one that is specifically made for that type of heater.
The size and type of the expansion tank will vary depending on the size and BTU of the Rheem tankless heater, so be sure to refer to the manufacturer’s specifications before making a purchase.
How do I know if I need an expansion tank?
If you have a closed plumbing system, you likely need an expansion tank installed, as they help manage high water pressure in the system and prevent pipeline damage. Expansion tanks are filled with air and accept water that has been heated.
As it expands and takes up the increased volume, it is then pushed back into the system, preventing it from causing a pressure overload. In order for expansion tanks to be effective, they must be properly sized for your system.
To determine if you need an expansion tank and the correct size, you’ll need to know your system’s volume and the level of pressure that it will be expected to withstand. You should also consider the possible effects of pressure changes, including thermal expansion caused by increases in temperature.
Additionally, if your local water supply has high levels of minerals, you may need approval from the local municipality before installing an expansion tank. It’s best to consult with a qualified plumber or heating contractor to ensure that you have the correct size and installation for your system.
When did expansion tanks become code?
Expansion tanks became mandatory in the United States in 2003 due to the American Society of Plumbing Engineers (ASPE) issuing a requirement that “All domestic hot water systems shall be protected from thermal expansion by the installation of an approved expansion tank” (referencing the 2003 edition of the “Uniform Plumbing Code”).
Prior to that, expansion tanks were often recommended to protect closed water heating systems from the damaging effects of thermal expansion. In 1962, the adoption of the first Uniform Plumbing Code (UPC) specifically addressed this issue by requiring the use of some form of expansion device.
In the 2002 edition of the UPC, it became further entrenched with a full section devoted solely to the installation of expansion tanks on closed hot water systems. The 2003 ASPE redesignation made them code requirements when installing hot water systems.
How much does it cost to install an expansion tank?
The cost to install an expansion tank depends on the type of tank, the size of the tank, the difficulty of accessing its location, and the labor involved. A basic expansion tank for residential water heater system costs between $50 to $200.
Larger tanks can cost from $200 to $1,500 or more, depending on the size and type of installation. Other related items such as installation kits, valves, and additional piping may also need to be purchased, which could increase the cost.
Professional installation charges will typically range between $250 and $900, depending on the difficulty of the job.
Where should the expansion tank be installed?
The expansion tank should be installed as close as possible to the water heater, without being directly connected to the water heater. The tank should be mounted vertically and securely anchored to the wall.
It should be installed so that the top of the tank is at least 12 inches above the top of the water heater, and the highest water level in the system is at least 4 inches below the top of the tank. It should not be installed in an area where it is likely to become exposed to extreme temperatures.
This can be achieved by mounting it on the interior side of an exterior wall and/or providing some kind of insulation. Additionally, the tank should be installed in a location that provides easy access for maintenance and inspection.
How long does an expansion tank usually last?
The lifespan of an expansion tank depends on a number of factors, including the quality of the tank, water quality, temperature and pressure variations, and maintenance practices. On average, a quality expansion tank should last 10-15 years under normal operating conditions.
However, that lifespan can be significantly shorter if the tank is subject to frequent water pressure and temperature fluctuations. Furthermore, if the tank is not regularly inspected and maintained, it is likely to experience a shorter lifespan.
Regular maintenance includes filtering out the air inside the tank, replacing the bladder when it shows signs of wear or rupture, and regularly inspecting the tank for any signs of corrosion.
Does an expansion tank go on supply or return side?
The placement of an expansion tank largely depends on the type of closed water system you are using for your hot water heater, and the flow of water within the system. Generally, an expansion tank should be connected to the cold water supply line specifically to the point just before the hot water heater inlet.
The purpose is to make sure that the cold water pressure does not exceed the recommended pressure rating for the hot water heater. If the pressure gets too high, the tank will take in the expanded water, eliminating the need to release it through a pressure relief valve.
When the water pressure is released to the expansion tank, it will come in on the “supply” side. However, the “return” side works the same way; when the pressure is released, it will come out the “return” side.
It is important to ensure that the pressure of the incoming water pressure remains consistent and that the pressure relief valve is functioning properly.
Is an expansion tank really necessary?
An expansion tank is a component in most hot water heating systems that helps to regulate pressure in the system. It helps the system to function properly and last longer. Expansion tanks are important when the system is closed and it helps to control the pressure in the system so that the system does not overpressurize and cause excessive water hammer or other damage.
Expansion tanks also help to manage thermal expansion, which can occur when water is heated. Without an expansion tank, the pressure in the system can become too high and create excess strain on the pipes and other components, causing them to fail prematurely.
Therefore, yes, an expansion tank is really necessary.
Can you install water heater without expansion tank?
No, unfortunately, it is not recommended to install a water heater without an expansion tank. Expansion tanks are an important part of the plumbing system, as they are designed to prevent water pressure inside the water heater from exceeding the pressure capacity of the pipes or fixtures in the plumbing system.
An expansion tank allows water to expand and contract as it is heated, including when it is heated inside the water heater. If a water heater does not have an expansion tank, the increased water pressure can cause leaks or other plumbing system damage.
Expansion tanks also offer protection for fixtures and appliances using a hot water supply, such as bathtubs, showers, and washing machines.
Therefore, it is highly recommended to install a water heater with an expansion tank to ensure that the plumbing system is able to handle the changes in pressure when hot water is present, and to protect fixtures and appliances in the home.
How far away from a water heater can you install an expansion tank?
When installing an expansion tank for a water heater, it is recommended to place it as far away from the heater as possible, preferably on the opposite side of the heater depending on the size of the tank.
This will provide the most stability and minimise the risk of damages to the heated water system components caused by the thermal expansion of water. Generally, the recommended distance is at least 6-8 feet away from the water heater, but this could vary depending the condition of the specific heater and the size of the expansion tank.
Additionally, the expansion tank should be placed in an area of limited temperature variation to ensure the thermal expansion is controlled and the tank functions as intended.
Do I need an expansion tank if I don t have a backflow preventer?
No, you do not need to install an expansion tank if you do not have a backflow preventer. A backflow preventer is designed to prevent contaminated water from entering your water system, while an expansion tank helps regulate pressure inside the system.
Without a backflow preventer, pressure can fluctuate if water is used at multiple points in the system. Expansion tanks are useful for preventing thermal expansion from causing pressure to build up inside the system, as well as helping cushion pressure pumps in the system to extend the life of the pump.
However, if you don’t need the extra pressure protection and cushioned pump, then the expansion tank may not be needed. It is always best to consult with an experienced plumber or engineer before making a decision.