Since water expands when it is heated due to thermal expansion the water heater creates extra water volume every time it heats water.
Electric hot water heater expansion tank.
New or larger expansion tanks may be needed due to pressure reducing valves check valves and backflow preventers added to the community s water system.
The tank has two sections that are separated by a rubber valve.
It is used to absorb excess water pressure.
This ultimately protects it from damage.
What size expansion tank do i need.
You install the expansion tank down the line from the inlet valve that sends hot water into your home.
When an expansion tank is installed the extra water volume automatically rushes into the tank.
The hot water expansion tank is a two gallon tank that hangs off of your hot water system or your boiler.
When water is heated or a hot water faucet is turned off abruptly pressure builds from expanding water molecules.
The expansion tank serves as a backup system to prevent overworking your plumbing.
The excess water volume instead of causing too much pressure on the plumbing rushes into the expansion tank and lowers the pressure in the water heater to safer levels.
Hot water heater tanks are not designed to expand so you need an expansion tank otherwise it may eventually burst.
Water expands by roughly 2 as it heats up from 50 f to 120 f.
Expansion tanks aka thermal expansion tanks are essentially safety devices to help you minimize the risk of damage to your hot water tank they are an add on to your existing hot water heater and are often installed on the water supply pipe to the water heater normally this is on the wall next to or very close by your hot water tank.
A water pressure gauge sizing expansion tanks for water heaters can be a complex engineering challenge but residential expansion tank sizing has been simplified through the use of calculators.
When your water thermally expands a water heater expansion tank prevents unwanted increases in pressure.