Electric Hot Water Heater Expansion Tank

The tank has two sections that are separated by a rubber valve.

Electric hot water heater expansion tank.

When water is heated or a hot water faucet is turned off abruptly pressure builds from expanding water molecules. 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. When an expansion tank is installed the extra water volume automatically rushes into the tank. When your water thermally expands a water heater expansion tank prevents unwanted increases in pressure.

This ultimately protects it from damage. 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. Since water expands when it is heated due to thermal expansion the water heater creates extra water volume every time it heats water.

What size expansion tank do i need. The hot water expansion tank is a two gallon tank that hangs off of your hot water system or your boiler. You install the expansion tank down the line from the inlet valve that sends hot water into your home. It is used to absorb excess water pressure.

Water expands by roughly 2 as it heats up from 50 f to 120 f. As water heats inside the water heater and exceeds the capacity of the tank the overflow rushes into the expansion tank. The expansion tank serves as a backup system to prevent overworking your plumbing. 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.