Water Heater Thermal Expansion Tank Failure

A thermal expansion tank is a simple way to solve this problem on most smaller water heater systems.

Water heater thermal expansion tank failure. If you think your expansion tank may be full of water unscrew the plastic cover on the bottom of the tank that exposes the schrader valve then and briefly press in on the valve s pin like you would to let air out of a tire. When the heater goes through a heat cycle the excess volume of water pushes into the tank and compresses the air but keeps the water pressure the same. The way that it works is this. When water is heated or a hot water faucet is turned off abruptly pressure builds from expanding water molecules.

Moreover if an expansion tank is absent the first sign that something is wrong is leaking. In older hot water heating boiler expansion tanks that do not have an internal bladder to keep air and water separate over time air in the expansion tank may become absorbed into the heating water. The diaphragm has ruptured or otherwise failed so there s nothing to keep the water out. Excess water when water is heated its physical volume increases.

Most of the time your tank is half water and half air. However if you do have a thermal expansion tank and leakage persists it may mean that the leaking pipes are within a closed water system. The purpose of an expansion tank is to provide a. An expansion tank is used to prevent issues related to excess pressure from your home s hot water supply.

Air may also find its way via the heating water to other air bleeders or vents in the system. It has a diaphragm separating both. This process is called thermal expansion and it can cause strain on your plumbing system. Air is compressible but water is incompressible.

It s estimated for example that the cold water in a standard 50 gallon water heater expands to 52 gallons when heated to 120 degrees fahrenheit. The tank is full of air. Condensation problems sometimes there may be excess condensation on the outside of the water heater tank. If the extra volume has nowhere to go it pushes on the walls of your plumbing.

Too much water with excess heat and pressure in a pipe will cause leakage. Expansion tanks are installed down the line from the inlet valve that supplies the water heater in your home. The water heater expansion tank serves as an overflow receptacle by absorbing excess water volume that occurs when water is heated as well as absorbing fluctuations in the incoming water supply pressure. If your water heater holds 50 gallons of cold water it will expand to about 52 gallons when it is heated.

Since water expands when it is heated due to thermal expansion the water heater creates extra water volume every time it heats water. When pressure increases the diaphragm is pushed upward.