Thermal Expansion Valve Hot Water Heater

Both products absorb the excess pressure in the plumbing system created by thermal expansion.

Thermal expansion valve hot water heater.

Nor does the standard temperature and pressure relief valve adequately correct the water heater thermal expansion problem. Thermal expansion tanks are used to prevent plumbing system and or water heater damage and unnecessary relief valve discharge caused by excessive pressure from thermal expansion prevent dangerous pressure build up protect household appliances and fixtures external baked epoxy polyester coating provides a durable appliance finish. A dripping temperature and pressure relief t p valve on the water heater is an indicator of a potential thermal expansion problem. When water is heated it expands this is called thermal expansion.

When 40 or more gallons of superheated water is suddenly brought to atmospheric pressure and instantaneously vaporizes the massive expansion can launch your water heater through your house. This is the valve with the small handle or lever that automatically opens when either the temperature or pressure inside the heater tank exceed a set limit usually 150psi 210 f. A temperature and pressure t p relief valve is not considered a thermal expansion device. 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.

The only truly effective solution is to install a water expansion tank that provides the extra space for water expanded through heating. This blockage can render the t p valve useless and potentially lead to hot water heater explosions. This is because when water is heated its density decreases and its volume expands see below. As plumbers know the expansion tank equalizes pressure throughout the plumbing system by providing a space for hot water to flow into.

The tprvs themselves are not usually a problem on water heater installations as they come installed in the water heater. For example water heated from 90 f to a thermostat setting of 140 f in a 40 gallon hot water heater will expand by almost one half gallon.