Thermal Expansion Valve Hot Water Heater

This blockage can render the t p valve useless and potentially lead to hot water heater explosions.

Thermal expansion valve hot water heater. This is because when water is allowed to continuously drip from the t p relief valve minerals from the water can build up on the valve eventually blocking it. A temperature and pressure t p relief valve is not considered a thermal expansion device. The only truly effective solution is to install a water expansion tank that provides the extra space for water expanded through heating. Nor does the standard temperature and pressure relief valve adequately correct the water heater thermal expansion problem.

The thermal expansion relief valve can replace a water heater expansion tank because it functions similarly. 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. The tprvs themselves are not usually a problem on water heater installations as they come installed in the water heater. When water is heated it expands this is called thermal expansion.

As plumbers know the expansion tank equalizes pressure throughout the plumbing system by providing a space for hot water to flow into. Both products absorb the excess pressure in the plumbing system created by thermal expansion. This is because when water is heated its density decreases and its volume expands see below. A thermal expansion control valve is essentially a pressure relief valve installed at a water heater to prevent forming excessive pressures in the closed loop of water supply piping and water pressure tank when water is heated at the water heater.

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.