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Property Types & Construction

Pressure Relief Valve

Definition and meaning of Pressure Relief Valve in real estate.

A pressure relief valve is a mechanical safety device installed on water heaters and boiler systems to prevent them from exploding by releasing water if internal pressure or temperature exceeds safe limits.

In more detail

As water heats up, it expands, creating pressure inside the sealed tank of a water heater or boiler. If the thermostat fails and the water overheats, the pressure can rise to dangerous levels that risk structural failure of the tank. The pressure relief valve is designed to open automatically at a set threshold, venting hot water and steam safely through a discharge pipe.

Home inspections routinely check this valve to ensure it is functioning and properly piped to prevent water damage or injury. Homeowners should test this valve annually to make sure the spring-loaded mechanism is not stuck.

Key facts

CategoryProperty Types & Construction
Also known asTemperature and pressure relief valve, T&P valve
Watch out forLeaking, corrosion, or a missing discharge pipe
Required byLocal building codes and safety regulations
Example

During a routine home inspection, the inspector lifts the lever on the water heater's pressure relief valve to confirm that water flows freely and the valve closes securely.

Frequently asked questions

Why is my pressure relief valve leaking?

A leaking valve can be caused by excessive temperature or pressure in the tank, a buildup of mineral sediment, or a failing valve that needs replacement.

How often should a pressure relief valve be tested?

Homeowners should test the valve at least once a year by lifting the lever to ensure water drains and the valve resets without leaking.

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