Water heater pressure relief valves are important safety features designed to relieve pressure from a water cylinder in case the hot water cylinder thermostat malfunctions. As water gently heats up it expands, if the thermostat malfunctions and continuously heats the water without pausing the tank would eventually burst. The pressure valve releases this pressure before this can happen.

A build-up of mineral salt, rust, and corrosion can cause a pressure valve to size and fail. Regular testing and replacing the valve when defective are the best ways to avoid a disaster.

We recommend testing the hot water cylinder each year but some manufacturers recommend 6 monthly.

How to test your hot water cylinder pressure valve

Gently pull the lever on top of the valve upwards and check that hot water is expelled through the overflow tube. This hot water simply drains onto the ground.  If no water flows through the pipe or you get just a trickle, replace the valve. If you don’t regularly test the pressure valve you will need to replace it more frequently. This test will actually make your water heater function better and it’ll be safer.

When to replace a pressure valve

If you notice it dripping before you conduct the test, or if nothing comes out of your valve when you pull the test lever, or you can’t reset the lever to stop the valve from dripping, you should replace it.

If you think your hot water cylinder pressure valve needs looking at call us on 1300 35 35 37 or to book online click here