Loud Sounds from Heater?

Ever experienced loud sounds coming from your water heater?

Check out the sample sound clips below:

Recording of intermittent beeping

Recording of continuous whistling

The sounds may be described as a continuous whistling noise or high pitched beep. It is intermittent and may be heard even when the heater is not switched on. The sound is produced by the relief valve, a safety valve fit on every storage heater.

What is a relief valve?

The purpose of a relief valve is to release water from the tank to avoid pressure build up, thus protecting the tank from rupturing.

Pressure is released through clean water droplets which flow out of the valve. It is important that the valve is not blocked so at times, a tube is connected to a drainage point for the water to flow freely.

A relief valve up close. Relief valves are installed at the inlet of the heater

What causes this sound?

There are two reasons why the relief valve is producing a sound.

Situation 1: The relief valve is faulty
The relief valve is not working properly and can no longer withstand the water pressure coming from the heater. It may even be reliving a large amount of water, like a small tap.

Solution: If the valve is faulty, it is a simple fix. Simply replace the valve.

Situation 2. The incoming water pressure is too high
Relief valves handle pressure from both the water heater tank and the water pipes. Water pressure in most homes in Singapore are around 2.0 to 2.5 bars.  In the rare event that incoming water pressure exceeds 3 bars, the relief valve is likely to produce a sound.

This guy’s water pressure is way off the charts

Solution: Reduce the water pressure

Call the town council or building management to adjust your incoming water pressure. Pressure that is too high will damage your other water-related appliances in the long run.

If this does not work, reduce the water pressure to the heater by fixing a pressure reducing valve just before the inlet of the heater. This can be done by an external plumber and costs including installation are estimated at $150.

Pressure relief valves are easily available and may be installed by any plumber

In conclusion..

If you hear sounds from your heater…

Contact your warranty provider or a professional for advice. As with all devices, there is always a possibility that the valve may fail. Address the issue as soon as you can before the heater becomes a safety hazard!



Amanda is an education specialist at AOS Bath. She enjoys building a trusted network by sharing knowledge. Making difficult concepts simple and engaging is rewarding, on both ends.