Why Is My Water Heater Making A Hissing Noise?

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There is a water heater in virtually every Singaporean household to supply hot water. It is usually silent when in use, but sometimes it emits a hissing sound. This situation happens more often for older heaters.

Noise emission from any home appliances is typically indicative of a problem. Hence it is important for families to find out what is causing it. If the problem is severe, it may require professional water heater replacement services. Some of the possible reasons a water heater hisses are listed below:


High Water Temperature

If your water heater is hissing immediately after use, it could be your heater’s safety mechanism working. The 707 Compact Instant Water Heater, for example, has an in-built pressure release device that allows for the safe venting of excess pressure and hot water. However, this does not mean that you can ignore the hissing. It could be that the water level is set too high, or that the internal thermostat has failed. To properly identify and fix the issue, it is advisable to seek professional help.


Faulty Relief Valve


The temperature and pressure relief (TPR) valve that manages the safe venting of hot water and pressure may be faulty. This can cause the faulty valve to hiss, even when at normal pressure and temperature. Finding out the reasons why your water heater is corroding helps immensely in preventing the TPR valve from failing. If you spot a ring of rust around the valve, it is time to take corrective action and prepare for a water heater replacement.



When using a storage water heater for some time, the water level in the tank drops, prompting a fresh injection of cold water. This results in moisture condensing on the outside of the tank. The flash evaporation of the condensation that rolls down to the hot surface produces a hissing sound.


Water Heater Leaking


If your water heater is constantly hissing, it could be a sign of a faulty water heater. A small leak may have sprung on your water heater. There are many reasons behind a leaking water heater. Following the tips to identify water heater leaks and fix it is a great way to prevent your water heater from hissing. If you are having trouble fixing it on your own, you can seek professional water heating leaking services.



Most families in Singapore do not have the expertise and tools to fix the hissing sound coming from their water heater. Replacing the TPR valve, fixing a leak, or identifying the root cause of the issue can be a complicated task. That is why you should check out the past works of Water Heater City Singapore and engage in their professional water heater services for a hassle-free experience.


Water Heater City Singapore offers complete water heater services for both storage and instant water heater tanks including water heater installation and replacement, and water heater leak. We can provide the supply and installation or replacement of Singapore’s most popular water heater brands like Ariston water heater, Rheem water heater, Joven water heater, 707 water heater, Rubine water heater, and Champs water heater. If required, we are also able to open a false ceiling, patch it back up and paint it to restore it to its original condition. We have over 10 years of experience for installation of water heaters and have done hundreds of water heater installation cases for landed, condo and HDB, including complete one-stop installation above false ceiling, plastering, and resealing false ceiling. We are a highly recommended Water Heater Services Company in Singapore, with many delighted customers and reviews over the years on Google and Facebook. WhatsApp us at +65 8241 0032 for transparent quotations and honest pricing for all your water heater needs. We also provide fast and efficient service to solve any of your water heater needs!