Why an Electric Water Heater Keeps Making Hissing Noise

electric water heater noise
As an Amazon Associate, we earn from qualifying purchases at no extra cost to you.

A water heater is a device in a home that brings comfort in the house since it mainly helps in heating water at any time of the day, and it is fast. However, sometimes the water heater at home fails to work correctly as per their specifications due to some complications.

In some cases, you can notice that the hot water is making some hissing noise in the process. The hissing noise shows that the heater has some problems with it since it is not customary in water heaters. So this kind of noise needs fixing to reduce the noise since the noise brings destruction to the house.

Therefore, the water heater user must note the causes of the noises to replace or repair them when reducing the noise. In some cases, the heater can make the hissing noise normal if the heater is old enough for work.

However, the noise still needs reduction by fixing the possible areas of errors. Therefore, the user must keep checking the heater when using it and if it starts making noise, check the whole system of the possible errors to identify the causes of the noise.

The article below discusses the possible reasons for the electric hot water making noise when heating water. The reasons for the hissing noise in the electric water heater help you find a way to fix the parts making the noise or change the environment causing the noise.

Hissing noise in an electric heater can later cause more significant damages to a heater than it can fail to work. Therefore follow the guide carefully to help you fix the problem earlier for the safety of the electric heater.

Causes of hissing noise in an electric water heater

electric hot water heater hissing noise

1. Increase in temperatures in the tank

There is the production of a hissing sound when the water in the heater is too hot, as the valve releases some pressure that causes the valve to open to release the pressure that can cause an explosion of the tank. To fix the problem, you should lower the water heater temperatures. The low-temperature results in a low-pressure build-up in the tank.

The hissing noises will be produced when the water temperature is 140 degrees and above. When the temperatures are lowered to 120 degrees, the water heater will work comfortably without the hissing sounds since the pressure build-up is not high.

2. Closer condensation to the heater

When using the heater during the day, the tank refills, and users use all the water in the tank as it continues refilling. Therefore a large amount of cold water is required to fill the emptied tank. The addition of water to the tank after using the hot water causes condensation on the tank’s outer surface.

The hissing sound is produced as the moisture collides with the hot tank. An increase in condensation in the tank causes an increase in noises. Some situations increase the condensation rate and also the rate of hissing noises. Below are some of the reasons.

  • A small water heater. When the water heater is small for your household, for example, your family is too big, it means that a lot of water will be drawn from the tank, more condensation will occur, resulting in a more hissing noise.
  • The water heater tank is refilled with cold water. For instance, during the winter, the weather is too harsh, and therefore, the natural temperature of the water is too low. Consequently, it shows that the cold water used to refill the hot tank is extremely cold. As a result, the condensation in the will increase, thereby increasing the hissing noises.

3. A leaking tank

A leaking water heater tank

When the hissing of the water heater occurs almost the whole day, you may notice that the problem is no longer emptying the tank. However, there could be another more significant problem with the tank that needs to be fixed. Therefore, when the hissing continues, it is essential to take action as soon as possible. First, identify the problem by checking the water heating for hiss and leakages.

For the leakages, inspect the water escaping and look for any moisture escaping from the tank and gathering in the puddle in the bottom. If the tank is leaking, it is advisable to repair or replace it as soon as possible before the small leak gets worse or the tank bursts completely.

4. Availability of debris in the tank

Availability of debris in the tank

When there is a sentiment build-up in the bottom of your tank, there will be the production of hissing noises accompanied by other strange noises. This hissing problem occurs when the sediment builds up at the bottom of the tank.

The deposit comprises minerals available in the water that builds up and settle at the tank base. After a long time, the accumulation of the minerals becomes more, and the mineral layer thickens.

The thick mineral layer will cause the water bubbles to be trapped and turn to steam. That whole activity in the tank causes the hissing noises in the tank.

The problem of sentiment build-up is most common in places whereby the water is hard. Salty water contains many minerals, and therefore, they are likely to build up at the base of the tank.

In case you encounter this kind of problem, ensure that you consult a professional to identify whether the water should be replaced, or you can flash the build-up minerals.

Frequently asked questions:

  • How can one stop the hissing noise in an electric water heater?

Before trying to stop the hissing noise in an electric water heater, it is good to identify the possible reasons why the heater is making the noise. All this is because you can stop the heater from making noise by tampering with some parts that are good for working in the heater.

After finding the reasons, use the senses to guide what to correct to stop the noise. For example, if there are dirty sediments in the tank, try and clean the tank to prevent noise. Then, with the temperatures, try and reduce the temperatures to reduce the noise. Therefore, follow the causes to stop the hissing noise in the tank.


Hissing noise in an electric water heater is due to several reasons because of the regular use of the tank-like in the sediments, which is due to the water filling the tank, which can be dirty as the dirty particles accumulate causing the hissing noise.

The article above shows the possible reasons people can ignore but cause the noise in the electric water heater. The report gives a good directive that you can follow to identify the hissing sounds in your water heater.

However, if you do not know about the hissing noise in the electric water heater, it is essential to call a professional to help fix the problem. Failure to fix the noises at an early stage causes too much noise in the heater that can damage the whole system.

Lastly, average temperatures in the system must not be above 140 degrees Celsius as they cause excessive accumulation of high pressure in the tank that causes condensation and increases the hissing noise as the valve works hard to open when working. Moreover, the temperature must not be lower than 120 degrees since the temperature increases the rate of bacteria growth.

Leave a Comment