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When your water heater making noises, listen to it carefully as it is warning you about the underlying problems it is facing. Like in cases of every other home appliance, a knocking sound from the water heater is never a good sign.


Commonly, when a water heater is making the knocking sound, it is because of the mineral deposits at the bottom of the tank. These minerals can overheat your water heater and cause it to disintegrate slowly. This article aims to inform you about why your water heater is making noises and how you can fix it.


Why Is Your Water Heater Making Noise

As mentioned in the very beginning, in most cases of your water heater is making noises, it is because it is trying to warn you about the loose minerals or sediments that have been piling at the bottom of the water tank.


The water heater’s elements for heating are located at the bottom of the tank; that is where the sediment deposits and blends with water.  The knocking noise is usually a result of the water underneath the sediments heating up and trying to escape the sediment level. This problem may lead to the water heater overheating and causing it to slowly worsen to leak or to burst.

The solution to this problem is simply draining and flushing the water. You can get a professional to do it or find out the proper way of doing it yourself from this article and just take action into your own hand.


How To Fix Your Water Heater From Making Knocking Noises

The step-by-step process to drain and flush your water heater tank so that it stops making knocking or popping noises is elaborated below.


Step 1: Turning Off The Water Heater

The first and the foremost step of draining our water heater tank is to turn off the power supply entirely. This is vital because if you let the electric features function with no water left in the tank, it can hamper the water heater features and cause bigger problems.

If you have a gas water heater, turning the gas valve button to pilot should suffice. If you have an electric water heater, you will have to turn off the water heater from the circuit breaker.


Step 2: Turning Off The Cold Water Supply

In the next step, you will have to shut off the cold water supply to the water tank. This will prevent more water from coming to the tank and help the process of flushing the water tank properly. To stop the cold water supply, you will have to find the cold water shut-off valve. In most cases, it is located at the top of the water heater. All you need to do is shift the valve into the off-side.


Step 3: Turning On At Least One Hot Water Tap Around The Home

In this step, you release pressure on the water supply lines by turning off the hot water taps in the kitchen, bathrooms, and anywhere else in the household except one while you flush the water heater. If not, this will form a vacuum in the pipes while draining the tank and interfere with the flushing process.  So it is necessary to ensure turning on at least tap before starting.


You must let the water heater cool down for about half an hour before the next step.


Step 4: Attaching a garden hose to the drainage tap

Once all the precautionary steps are taken, you will have to connect a garden hose to the water tank. Usually, there is a valve for you to connect the hose at the bottom of the water tank.


Preferably, the hose should have its end outside or into a large container. In case that is not manageable, you may need to arrange another way for the water to out o your house to avoid flooding the basement.


Step 5: Turning on the Hose

After you connect the hose to the tank, it is the most important step of the process. This is the step where you will turn on the hose and drain the tank. In the beginning, the water may come out discolored as the sediments are coming out with it.


Step 6: Flushing the Water Heater

This is the step that will help you get rid of the knocking noise in your water heater. To flush your water heater, you will have to turn on the cold water tap going in the water heater. Let it flow for about 15 minutes. You can also keep it on until the water coming out of the hose is colorless and free of sediment particles. Once you completely flush the tank, turn off the cold water tap.


Step 7: Restoring the Water Heater

Once you have successfully flushed the water heater tank, you can conclude the process by restoring the water heater to its functioning state.

You might want to wait for half an hour before you turn on the hot water tap again. Once you wait for an appropriate amount of time, check if the water heater is working normally or not. If it takes a while, DO NOT PANIC.


Usually, water heaters take around sixty to ninety minutes to fully recover. In case it does not function properly, there may be a bigger underlying problem that requires the expert’s attention.



Water heaters making noises may be a common thing, but it is not a trivial thing. You need to react to the noise and take proper actions before it goes out of hand and causes a lot more damage. The knocking noises are an indication of sediments piling up in the water tank. If this is not taken care of immediately, it can lead to the water heater overheating and leaking or bursting in the far future.


Hopefully, this article has informed you of what you need to know about water heater making noise and prepared you to deal with situations like this in the future.

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