Water Heater Making Noise When Water is Off

Isn’t weird that your water heater makes noice when water is off?

These noises can range from popping and crackling sounds to humming or even water running-like noises. While some of these sounds may be harmless, others could indicate underlying issues in the water heater system that need attention.

By understanding the root causes of these noises, you can take appropriate measures to fix them, ensuring the safe and efficient operation of water heater.

In some cases, the solution may be as simple as regular maintenance like flushing and cleaning sediment buildup, whereas other situations may require the assistance of a professional plumber who may change some parts inside your water heater.

It is crucial not to ignore these noises, as failing to address them can lead to more extensive and costly damage over time.

Water Heater Making Noise When Water is Off


Some of the reasons why water heater makes noice when water if off include faulty relief valve, different behaviour of pipes, sediment or just loose components inside the heater.

  1. Temperature

One possible cause could be a creaking noise in the plumbing system as the pipes expand and contract due to temperature changes.

  1. Faulty Relief Valve

Another possible issue is related to a faulty relief valve. A damaged relief valve sometimes generates noise even when the water is off. This valve is responsible for releasing pressure and prevents the tank from exploding if the internal temperature of the water heater becomes too high.

Related: Can Water Heater Explode

  1. Sediment 

Sediment buildup in the tank can also contribute to noise in a water heater. Hard water isn’t a good option for your water heater. Over time, minerals like calcium and magnesium collect in the water deposit at the bottom of the tank. You may hear some rumbling or boiling sound, while heat is trying to go up and blow these sediments. 

Of course, that water is not so hot that it could actually boil, but anyway, water will move and expand due to higher temperature while producing weird noices.

  1. Loose components

In some cases, the noise could be the result of loose components within the water heater. As these components vibrate, they can create humming sounds that homeowners hear even when the water is off. It is essential to have regular maintenance and inspections to ensure that all parts are properly tightened and functioning correctly.

Related: Are Water Heater Elements Universal

If you are unsure about the cause of the noise, it is best to consult a professional to determine the appropriate course of action. A skilled plumber can further diagnose the issue and recommend any necessary repairs or maintenance tasks. With proper care and attention, your water heater should operate quietly and efficiently, providing hot water for your home without any unnecessary noises.

Solutions to Common Noise Problems


If you are experiencing noises when your water heater is off, there are a few potential solutions you can try:

  1. Sediment Buildup: Over time, sediment can accumulate in the bottom of the water heater tank, causing popping or rumbling noises when the heater is off. Flushing the tank to remove the sediment may help alleviate this issue. It’s well known that most of the households get hard water.
  2. Thermal Expansion: When the water heater is off, changes in temperature can cause the pipes to expand and contract, leading to knocking or banging noises. Installing a thermal expansion tank can help absorb these fluctuations and reduce the noise.
  3. Loose Pipes: Loose or improperly secured pipes can rattle and create noise when the water heater is not in use. Inspect the pipes and ensure they are securely fastened to eliminate any unnecessary movement.
  4. Water Pressure: High water pressure can lead to banging or hammering sounds in the pipes, even when the water heater is off. Installing a pressure-reducing valve can help regulate the water pressure and minimize the noise.

Related: House Pressure At 100 PSI

Prevention Measures for Future Noise

Regular maintenance and a few simple prevention measures can greatly reduce the chances of your water heater making noise when water is off. By following these steps, you can ensure that your water heater operates as quietly as possible.

Assess the expansion tank: This component plays a crucial role in regulating pressure and preventing noise. Make sure it’s correctly installed, and schedule annual inspections with a professional to ensure everything is working properly.

Regular flushing: Sediment buildup in the tank can create strange noises. Flushing or descaling should be done on tankless water heaters too.

Insulate pipes: Insulating your water pipes can help reduce the chances of knocking or vibrating noises. This method not only makes your system more efficient but also provides additional soundproofing. Usually plumbers suggest outdoor pipe isolation, but you can always use this type of isolation for your pipes in basement.

Install a water hammer arrestor: These devices prevent water hammer, a common cause of banging noises in the plumbing system. By installing a water hammer arrestor, you can effectively mitigate these noises.

Adjust the temperature: A water heater set to a high temperature might produce more noise, especially when heating water. Consider adjusting the temperature to a more moderate setting to lessen the likelihood of noise issues. Usually, the recommended temperature for a water heater is typically around 120 degrees Fahrenheit (49 degrees Celsius).

Incorporate these prevention measures and maintain your water heater routinely to ensure its smooth and quiet operation. By taking these steps, you can effectively minimize noise issues and extend the life of your water heater.

When to Contact a Professional

There are several instances where contacting a professional is the best course of action to address a noisy water heater. Some typical scenarios include:

  1. Persisting loud noises: If the banging or thudding noises continue even after adjusting the pressure-reducing valve, it may indicate a serious issue with the pipes or water tank. A technician can inspect and detect the cause of the problem.
  2. Whistling sounds: If your water heater emits a whistling noise, it can be quite concerning. The cause could be a faulty pressure-relief valve or a leaking water tank. A professional plumber can determine the exact reason and suggest the appropriate fix.
  3. Hissing or sizzling sounds: These noises might signify leakage or condensation on the burner. A professional will identify the source of the leak and repair it promptly to prevent further damage to the water heater.
  4. Inconsistent noises: If your water heater produces inconsistent noises, it can be challenging to diagnose the issue independently. Experts can find the root cause efficiently and provide the appropriate solution.

Bottom Line

We went through some of the most common reasons why water heater making noise when water is off. When dealing with any appliance that uses electricity, natural gas, or propane, remember that safety should always come first.

One should not attempt DIY repairs if they are not familiar with the equipment, its components, or potential dangers. Always contact a professional to ensure the safety and integrity of your water heater and avoid potential risks.

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