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Common Water Heater Noises and What They Mean

water heater noises
Fix January 22, 2020
Arthur Brodskiy
Arthur Brodskiy


Your water heater is one of the most critical components of your plumbing system, and one of the most expensive to replace. It goes without saying that any sort of strange noise coming from your water heater should be cause for concern. It’s actually normal for you water heater to make some noise, but different noises can mean different things. 


Popping, rumbling and sizzling noises indicate some of the more serious water heater problems, while tapping, screeching and humming sounds could involve easy fixes and cause little concern. In this article, we’ll go over each noise, starting with the most severe. 


Popping or Rumbling Noise


The popping, rumbling, or gurgling noises associated with water heaters are a symptom of one of the most common water heater issues. Not only is it common, but it can also be tied to a number of other noises you might be hearing coming from your basement, garage or crawlspace. For these reasons, we’re going to pay special attention to these noises and refer back to this section throughout the article. 


What Causes It?


You probably know that your tap water contains some trace amounts of minerals. Two of those minerals — calcium and magnesium — have a knack for taking up permanent residence in water heater tanks. That’s because when the water in the tank is heated to temperatures high enough, the minerals start to settle on the bottom of the tank. 


Once the water in the tank starts to cool down, some of the water gets trapped under the layer of sediment. When the water heater turns on again, the water under the sediment gets hotter and hotter until it pops out from under the mineral buildup. This can happen in either gas burner or electric water heaters. Electric water heaters have a heating element inside the tank that can also experience the same mineral buildup that occurs at the bottom of the tank. 


Why You Should Be Concerned


Sediment buildup can do permanent damage to your water heater if it isn’t dealt with. As time goes by and your water tank collects more and more sediment, your tank becomes worse at it’s main job — holding water. This can cause water to boil over in the tank. Sediment can also wear out the anode rods in your water tank and corrode the tank walls, leading to cracks and leaks.  


The Solution


The solution to the sediment problem is to force the sediment out of the water tank. You do that by flushing the tank. Ideally, you should be flushing your water heater tank once every year to keep it healthy and make sure it lasts you many years. 


How to flush your water heater tank:


  1. Turn off your water heater’s gas or electricity.
  2. Turn off or close the water heater’s cold water supply valve.
  3. Switch the thermostat on the tank to “off” or “pilot.”
  4. Open the hot water faucet on any sink or tub in the house.
  5. Attach a garden hose to the drainage spigot on the water tank.
  6. Open the spigot and drain the water into a bucket.
  7. When the water starts to run clear, open up the water heater’s cold water valve.
  8. Continue draining the water until it runs clear again.
  9. Close the drainage spigot and disconnect the garden hose.
  10. Turn on the thermostat and gas or electricity.


In addition to flushing the tank, if you have an electric water heater you may also have sediment and scale buildup on the heating element inside the tank. Flushing the tank won’t be able to solve this problem. Instead, you should look into replacing your electric heating elements. 


Sizzling Noise


While not as loud or irritating as the rumbling noise caused by sediment, any type of hissing or sizzling noise coming from your water heater will likely cause you concern.


What Causes It?


One of the possible causes of sizzling is simple condensation. Pretty much all water heaters collect some amount of condensation on the outside of the tank. When that water comes into contact with the burner unit, it can cause a sizzling sound. But condensation isn’t the only possible source of water. If your water tank has a leak in it, that leaking water can also hit the burner unit. 


Why You Should Be Concerned


If the sizzling is indeed the symptom of a leak, you could face some serious damage if you don’t act fast. Water leaking from your water heater can cause structural damage to the basement or garage floor where it’s located. Small cracks in the water tank can create weak points that can lead to a rupture of the tank, causing a flood that can cost thousands of dollars to repair.  


The Solution 


A leaky water heater can be a serious repair job depending on the location of the leak. However, just because you have a leak doesn’t mean your water tank is going to explode. If the leak is coming from the attachment at one of the inlet lines, you might just need to tighten or replace the attachment. If the leak is due to a crack on the water tank, you might need to get a brand-new tank.  


Screeching Noise


A screeching noise coming from your water heater is most likely being caused by a partially closed valve. The partial obstruction means the water has to pass through a smaller opening, leading to a spike in pressure and a high-pitched, screeching noise. Simpy opening up the valves on the inlet hoses all the way could solve this issue immediately. 


Ticking Noise


Ticking sounds are actually pretty normal for water heaters. If you have a check valve on top of the water heater, the sound could be coming from there. The ticking is the sound of the check valve doing its job and preventing water from flowing in the wrong direction. 


It’s also possible that the ticking noise is coming from pressure fluctuations and the expanding or contracting of copper pipes. If your home has copper piping, you could try turning the thermostat on your water heater down by 5 or 10 degrees and see if you notice any difference.


Humming Noise


Humming noises are common in electric water heaters. Electric heaters have a heating element that sits vertically inside the tank. The element can become loose over time, allowing water to flow between it and the tank wall, which causes the humming noise. The solution? Tighten the heating element. 




There are many noises that could be coming from your water heater, and some are more serious than others. Popping or rumbling sounds hint at sediment buildup that should be addressed. Sizzling sounds could be coming from condensation or something more substantial, like a leak. Screeching, ticking and humming sounds might need nothing more than a simple adjustment to correct.

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