The Ultimate Guide to Water Heater Popping, Banging, and Strange Noises

Last Updated On June 21, 2024

Updated on April 25, 2022



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water heater popping, banging, and strange noises

Do you hear water heater popping noises every time you turn on your hot water tap in your tank-type water heater? If so, you need to diagnose why your hot water heater is making strange noises and take action before it causes damage to your water heater. 

In this PlumbingNav guide, you will learn: 

  • Why Is My Hot Water Heater Making Popping Noises?
  • What Causes Hot Water Heater Banging Noises?
  • How to Diagnose a Popping Water Heater
  • How to Stop the Water Heater Popping Sound

What's In This Guide?

      Why Is My Hot Water Heater Making Popping Noises?

      Water heater popping noises, sometimes described as banging noises or a knocking sound, develop due to sediment buildup at the bottom of the tank. Since this tends to be the cause, this problem occurs in tank-style water heaters instead of tankless water heaters.  

       In addition to the popping noises, here are additional signs of sediment buildup in your water heater:

      • Higher utility bills
      • Inconsistent water temperatures
      • Reduced amount of hot water

      We will cover the reasons your water heater may get sediment buildup so you can take the proper steps to prevent it from happening in the first place.

      Hard Water 

      Sediment buildup consists of the minerals in your home’s water. Hard water refers to water with high amounts of calcium and magnesium in it, measured in milligrams per liter of calcium carbonate levels. Refer to the following water hardness classifications:

      • Soft: 0 – 60 mg/L
      • Moderately hard: 61 – 120 mg/L
      • Hard: 121 – 180 mg/L
      • Very hard: 181 mg/L

      Hard water creates mineral deposits when heated, and these deposits become the sediment buildup in your water heater. 

      High Water Pressure 

      Water with high-pressure levels of more than 50 psi can lead to mineral deposits in your water heater more quickly. You may also notice high water pressure damaging the pipes in your home and leading to unnecessary water waste. 

      Not Performing Regular Maintenance 

      Your tank-style water heater requires regular maintenance. As part of this maintenance, you need to flush the water heater and replace the anode rod. Both of these actions clean out sediment in the tank. 

      Flush the water heater once a year, and change the anode rod every 3 – 5 years. 

      How To Diagnose A Popping Water Heater

      To resolve the popping water heater problem properly and prevent it in the future, you should learn the cause. Diagnose the cause of the problem by examining these items on your water heater. 

      Check Water Pressure Levels

      You can check the water pressure level by connecting a pressure gauge to one of the faucets in your home. To prevent sediment buildup, you want water pressure levels to fall below 50 psi. 

      Examine Water Hardness

      You can research water hardness in your area and send your water to a water testing facility to get exact hardness levels. However, you can also keep an eye open for the following signs of hard water:

      • Stiff laundry / need for fabric softener
      • Soap scum on fixtures and dishes
      • Buildup in sinks and tubs
      • Film on hands after washing them
      did you know what are water heater popping noises

      Steps For How To Stop The Water Heater Popping Sound

      When you notice a problem during your diagnosis, you need to take action to stop the water heater popping sound once and for all. A popping sound from sediment in your water heater signifies upcoming water heater troubles much more problematic than the noise. 

      Some problems caused by sediment buildup in your water heater include:

      • Tank damage
      • Heating element failure
      • Lower water quality
      • Clogged drains
      • Potential explosion

      When you flush the tank, you will get rid of a majority of the sediment buildup. Follow these steps on how to flush your water heater tank yourself:

      How To Flush Water Heater Tank

      1. Turn off power

      Turn off the power to your water heater, whether you have a gas or electric water heater. Water and electricity don’t mix. You also don’t want the water to damage the components of your water heater in any way. 

      1. Attach a hose to drain valve

      You will attach a hose to the drain valve, usually at the bottom of your water heater. You will then place the end of the hose in a safe place outdoors or near a drain. 

      1. Turn on hot water faucet

      You need to turn on a hot water faucet in your home to allow airflow into the hot water, preventing air blockage. 

      1. Open drain valve

      Now, you can slowly open the drain valve, which will release the water from the water heater tank. 

      1. Close cold water supply valve

      Close the cold water supply valve, usually on the top of the water heater, to prevent new water from entering the water heater tank. 

      1. Flush until no more sediment in the water

      Allow the tank to completely drain. Keep an eye on how much sediment you see in the water. If you notice sediment in the water at the end, you should fill up the tank and flush it again until you don’t see any sediment in the water anymore. 

      1. Close drain valve

      Now, you can close the drain valve and remove the hose. If you forget this step, you will continue to drain the tank, and it will never fill up. 

      1. Vinegar Soak (Optional)

      Some people choose to pour a gallon of cider vinegar in the tank for its ability to break up sediment. Ensure you close the drain valve and let the vinegar sit for six hours before flushing the vinegar out thoroughly. 

      1. Refill water tank

      Turn on the cold water supply again to refill the water heater tank. You will know that the tank is full again when you notice water flowing from your open hot water faucet at full pressure. Keep in mind there may still be air in the lines, but this will pass.

      1. Restore power

      Restore power to the water heater to heat the new water in the tank. You will need to wait a couple of hours before you will have hot water again. The amount of time it takes will depend on the size of the tank and your water heater’s first-hour rating.

      Prevent Sediment Buildup In Your Water Heater

      Now that you removed the sediment, you need to take steps to stop the problem from happening in the future. Try these tips to prevent sediment buildup in your water heater tank. 

      Buy Water Softener 

      If you determined that your water’s hardness contributed to the sediment buildup in your water heater, you could benefit from purchasing a water softener. 

      You will place your new water softener near the water source to your home, and the water softener will remove the calcium and magnesium in your water. Plastic resin attracts the minerals in the water and replaces those minerals with sodium ions that won’t damage the appliances in your home. 

      Lower Water Pressure Levels

      To lower the water pressure in your home, you need to find the water pressure regulator near the main water supply line to your home. You will use a screwdriver to loosen the nut by turning it left.

      Quick Read FAQs About Water Heater Popping Noises

      Want fast answers to your questions? Read these frequently asked questions to quickly find the answers you need.

      How do I stop my water heater from popping?

      To stop your water heater from popping, you should flush the water heater tank since sediment buildup is the cause of these strange noises.

      Is it normal for a water heater to make popping noises?

      More homeowners complain of popping noises from their water heater than any other sound. While not a good sign, you can resolve the problem relatively easily. 

      Is a popping water heater dangerous?

      A popping water heater does not necessarily indicate a dangerous situation. However, excessive sediment buildup can lead to scalding temperature and pressure valve malfunction. This then can lead to an explosion in the most dangerous situations, but it is rare and avoidable.

      Why is my heater making popping sounds?

      Sediment buildup creates popping sounds more than any other reason. If you hear popping, banging, or other strange noises from your water heater, that’s probably why.

      Do you also hear other noises from your plumbing pipes? See this related post where we discuss each one, and how to troubleshoot them.

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      About Plumbing Navigator

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      We write about “all things plumbing,” helping you navigate common questions, repairs, and the best plumbing products on the market.

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