water heater banging noise

Is your hot water heater making a banging noise? We’ve had customers ask us about hissing water heaters and whistling water heaters in the past, and now it’s time for us to check another one off our list. Why is your hot water heater is making banging noises, and what can you do about it?

Possible Causes of a Banging Water Heater

  1. Sediment build up – the more and more you use your water heater, the more sediment will build up at the bottom of the tank. This is just natural and unavoidable. The banging or popping noise you hear could be the result of air bubbles escaping from beneath the sediment and rising up to the top of the tank.
  2. Too much pressure – if the insides of your water heater are under high pressure, you might also experience loud banging noises. This is especially true if you do not have an expansion tank installed. As pressure rises within the hot water heater, it eventually reaches a breaking point, and then the pressure is released with a loud bang. This can either be a normal sound – or a very dangerous one. Do not ignore it.
  3. Issue with the internal baffle – depending on your water heater manufacturer, your banging issue could be directly related to the placement of the baffle inside the unit. A baffle that is out of place can lead to loud banging noises within the unit, as well as a host of other issues.

What to Do When Your Hot Water Heater Makes Banging Noises

OK, so maybe you’ve figured out why your water heater is making banging noises – but now what? How do you stop it, and make sure it is done correctly and safely?

The short answer is, call a plumber. We know it’s not the answer you’re looking for, but trying to DIY your own water heater repair can be dangerous, complicated, and potentially void your warranty. Water damage caused by an unlicensed repair may also not be covered by your homeowner’s insurance, exposing you to astronomical repair costs.

The good news is, if you need help with water heater repairs in Tracy, Manteca, or Mountain House, we’re just around the corner.

But what if you’re in another area, and you can’t find a good plumber? If you absolutely need to do a DIY repair, here’s where to start:

  • Flush the tank – if it really is an issue of sediment build up, it means it is time to flush your tank. You can do this yourself or have a professional handle it for you. This should be done on a yearly basis.
  • Check the expansion tank – if you do have an expansion tank and are still hearing hot water heater bangs, have the expansion check thoroughly inspected for any malfunctions.
  • Install a water hammer arrestor – a water hammer arrestor is a relatively simple fix that is an alternative to installing an expansion tank. This is a useful solution for homeowners who do not have an expansion tank installed, but don’t want to spend the money on installation.
  • Rotate the baffle – as mentioned above, a misplaced baffle could be the cause of the banging hot water heater. Recently, we were able to remove the blower assembly for one of our customers and rotate the baffle 180 degrees. This stopped the banging noise and improved the functionality of the water heater.

Share Your Helpful Tips

Even though our team at Simpson Plumbing has more than a decade of experience repairing and replacing both residential water heaters and commercial water heaters, we’re still surprised by some of the stories we hear about banging hot water heaters.

Do you have first-hand experience dealing with a banging hot water heater? We want to hear about it. Share your tips and experiences in the comments below.