When homeowners complain of hearing a loud noise from their water heater, it’s typically one of two noises:

  • A popping/rumbling noise
  • A sizzling noise

Both of these noises are usually caused by one culprit: sediment buildup. However, there are other issues that can cause these noises.

In this blog, we’ll walk you through each of these noises and the issues which cause them. We’ll also give you some handy solutions which may resolve them.

If you prefer to have a professional plumber diagnose and repair your water heater, feel free to reach out to us or learn more about the water heater repair services we offer.

Noise #1: Popping/rumbling

As we mentioned above, a popping or rumbling noise from your water heater indicates mineral buildup at the bottom of your tank.

Over time, minerals in your home’s water create a layer of sediment at the bottom of your water heater. This layer of sediment traps water underneath it. That water can become superheated, and once it reaches a boiling point, can push air bubbles through the sediment build-up. This creates the loud popping or rumbling noise you’re hearing.

So, what causes sediment buildup?

Sediment buildup is a natural occurrence. The cause is from minerals that enter the water heater and settle at the bottom of your tank. The “harder” your water is, the faster sediment buildup occurs.

To prevent sediment buildup in the future, it’s important to have your water heater professionally flushed every year. You can also install a whole-home water softener, which can reduce the amount of minerals in your water, and therefore the speed at which those minerals build up in your tank.

If you allow sediment to remain in your water heater, it will not only continue making a popping noise but can increase your energy bills and eventually cause damage to certain parts of your tank water heater.

What to do: Reach out to a professional plumber for help. They will likely recommend that you flush your water heater to ensure that the sediment is removed from the bottom of your tank.

Noise #2: Sizzling

There are a few different reasons why your water heater could be making a sizzling noise, including:

Sediment buildup

As we mentioned above, minerals can create a sediment layer at the bottom of your water heater.

The water trapped below this layer of minerals becomes extremely hot. When that hot water pushes through the sediment layer, it hits cooler water and the contact makes a sizzling noise.

As we mentioned above, if you think sediment buildup is your issue, you’ll want to call a plumber to flush out your water heater and remove any sediment from your tank.

A leak in the tank

If you hear a very quiet sizzling noise when you’re in the same room as your water heater, the culprit might be a small leak in your tank.

Because the water inside of your water heater is so hot, if there’s a leak, it can make a sizzling noise when it hits your cold floor.

If you think you might have a leak, take a look at your water heater. If you notice any moisture on or underneath the tank, you probably have a small leak and need to call a professional plumber to fix it.


If you have a gas water heater, the sizzling noise you’re hearing could just be condensation dripping onto the gas burner.

Unlike an electric water heater, which has a heating element inside the tank, a gas tank water heater has a burner that sits directly beneath the tank of water. When condensation forms on the bottom of the tank and drips onto the gas burner, a sizzling noise occurs.

Condensation forming is normal, so if you hear a soft sizzling every once in a while, there’s no reason to be concerned. However, if you’re hearing sizzling more often than normal or it’s very loud, you’ll want to reach out to a plumber to double check that your water heater is working correctly.

Need a professional plumber to quiet your water heater? Contact Roy’s

If you think you have one of the issues listed above, you’ll need to enlist the help of a pro. At Roy’s, all of our local plumbers in Buffalo are highly trained, and will accurately diagnose your water heater as well as provide recommendations on the best solution going forward.

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