Why is my hot water heater making a popping sound?  Pippin Brothers, Lawton, OK
March 18, 2015

Symptom: Your water heater is making a popping, rumbling noise.

Problem: The water heater tank has sediment/scale build up (minerals from hard water).

Solution: The tank needs draining and flushing.

If you don’t the flush the tank, the water heater’s efficiency will drop and—in the long run—the tank can deteriorate and spring a leak (meaning you’ll need to replace the water heater).

In this article, we’ll talk about:

  • Why sediment causes the popping noise
  • How to flush the water heater tank of sediment
  • How to prevent sediment/scale buildup in the future

Why sediment causes the popping noise

Basically, the popping noise is water is boiling underneath the sediment.

You see, sediment drops to the bottom of the tank where the gas burner is (for gas water heaters) . That gas burner starts heating water trapped underneath the sediment, causing it to percolate like coffee and creating the noise as a result.

While the noise itself is harmless, too much sediment can:

  • Eventually cause a leak—Sediment slows heat transfer from the gas burner to the water. This can cause the water heater to overheat, damage the inner lining and weaken the steel tank, leading to a leak.
  • Damage the electric heating element—Do you have an electric water heater? If so, the sediment can cover the electric heating element, causing it to burn out.

OK, so you see the severity of this problem, right?

Here’s how you fix it.

How to flush and drain the water heater tank in 10 steps

Please follow these instruction carefully or you may damage the water heater.

If you don’t want to do this yourself, please contact a professional Lawton, OK area plumber for help.

1) Turn off the water heater.

  • Electric water heaters: turn off the water heater at the circuit breaker.
  • Gas water heaters: turn the gas switch to pilot.

2) Turn the cold water supply lever to a 90 degree angle. This will stop more water from entering the water heater.

3) Connect a garden hose to the drain valve

4) Place the other end of the hose in an area where you can drain hot water (like a basement drain or outside)

5) Open the pressure relief valve and open a hot water spigot in the house. This will allow the water to come out of the hose.

6) Open the drain valve. Dirty water should start coming out of the hose. (Careful! It will be hot.)

7) When the water has been drained, now it’s time for the “flushing” part. If you opened the pressure relief valve, close it before turning the cold water supply on. Turn the cold water supply lever on the “open” and “shut” positions a few times. This should help flush out any remaining sediment in the bottom of the tank.  You’ll know you’re done when you only see clear water.

8) Close the drain valve and disconnect the hose from the valve.

9) Turn the cold water supply lever back in line with the cold water inlet pipe. Wait 10 minutes for the water heater to fill back up. Turn on a hot water faucet to purge any air out of the tank. When you start getting clear water instead of a cloudy air-water mixture, turn the hot water tap off.

10) Turn the water heater back on to start heating the water.

How to prevent sediment/scale build up in the future

To prevent sediment build up, install a no-salt water conditioner at your home’s water main.

This type of conditioner treats the water in such a way that it leaves the minerals (which are good for your body) in the water while preventing them from causing scale buildup in the water heater and your pipes.

Learn more about no-salt water conditioners.

Need help with your water heater today and live in the Lawton, OK area?

Contact Pippin Brothers for a water heater drain and flush.

Pippin Brothers is the Lawton-area’s most trusted heating, air conditioning and plumbing company. We’ve been serving Oklahoma since 1978. Contact us for more information.