Water Heater Making Noises? Learn Causes of Noises and What to Do from a Charlotte Plumbing Company

Is your water heater making noise? Wondering if you need to perform maintenance or if you can just ignore the sounds? Worried that it might explode or stop working?

Water heater noises are quite common, and they are usually indicative of a problem that you will want to address. The following is a list of commonly reported water heater noises, plus solutions for each noise. We hope this helps you determine what actions you need to take to keep your water heater running at maximum capacity.

Water Heater Noise Overview

Your Water Heater is Making Crackling, Popping or Rumbling Noises

Your water heater heats water in the tank. As the water heats, bits of sediment are boiled out of the water, and these bits of sediment collect on the element tubes of your water heater. Layers of sediment become caked inside your tank, trapping water underneath the layers of sediment. When the water heats up, it bubbles up through the sediment deposits, loosening some of the sediment and causing it to become chunky.

The popping or crackling sound you are hearing is hot water forcing its way through the layers of sediment. The rumbling sound comes from chunks of sediment swirling around inside the tank.

What does this mean?

If your water heater is making crackling, popping or rumbling noises, you've got a problem with built up sediment in the tank. If your water heater is under ten years old, you can get away with using a deliming mixture to clean the sediment out of the tank and then flush and drain your water heater. (Click here for step-by-step instructions on how to flush and drain your water heater.)

It is advisable to flush and drain your water heater once a year to prevent this problem. Too much sediment reduces the efficiency of your water heater and reduces longevity. A well-maintained tank water heater may perform well for 15 years, but an unmaintained water heater will usually conk out at about 10 years.

If you flush the tank and it still is making noises, check the thermostat. If your thermostat is set at 125 degrees or higher, the noises may be created by the expansion and contraction of the tank and/or pipes. Reduce your thermostat setting to 120 degrees or lower (which is also the advised setting to prevent scalding) and see if the noises stop.

If your water heater is over ten years old, you may cause problems within the tank if you try to delime and flush it at this point. It's probably best to start investigating what type of water heater you want next and to prepare to replace the water heater soon. (Click here for details about different types of water heaters and details about what size and type of water heater will best fit your budget and your household's needs.)

Your Water Heater is Making Humming Noises

If you are hearing a humming noise, it simply means that your water heater element is loose and the water flowing around the element are causing vibrations that sound like humming.

What does this mean?

This is not a big deal at all. If it bothers you, you can tighten the element or have a plumber out to tighten it.

Your Water Heater is Making a Knocking or Hammering Noise

In the business, we call this "water hammering." This is literally a knocking of the pipes against the wall. This can happen because the pipes are not securely fastened and they are hitting the studs or the interior of the wall (due to expansion and contraction of hot or cold water going through the pipes). It can be caused by abrupt turning on and off of water also, such as a toilet bowl or water pump that does not have a holding tank to distribute the flow of water more carefully.

What does this mean?

It's not an urgent problem, but it is possible that you might end up with some wall damage after time if not corrected. It is not affecting your water heater in any way, so don't worry about replacing or repairing your water heater - that's not the source of the noise or the cause of the knocking.

Install (or have a plumber out to install) a water hammer arrestor and the problem will disappear.

Your Water Heater is Making a Screeching, Singing or Screaming Sound

High-pitched sounds come from water that is being forced through an opening that is too small. The cause is usually a valve that is not open all the way; the valve may be at your water heater or it might be closer to a sink or shower or appliance. Listen to see where the noise is coming from to determine the location of the valve.

What does this mean?

Your water heater itself is probably fine. You might need a new valve at the water heater itself, and that is not something to try to change yourself since the steam that is released from a water heater valve can burn or injure you. If the location of the noise is closer to a faucet or appliance, you may be able to replace the valve yourself. Just make sure to turn off the water to that sink or appliance, wait for the water in the pipes to cool (if the faucet or appliance has recently been used for hot water), and then work on the valve when you are sure it is safe to be handled.

Your Water Heater is Making a Hissing Sound

Hissing sounds usually indicate a leak. Look for water or steam coming from the water heater or a pipe leading to it.

What does this mean?

A leak requires repair by a professional. If the water heater is old, it may require a replacement. Make sure you aren't incurring water damage somewhere, and then call a plumber to service your water heater.

Your Water Heater is Making a Tapping or Ticking Sound

A tapping or ticking sound usually come from heat traps or check valves that have been installed to encourage water to flow in the proper direction. The noise might also come from water heating and cooling in the pipes.

What does this mean?

If the ticking or tapping noise bothers you, you can replace the heat trap with a dielectric nipple. However, this does not guarantee the noises will stop. The tapping or ticking noise is not indicative of any real problem, so see if you can just ignore it. No need to fix something that isn't broken!

A Charlotte Plumbing Company with Experience

Have you determined that you want to have your water heater serviced or checked? E.R. Services has been providing water heater repairs and replacements in the 30-mile radius of Charlotte since 1997. Give us a call at 704-269-1066 or click here to use our online contact form. We are committed to customer service, and such, we devote time and energy into diagnosing your plumbing problem and providing the most cost-effective and reliable solutions available. We look forward to working with you!

Other noises got you worried? Sorry, can't help you with those!

Article Summary

Quick question & answer: Why is my water heater making sounds?

Your water heater could be making sounds for various reasons. If it is making crackling, popping, or rumbling sounds, there is built up sediment in the tank. If it is humming, there might be an element loose that needs tightening. If it is screeching, singing, or screaming, it might need a new valve. Hissing sounds are indicative of a leak.