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Why Is My Water Heater Making Noises?

a technician working on a water heater

Do you hear strange noises coming from your water heater? Whether it’s a rumbling sound, a hiss, popping or high-pitched whistling, these noises will have homeowners scratching their heads.

Each type of noise a water heater makes could indicate an underlying problem in your plumbing system. Once you identify the type of noise coming from your water heater, contact a professional plumber to make the necessary repairs.

Why Is My Water Heater Making Noises?

Water heaters often make strange noises when they have maintenance issues or need repair. There are several noises that a water heater could make, so it’s important for homeowners to understand them and what each noise means so that they can take the proper action.

Staying on top of water heater maintenance is the best way to ensure that your water heater has a long lifespan and your home doesn’t experience a lack of hot water. Keep reading to learn about each noise your water heater could make. Remember to contact a professional plumber to handle water heater repairs for you.

Rumbling or Booming Noises

Hearing a rumbling or booming noise coming from your water heater most likely means there is sediment buildup in the water tank. When debris and minerals settle at the bottom of a water tank, they create a sediment buildup that can cause the tank to overheat.

Sediment buildup can occur when a water heater tank hasn’t been flushed regularly. To avoid this problem, schedule regular water heater maintenance with your plumber. If you are currently hearing these rumbling or booming noises, ask your plumber, who knows how to flush a water heater, to solve the problem.

Crackling or Popping Noises

As a water heater’s temperature goes up and down, the tank expands and contracts. When you hear a crackling or popping noise coming from your water heater, it’s the sound of metal expanding quickly.

Most of the time, these noises do not point to a maintenance issue with your water heater, especially if you only hear them sporadically. However, if you hear a crackling or popping noise all the time, check your water heater for leaks. Next, contact your plumber to inspect the water heater to ensure there are no other underlying issues.

Hissing or Sizzling Noise

Water heater leaks can occur over the lifespan of your water heater. Thankfully, they are easy for a professional plumber to fix. One sign of a water heater leak is when you hear a hissing or sizzling noise from your water heater.

Water heater leaks can lead to major problems, such as corrosion. Thoroughly inspect your water heater and the heating elements, and contact a plumber right away if you notice a leak.

High-Pitched Whistling or Whining Noise

When your water heater’s pressure relief valve does not work properly, your water heater might make a high-pitched whistling or whining noise. The pressure relief valve is an extremely important part of the water heater system because it prevents explosions.

If the valve isn’t working properly, too much pressure can build up in the water heater and lead to serious issues. Contact a plumber immediately if you hear a high-pitched whistling or whining noise from your water heater so that they can repair or replace the pressure relief valve.

Knocking or Banging Noise

If you hear a knocking or banging noise coming from your water heater, it’s most likely due to water stopping or rapidly changing directions in your pipes. This occurrence is known as a “water hammer” because of the loud thud the water makes when it happens.

Water hammers are usually due to a faulty valve or poor water pressure regulation. A professional plumber can get to the bottom of the knocking or banging noises and, if needed, repair the water heater equipment to eliminate the sounds.

a bathroom in a home

What Homeowners Need To Know About Cleaning a Hot Water Heater

All hot water heaters should be cleaned and flushed at least once a year in order to prevent sediment buildup and get ahead of potential maintenance issues. Additionally, if your water supply has high mineral content, it should be flushed more often. Ask your plumber to advise you on how often your water heater should be flushed to keep it working optimally.

While water heater flushing should be left to the professionals, it’s valuable for homeowners to know how the process works. Here is a step-by-step guide on how plumbers do it:

  • First, they turn off the power supply to the water heater. Electric heaters need to be switched off at the circuit breakers. For gas heaters, they turn off the gas supply and extinguish the pilot light.
  • Next, a plumber will locate the drain valve, which is usually towards the bottom of the hot water heater. They open the valve carefully since the water could be hot. Then, they leave the valve open as sediment and debris flow out until the water run clear.
  • Finally, they flush the tank by closing the drain valve and removing the hose. They will turn on the cold water supply and wait for the tank to fill itself. Any remaining sediment should flush out through the drain valve. A plumber may need to repeat this process a few times until the water runs clear.
  • Lastly, a professional plumber will turn the power to the hot water heater back on and inspect the heater for leaks. They will pay special attention to the drain valve and other connections.

Again, this process is best left to the experts because they have the experience and knowledge to do it right.

a hot water heater

What Causes Too Much Pressure in Hot Water Heaters?

Some noises that a hot water heater can make result from water pressure issues in the tank. Several issues can cause a pressure problem.

One of the most common culprits is a malfunctioning pressure regulator. This piece of equipment is supposed to maintain proper and consistent water pressure throughout your home’s plumbing system. When the water pressure regulator is faulty, the pressure in your system can become too high and lead to problems.

Next, thermal expansion can also lead to water pressure issues. Thermal expansion occurs when water heats up and expands the plumbing system, which is a normal occurrence. However, if you do not have a sufficient expansion tank installed, the increased volume of water can lead to high pressure in the water heater and other parts of the plumbing system.

Lastly, closed valves in the water supply line can restrict water flow, which causes a buildup of pressure in the water heater. It’s essential to ensure that all valves, such as the main shut-off valve and the inlet and outlet valves of the water heater, are fully open to allow proper water flow.

How To Fix High Water Pressure

While water pressure issues are an annoyance for any homeowner, the good news is that plenty of solutions can solve the underlying problem. For example, repairing or replacing the water pressure regulator may be the answer.

If that is not the issue, installing an expansion tank to better manage thermal expansion may solve the problem. Another potential solution is to verify that all of the valves in your water heater and plumbing system are functioning as they should.

A professional plumber can inspect your system for any issues and identify the root cause of your water pressure problems. Next, they can quickly and effectively repair your system so that you can enjoy perfect water pressure.

Solve Your Water Heater Problems With Professional Help

Water heaters are vital parts of our home that must be regularly maintained to work properly. While it may be confusing to hear noises coming from your water heater, they are likely pointing to a bigger problem that needs to be addressed.

Part of water heater maintenance includes flushing your water heater at least once a year to avoid sediment buildup. A professional plumber can do it easily for you.

Finally, water heater noises could be a result of pressure issues. Contact a plumber to identify the pressure issue and get to the root of the problem.

ABC Can Help With All Your Water Heater Service Needs

Water heater problems can cause large disruptions in your day-to-day life. If you’re experiencing issues, contact ABC Home & Commercial Services. Our licensed professionals will efficiently fix any water heater issues you may be having.

Tom Riggs

Tom Riggs is the Division Manager for Mechanical Services, overseeing sales and operations for HVAC, Plumbing, Electrical, Appliance Repair and Water Quality for all ABC Austin branches. He joined ABC in 2014. Before ABC, he was an HVAC Service Technician, HVAC Comfort Advisor/Sales and Operations Manager. Tom attended Universal Technical Institute. He's an avid outdoorsman and enjoys country living with his wife and two sons.

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