Are you hearing a banging sound somewhere inside your house? Before you start worrying about paranormal activity and letting your imagination run wild with images of ghosts in your walls -the banging sound could very likely be coming from your hot water system.
Hot water heaters often make noise when they need maintenance, or when something is wrong. Common hot water heater sounds include rumbling, crackling, sizzling, ticking, and knocking noises. If your hot water system is making a banging sound, you may need a professional plumber to check your system as soon as possible.
What causes banging sounds in water heaters?
If your water heater makes banging sounds like a hammer on metal, there is likely an issue with your water pressure. This sound is called a water hammer and is made when water is forced to stop or change direction suddenly, creating a pressure surge. Simply put, when a water source is turned off abruptly, the flowing water has nowhere to go and instead rushes in reverse back to the water heater, making the banging sound.
Water hammer can cause severe damage to your water heater. With enough force and pressure, it can cause burst pipes, collapse a flue tube, cause the heater’s shell to expand or even deform the top of the heating tank.
What to do when you hear your water heater making hammer noises
If there is a water hammer noise coming from your water heater, you need to contact a plumber as soon as possible before it does any significant damage or before your hot water heater stops working.
A plumber can fix the water hammer with a water hammer arrestor or a pressure relief valve. They can also check that the water hammering hasn’t damaged anything else that may require repair.
Other hot water heater noises to watch for
A wide range of other water heater noises can indicate that your hot water system needs to be replaced or serviced. Here are a few other noises and their causes you may encounter:
Sizzling, hissing, crackling, popping and rumbling sounds from electric water heaters
Hissing, sizzling, or crackling noises are commonplace in electric water heaters. If you don’t regularly service your heater, sediment can form at the machine’s base.
As the heating element gets hot, it creates steam bubbles underneath the sediment that explode through the surface and often make a hissing or sizzling sound. This can also make a popping sound or rumble as the water heats up. This sediment is easily avoided or fixed with regular water heater servicing and maintenance.
Hissing or sizzling sounds in a gas-powered water heater
A sizzling sound happens in a gas water heater when internal condensation drips on the burners. Condensation could indicate that you have a leaky water heater, and it is a good idea to call a plumber to check these sounds.
Ticking sounds
Ticking sounds are another typical water system sound that are often less sinister than others. A simple change in water pressure can create a ticking sound. Additionally, heat trap nipples are efficiency-boosting additions that help stop the heat from escaping and making a ticking noise. Heat traps are optional additions to your machine, so you can simply remove them if the ticking sound is irritating. Just keep in mind that this will make your machine less energy efficient.
Loose pipe straps can also cause a ticking sound. Designed to keep pipes in place, if the pipe strap is loose, it may make a ticking or clicking noise as the pipe moves around. This is not an urgent issue that requires immediate attention. Tighten the pipes at your next hot water system service.
Screeching sounds
If your hot water system is making noises like a kettle with a screaming, singing or screeching sound, this is cause for concern. High pitch noises generally occur when there is restricted water flow. Often what you are hearing is the pressure relief valve working overtime. If you hear these noises, turn off your heater or gas, and call a plumber immediately.
Humming sounds
Humming noises from your water heater is not usually a reason for concern. Cold water flowing into the tank can make the heating element vibrate, creating a humming sound. This is very normal, but if it is disconcerting or annoying, you can tighten the heating element to stop the vibration.
Service your hot water system to prevent banging noises
The best way to protect your home and hot water system is to regularly maintain your water heater. Regular servicing will find minor problems before they become major concerns that require complex work or could cause water damage to your home.
Don’t ignore your hot water system if it’s noisy. Contact a plumber as soon as you hear any unusual sounds coming from the pipes or systems. The earlier a plumber can assess and repair any issues causing sounds, the easier and more cost-friendly your hot water system will be.
Australia’s #1 hot water service is here to help
If you have a hot water system that needs to be repaired, serviced, or installed, Same Day Hot Water is here to help. We have over 30 years of experience delivering a reliable and friendly service to homes all over the country. Our large team of qualified hot water plumbers is available 24/7 to help get your hot water up and running.
Click here to shop our hot water heaters by type – or – discover our hot water repair and installation services here.