Addressing Common Water Heater Noises

Do hot water heaters make noise, you might ask, and if you hear an odd sound—whether it’s a pop, hum, or hiss—pay attention to what’s happening inside. Some of these sounds are normal, but some may indicate it’s time for a bit of maintenance or repair. 

Recognising what each noise means can save you time, money, and stress down the line. In this guide, let’s break down the most common water heater noises, explore what might be causing them, and discuss how to address each.

Some of the common water heater noises and how to fix them

Popping or Rumbling Noise

Popping or rumbling sounds are some of the most common noises you’ll hear from a water heater. This water heater noise popping is usually caused by sediment build-up in the tank.

Over time, minerals in hard water settle at the bottom of the heater. When the water heats up, steam bubbles can get trapped under this sediment, which leads to the popping sound you hear.

How to Handle Popping or Rumbling Sounds

• Flush the Tank: Draining and flushing the water heater once or twice a year will remove the sediment that causes these noises.
• Use a Descaling Solution: In areas with very hard water, descaling products can help break down stubborn limescale deposits.

Humming Noise

If you hear a low humming noise from your water heater, it’s likely due to a loose heating element.

When a water heater makes a humming noise, this vibration doesn’t usually cause any harm, but tightening the element can eliminate the noise. Securing it also helps keep the water heater running at its best.

How to Handle Humming Sounds

• Check and Tighten the Heating Element: If you’re comfortable, turn off the power and tighten the element to secure it in place.
• Adjust Water Flow: Lowering the water flow can help reduce the vibrations responsible for the humming.

Sizzling or Hissing Noise

A sizzling or hissing noise often means that sediment has built up over the heating element in an electric water heater. This can create hot spots that make trapped water steam and hiss.

In gas hot weater systems, this noise can also happen when condensation drips onto the burners.

How to Handle Sizzling or Hissing Sounds

• Flush the Heater: Flushing the water heater can help remove sediment build-up, which should reduce hissing noises.
• Check for Leaks: Make sure there are no leaks dripping onto the heater, especially with gas water heaters, as this can also cause hissing sounds.

Banging or Hammering Noise

If your hot water heater is making noise when water is off, it’s likely due to “water hammer”—a pressure surge that occurs when water flow is suddenly stopped or redirected.

This pressure can sometimes be strong enough to damage pipes or even the water heater itself. If left unchecked, water hammer can lead to costly repairs down the line.

How to Handle Banging or Hammering Sounds

• Install a Water Hammer Arrestor: This device absorbs the pressure shock, helping to reduce or eliminate the banging noise.
• Reduce Water Pressure: Lowering the water pressure in your home can relieve stress on the pipes, which helps to reduce water hammer.

Ticking or Clicking Noise

Pipes expand and contract with changes in water temperature and that often results in ticking or clicking sounds. While this noise is usually harmless, it can become irritating over time. Regularly checking your system and making small tweaks can usually stop these sounds and keep the heater working quietly.

How to Handle Ticking or Clicking Sounds

• Insulate the Pipes: Adding insulation around the pipes can help reduce ticking sounds by limiting how much they expand and contract.
• Adjust Valves: Ensure all valves connected to the heater are fully open to help prevent unnecessary clicking noises.

When to Call Professional Help

If your water heater makes strange sounds and basic fixes like flushing or adjusting valves haven’t helped, it’s probably time to call a professional. Letting these sounds go unchecked can cause more serious problems later. Professionals have the tools and expertise to find and fix these issues and keep your water heater safe and working well.

In general, call a professional if you notice:

• Persistent noises that continue after basic maintenance
• Any water pooling around the heater or visible leaks
• New, sudden, or high-pitched noises
• Unusual sounds coming from gas water heaters
• Banging sounds from water hammer that don’t improve with lower water pressure

Facing Water Heater Troubles? Ausco Plumbing is Here to Help

Strange water heater noise can be frustrating, but with the right help, most problems can be solved. At Ausco Plumbing, we provide expert hot water heater repair services in Lake Macquarie and hot water heater repair services in Newcastle to help you get rid of these annoying sounds and keep your water heater in top condition. Our friendly, experienced team is just a call away and ready to help with any water heater issues you’re facing.