Water buildup underneath of a water heater

Why Your Boiler Makes Loud Noises

If your boiler is making loud noises, it may be a sign of a problem. Boilers usually make soft noises as they run, but if you start hearing louder noises, it could indicate an issue that could require a boiler repair. If you’ve never heard the noise before, it’s especially important to be concerned.

But why is your boiler making noises? Here are some of the everyday noises made by boilers and what could be causing them:

Banging Noise

If your boiler makes a banging noise, it could be caused by a few different things. First, it could be that the water pressure is too high. This can happen if the boiler isn’t properly vented. Another possibility is that there could be a buildup of sediment in the boiler. This can occur if the water isn’t properly treated or the boiler isn’t used often. Finally, it’s possible that the boiler is damaged and needs to be repaired or replaced.

Humming or Vibrating Noise

This noise is usually caused by something vibrating inside the boiler, such as a loose part or sediment buildup. If the noise is coming from the pipes, it could be due to water pressure that’s too high.

Alternatively, it could be that the boiler is overheating and the noise is coming from the pressure relief valve.

If you hear a humming noise coming from your boiler, it’s essential to check it over and ensure that there is nothing loose inside. If the noise comes from the pressure relief valve, you may need to Bleed your radiators to release some of the pressure.

Whistling Noise

If your boiler is making a whistling noise, it could be due to a buildup of limescale. Limescale is a hard, white substance that can form inside your boiler over time. Limescale buildup can cause your boiler to make a whistling noise as the water is forced through the narrow spaces. You can clean limescale buildup yourself with a descaling solution, or you can call a professional to do it for you.

Rumbling Noise

If your boiler makes a rumbling noise, it could be due to the burner. The burner is the part of the boiler that burns the fuel to create heat. If the burner is dirty or the air supply is restricted, it can cause the burner to make a rumbling noise. You can clean the burner yourself or call a professional to do it for you.

Clanking Noise

If your boiler is making a clunking noise, it could be due to the expansion tank. The expansion tank is a small tank that holds water that expands when heated. If the expansion tank is old or damaged, it can make a clunking noise as the water expands and contracts. You can replace the expansion tank yourself or call a professional to do it for you.

Hissing Noise

If your boiler is hissing, it could be because there’s a leak in the system. This could be a tiny leak, or it could be a larger problem. If you think there might be a leak, you should contact a qualified engineer to take a look.


If you hear any strange noises coming from your boiler, it is important to have it checked out as soon as possible. Even if you think the problem may be small, it is always best to be safe than sorry. A professional can quickly diagnose the issue and make any necessary boiler repairs.

Bromac can provide you with reliable services, including boiler repair in Abbotsford, BC, and nearby areas. Find out more about our plumbing and heating solutions today!

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