How to Troubleshoot and Fix a Noisy Boiler

May 11, 2023 | News

Boiler noise

Are you being kept awake at night by the loud banging, whistling or vibrating noises coming from your boiler? Boilers play an essential role in keeping our homes warm and providing hot water, but when they start making strange noises, it can be a cause for concern. Fortunately, most of the common boiler noises can be diagnosed and fixed without calling in a professional.

In this guide, we’ll walk you through the different types of noises your boiler might be making and what they mean. We’ll also provide you with practical steps to help diagnose and fix the problem, as well as tips to prevent it from happening again.

Common Noises from Boilers

Before we dive into the causes of different boiler noises, let’s take a look at the most common ones you might be hearing:

  • Humming
  • Whistling or kettling
  • Vibrating
  • Gurgling
  • Loud banging
  • Clicking
  • Tapping
  • Whooshing

Why is My Boiler Making a Loud Noise?

There are several reasons why your boiler might be making a loud noise. Here are some of the most common causes:

Low Water Pressure: Low water pressure can cause your boiler to make a humming noise.

Limescale Build-Up: When limescale builds up inside your boiler, it can restrict the flow of water and cause it to become trapped around the boiler’s heat exchanger. This can make the exchanger overheat, expand and produce steam – which creates a whistling sound.

Clogged Flue or Air Intake: A clogged flue or air intake can cause a vibrating noise in your boiler.

Trapped Air: If your boiler is sounding like a kettle boiling water, it usually means there is air trapped inside the heating system.

Now let’s look at each type of noise in more detail and how to fix it:


Humming is a common boiler noise and usually relates to the pump. The pump makes a humming noise, so it’s a good idea to check this first. If the pump is warm, it’s likely to be due to normal operation. However, if it’s very hot, it could indicate a seized part. In this case, you’ll need to call a qualified boiler engineer to deal with the issue.

Whistling or Kettling

Whistling, or ‘kettling’ as it is also known, is a common boiler noise that usually means there is air trapped inside the heating system. One way to remove the air is by bleeding your radiators. Follow our handy step-by-step guide on how to bleed a radiator.

Another common cause of boiler kettling is the build-up of limescale. When limescale builds up, it restricts the flow of water, causing it to become trapped around the boiler’s heat exchanger. This can make the exchanger overheat, expand and produce steam, which creates a whistling sound. To treat limescale, introduce an inhibitor (to reduce limescale) into your boiler system to break down the collected sludge. You might also fit a filter to catch any debris travelling around the system. If you have released trapped air from the system and are still concerned your boiler is kettling, call a qualified engineer to inspect your boiler.


Vibrating sounds in your boiler are typically due to a bracket coming loose. Check the brackets around your boiler, and tighten them yourself with a screwdriver. If the vibrating noises don’t stop, call a certified engineer who will be able to help diagnose the cause.


Gurgling sounds come down to a few potential culprits. The first, and the most easily

fixable, is a radiator bleed. Leaving trapped air in the system could lead to bigger problems, so it’s best to correct the issue swiftly. In the winter months, the condensate pipe can freeze, leading to gurgling noises. To thaw a frozen condensate pipe, pour warm water over it. Never use boiling water as this can cause the pipe to crack. If low water pressure is causing your pipes to gurgle, use your boiler’s manual to determine the precise reading, but as a general rule, if the reading is below 1 you’ll need to increase the pressure.

Loud Banging

If you hear loud banging when your boiler is turned on or when the hot water is running, it could be due to an airlock in the heating pump. You can usually release a little air by adjusting the bleed screw that’s fitted to the pump, which in turn can relieve the banging.


Clicking usually means ignition failure. Check your boiler is firing up properly. If it isn’t, the noises you’re hearing could be your boiler trying, and failing to ignite.

Tapping If your central heating pipes are making tapping sounds while switched off, the issue will require an expert engineer to investigate the problem.


Whooshing noises coming from your boiler are either due to air intake pipe blockages or air filter blockages. By putting your hand over the entry point of the air intake pipe, you’ll quickly notice if you can feel any air. If you can’t, then it’s likely the pipe is blocked. If you can feel movement, then the air filter is probably blocked. Both problems require a certified engineer or boiler specialist to inspect your boiler and fix the issue.

How to Keep Your Boiler Quiet

Regular maintenance can be the difference between proactively preventing a problem or catching it early. Here are some quick and simple checks you can make to keep your boiler working as it should:

  • Regularly check your boiler for leaks, and inspect pipes for cracks and damage.
  • Fit a filter to catch sludge or debris – ask your qualified boiler engineer to clean the filter during every service.
  • Inspect the pump to make sure it hasn’t seized.
  • Examine the heat exchanger for limescale build-up.
  • Regularly check your boiler’s pressure and flow rate.

Book a boiler quote

Call our specialists on 020 8395 8616 or fill in our booking form.

If Your Boiler Noises Persist

If your boiler noises persist and you’re unable to identify the underlying cause, we recommend getting in touch with a professional boiler engineer. Old boilers or boilers that are out of warranty can make all sorts of sounds, and long term damage can occur without inspection. YourRepair is on hand to fix and service boilers. We are the boiler experts and as specialists, we can help.

In conclusion, identifying and fixing a noisy boiler can be done with a little bit of effort and some basic know-how. By keeping up with regular maintenance checks and following our troubleshooting guide, you can keep your boiler quiet and efficient. If you’re still experiencing problems, don’t hesitate to contact a professional boiler engineer.

Open chat
How can we help?