It is common for boilers to make noises as they operate. The most common noise you hear is that of gurgling or bubbling.
But the moment you hear rumbling and banging noises, you should be concerned, those are not common noises you hear in a properly functioning boiler.
There are times that the boiler may make noises while it is turned off.
More often than not, the noise is from the heating pipes rather than the boiler.
However, if you’ve identified the boiler as the source of noise, then you need to figure out what type of noise it is making to determine the possible cause.
Our guide will help you do just that and take the necessary measures to stop the noises.
Why Does The Boiler Make Noise While It Is Off?
There are multiple reasons why your boiler would make noises even when switched off.
- The pump – The boiler works to provide heat to the water, to warm it up. Once the temperature is achieved, it turns off. However, other aspects of the boiler continue to run, such as the pump. The pump will run until the temperature of the water drops slightly below the preset temperature.
- Water movement – Many times the noise produced by a boiler when it’s off is that of water movement. As water moves from one part of the boiler into the pipes or another part, there is some noise produced. This is common and nothing to worry about.
- “Pre-heat” function – In combi boilers with the “Pre-heat” function, the heat exchanger fires up from time to time, even when the boiler is off. This keeps it ready for the moment you do turn it on.
- Short-cycling – As the water starts to cool down, the heat exchanger turns on to cool it down, short-cycling in the process. This is usually due to an issue with the heat exchanger, and it ends up increasing energy bill costs.
How To Fix A Boiler That Makes Noises When Turned Off?
The approach to fixing your boiler depends on the type of noise it makes while switched off.
This is usually caused by limescale build-up.
Limescale is hard to remove, you will need to flush the system out to get rid of it and use a limescale remover.
- Turn the boiler off.
- Turn off the incoming water flow into the boiler also.
- To ensure there is no water, turn on the taps of your home until the system is completely drained, the moment when hot water no longer comes.
- In the cold water storage tank, add the limescale remover. For combi boilers, you need to descale directly by removing the heat exchanger.
- Fill the tank again and let it heat for 3-4 hours. But, open the hot water tap every 15 minutes during that period, letting out about a pint of water each time.
This will flush out the system and get rid of limescale.
There are two main reasons behind banging, either a low flow rate of water or airlock in the pump.
A low flow rate is usually due to a leak, which you will need to identify and fix. For airlock in the pump, you can:
- Turn the main water supply off.
- Turn the taps on throughout your home until water no longer flows through them.
- Flush the toilets also until it has no water.
- Turn the tap off, but leave it just slightly open, so a small amount of water can seep through.
- Turn on the water supply.
- Turn the taps in your home halfway and then completely open.
This should help get rid of any airlock in the pump or system.
Tapping And Clicking
The most common noise is produced when the boiler is off.
This is due to noisy heating pipes.
To fix this, you need first to make sure the pipes are securely in place.
- Check the pipes to see if they are securely latched onto their clips.
- You can add clips to securely put the pipes in place in areas where it is insecure.
- If the pipe is secure throughout, then you may need new pipes fitted to stop the noise. We recommend you get a plumber to do that unless you are familiar with installing pipes.
How To Reduce Boiler Noise In Homes?
If you’ve inspected your boiler and everything is functioning as it should, then you may consider soundproofing your home.
Sometimes the boiler makes noises while performing certain functions or the surrounding material produces noises, and it is no cause for concern.
But these noises can be annoying.
To block them out, you can:
- Get acoustic panels and put them around the boiler cupboard.
- Get carpet tiles installed under the boiler. Most boiler cupboards are made of wood and as the boiler functions, the cupboard vibrates producing noise.
- Install soundproof curtains around the cupboard to stop noise from traveling out.
You don’t have to panic if you hear your boiler make noises even when it is turned off.
Sometimes the boiler continues to function even when turned off, or the noise is due to loose pipes.
But, you must have the boiler checked to identify if the issue is a cause of concern or not.
If you can’t identify the problem yourself, then call in a plumber to not only identify but fix the problem behind the noise.
I’ve been working with technology in one way or the other all my life. After graduating from university, I worked as a sales consultant for Verizon for a few years. Now I am a technical support engineer by day and write articles on my own blog here in my spare time to help others if they have any issues with their devices.