Onto another repair job and I commonly get asked ‘how do I diagnose a noisy boiler?’ and I thought it might be useful to share before it escalates into a more serious problem or before I get there to solve the issue.
Common causes of a noisy boiler
- Limescale
- Air blockage
- Overheating
- Insufficient water flow
- Faulty thermostat
- Low water pressure
Diagnosing a noisy boiler
Step 1: Identify where exactly the noise is coming from
Is it your boiler that’s making a loud banging noise, or are the unusual sounds coming from a radiator or central heating pipe? If you can hear a creaking noise, it may just be the sound of pipes changing temperature – this is perfectly normal.
Step 2: What type of noise is the boiler making?
Vibrating noises
- Tighten the boiler brackets fixing it to the wall
- If this doesn’t stop the vibrating noises, call a Gas Safe registered heating engineer
Loud banging noises
Could be a faulty thermostat or build-up of debris on the boiler’s heat exchanger – in which case you’ll need a Gas Safe registered engineer to carry out a power flush to remove the sludge in your system.
Gurgling noises
Could be trapped air in the system, low water pressure, or a frozen condensate pipe.
1. Check if the system needs bleeding
Read more about bleeding a radiator.
2. Check the water pressure
If the reading is below 1 bar, this is a sign of low pressure. To increase the pressure to the correct level follow our step-by-step guide.
3. Check for frozen pipes
Find your boiler’s condensate pipe (usually a white overflow pipe outside your home). Thaw it with some warm water (not boiling).
4. Whistling or kettling noises
Kettling is usually caused by limescale on the boiler’s heat exchanger.
Banging or tapping pipes
Could be due to overheating. If you’ve always heard rattling noises, however, it can be due to pipework not being secured properly under the floor.
- Check your boiler’s thermostat by turning off the boiler and cooling the system down
- Once cool, turn it back on again and turn up the thermostat. It should click
- If not, call a Gas Safe registered engineer
Step 3: Help to fix your noisy boiler
If you’re still experiencing problems with your noisy central heating system, don’t hesitate to get in touch with us. One of our Gas Safe Registered engineers could visit your property and examine your system to identify and rectify the issue.
Prepare for the best this winter and let one of our home experts or me handle your repair needs, to get things working again in no time.
Noisy boilers and how to fix them Boiler installation
