If your boiler has become unusually loud or temperamental, you’re not alone. Homeowners across Bordon, Whitehill, Liphook, Alton and Farnham often report kettling, banging or short cycling sounds, and many issues can be identified with a few simple checks.
What causes a noisy boiler?
A noisy boiler usually points to water flow issues, trapped air, or limescale buildup. While some problems require a Gas Safe engineer, there are several safe, homeowner‑friendly steps you can take first.
Checking for kettling in a noisy boiler
Kettling sounds like a kettle boiling inside the boiler. It often occurs when limescale builds up on the heat exchanger, especially in harder‑water areas around GU35, GU34 and GU9.
- Check that all radiator valves are fully open.
- Bleed radiators to release trapped air.
- Ensure the system pressure is between 1.0 and 1.5 bar when cold.
If the noise continues, a professional flush or scale reducer may be needed.
Banging or knocking noises
Loud bangs or knocks can be caused by sudden water pressure changes or sticking pumps.
- Make sure your boiler’s pressure isn’t too high.
- Check for partially closed radiator valves restricting flow.
- Listen for pipes knocking against floorboards or joists as they expand.
Persistent banging should be assessed by a qualified engineer to prevent long‑term damage.
Short cycling and inconsistent heating
Short cycling happens when the boiler repeatedly fires up and shuts down. It often points to thermostat issues or restricted circulation.
- Ensure your room thermostat is not near heat sources or in direct sunlight.
- Make sure TRVs in the main heated room are fully open.
- Check that filters and magnetic cleaners (if fitted) are not clogged.
When to call a professional
If you’ve tried the basic checks and your noisy boiler still behaves oddly, it’s best to get help. Professional diagnostics can prevent breakdowns and extend the life of your heating system.
For dependable boiler support, call our team on (01420) 558993.