Thermona
Heat Exchanger Kettling / Localised Boiling
Boiler makes loud banging or knocking noises (kettling) during operation.
Advertisements
Safety Warning
This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.
If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.
Advertisements
Possible Causes
Limescale build-up in Thermona primary heat exchanger, Sludge in primary circuit, Low flow rate due to partially blocked filter, Incorrect pump speed setting
How to Fix / Troubleshooting
Safety: Noisy boiling can indicate high local temperatures. Avoid touching hot pipes or the heat exchanger.
- Check system pressure and flow: Ensure the pressure is correct and all radiator valves and isolation valves are open to allow good circulation.
- Bleed air: Remove air from radiators and the boiler's automatic air vent to improve flow.
- Clean filter (engineer level): If a Thermona system filter or magnetic filter is installed, isolate and clean it thoroughly.
- Descale/flush (engineer level): A technician should chemically descale the primary heat exchanger or power flush the system using appropriate inhibitors and cleaners approved for Thermona boilers.
- Adjust pump speed: Set the pump to a higher speed if the system is large and flow is marginal.
Advertisements
Repair Difficulty
Hard
4/5
Required Part
Primary Heat Exchanger
Check Price on Amazon
We may earn a commission from links on this page.
Advertisements