CTC
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 primary heat exchanger, Sludge in system water, Insufficient flow rate through boiler, Incorrect pump speed setting
How to Fix / Troubleshooting
Safety: Allow the boiler to cool before touching any pipework. Hot water and steam can cause burns.
- Check system pressure and flow: Ensure the system is correctly pressurised and that all radiator valves are open to allow adequate flow.
- Bleed air: Remove air from radiators and high points to improve circulation.
- Adjust pump speed (technician): On models with adjustable pump speed, increase the speed setting to improve flow through the CTC heat exchanger.
- Power flush / chemical clean (technician): If kettling persists, perform a system power flush and chemically descale the primary heat exchanger using products approved by CTC.
- Replace heat exchanger: In severe cases of scaling, replace the primary heat exchanger.
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