Crown
Kettling / Water Hammer / Expansion Noise
Boiler makes loud banging or knocking noises when starting or 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 buildup in Crown heat exchanger, Rapid temperature changes, Loose piping supports, Air in system
How to Fix / Troubleshooting
Safety: Turn off power and allow the boiler to cool before touching any components.
- Bleed air: Use air vents on the boiler and radiators to remove trapped air that can cause banging.
- Check pipe supports: Inspect visible piping for loose hangers or pipes rubbing against framing. Secure with proper clamps and insulation.
- Descale heat exchanger: Kettling (tea-kettle-like noise) often indicates scale buildup. A professional should chemically descale the Crown heat exchanger using manufacturer-approved procedures.
- Verify system flow: Ensure all valves are open and circulators are functioning to prevent localized boiling.
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