Boiler makes loud banging or knocking noises (kettling) during operation

Safety first: Turn off power and allow the boiler to cool completely before touching piping.

• Check pressure and bleed air: Verify system pressure is correct and bleed air from the boiler and radiators.
• Confirm circulator operation: Ensure the pump is running and valves are open to provide adequate flow through the boiler.
• Descale heat exchanger: Persistent kettling usually indicates scale. A professional should perform a chemical flush of the Ruud heat exchanger using manufacturer‑approved descaling solution and pump.
• Install water treatment: Consider adding a scale inhibitor or water treatment system to prevent recurrence.