Boiler makes loud banging or knocking noises during firing or shortly after burner shutdown.

Safety: Noisy operation can indicate dangerous conditions. If banging is severe, shut down the boiler and allow it to cool.

• Check circulation: Verify that all Danstoker primary pumps are running and valves are open. Listen for pump cavitation.
• Bleed air: Vent air from high points, radiators, and automatic air vents to remove trapped air.
• Inspect for scale: If the boiler is older or water treatment has been poor, schedule internal inspection. Descale or mechanically clean the heat exchanger as per Danstoker guidelines.
• Adjust firing rate: Temporarily reduce burner firing rate to lessen thermal stress until a permanent fix is implemented.

Ongoing kettling requires professional assessment of water quality, flow rates, and possible descaling.