Boiler makes loud banging or knocking noises when starting or during operation.

Safety: Turn off power and allow the boiler to cool before touching any components.

• Check system pressure and air: Ensure system pressure is within the recommended range. Bleed air from radiators and air vents.
• Verify pump speed: If the primary pump has adjustable speeds, set it according to IBC's recommendations for your system.
• Inspect strainers: Clean any system strainers or filters that may be restricting flow.
• Descaling: If the boiler is in a hard water area and noise persists, the stainless steel heat exchanger may require chemical descaling by a professional.

Ignoring kettling can shorten heat exchanger life. Have a technician evaluate flow rates and perform a proper flush/descale if needed.