Furnace makes loud banging or knocking noises when starting or stopping

Safety: Noise may indicate stress on components; inspect before continued use.

• Bleed system: Remove air from radiators and high points to reduce sudden flow changes.
• Adjust pump speed: If possible, reduce the pump speed to minimise hydraulic shocks.
• Secure pipework: Clip loose pipes and add cushioning where they pass through walls.
• Check temperature ramp: In the controller, reduce maximum flow temperature or enable soft-start features if available.