Furnace makes loud banging or knocking noises when starting or stopping.

Safety: Allow the system to cool before touching pipes.

• 1. Bleed air: Bleed all radiators and high points to remove trapped air that can cause banging.
• 2. Open valves: Ensure most radiators are at least partially open to allow flow and reduce pressure surges.
• 3. Adjust pump speed: Reduce pump speed slightly to minimize sudden flow changes.
• 4. Secure pipework: Check visible pipes near the Brötje boiler and in accessible areas. Add or tighten pipe clips to prevent movement.