Boiler vibrates excessively and transmits noise to the wall or pipework during operation.

Safety: Isolate power before tightening any internal components.

• Check wall fixings: Ensure the Defro boiler is firmly secured to the wall bracket and that all locking screws are tight.
• Secure pipework: Add or tighten pipe clips on flow, return, and gas pipes to prevent them from rattling against walls or each other.
• Bleed system: Remove air from the system and ensure correct pressure to prevent pump cavitation noises.
• Fan inspection: If vibration seems to come from the top of the boiler, the flue fan may be unbalanced or worn and should be inspected and possibly replaced by a technician.