How to Fix / Troubleshooting

Safety first: Turn off power before tightening any internal components. Avoid contact with hot surfaces.

Step 1 – Identify noise source: Listen carefully to locate whether the noise comes from the fan, pump, casing, or flue.
Step 2 – Tighten fasteners: Check and tighten screws on the boiler casing, fan mounting, pump brackets, and flue supports.
Step 3 – Check pump for cavitation: Ensure system pressure is adequate and air is bled from the system. Cavitation sounds like gravel in the pump.
Step 4 – Inspect fan: If the fan is rattling or vibrating excessively, check for debris on the wheel and ensure it is securely mounted. Replace the fan if the shaft is loose or bearings are noisy.
Step 5 – Flue supports: Add or adjust supports on long flue runs to reduce resonance and vibration.

Warning: Persistent unusual noises can indicate impending component failure. Do not ignore them.

Boiler is excessively noisy (vibration, humming, or rattling)

Possible Causes