Boiler is very noisy with high‑pitched whine or rumble during operation

Safety first: Turn off power before tightening or removing any components.

• Step 1 – Isolate noise source: Remove the front cover and carefully listen (with the boiler running) to determine if the noise comes from the blower, pump, or piping. Do not touch moving parts.
• Step 2 – Check blower mounting: With power off, ensure the combustion blower is securely mounted and all screws are tight.
• Step 3 – Inspect vent supports: Add or adjust supports on vent piping to reduce vibration and resonance.
• Step 4 – Replace noisy blower: If the blower emits a grinding or high‑pitched bearing noise, replace the combustion blower assembly.

Unusual combustion noises should be evaluated by a technician to ensure safe operation.