Boiler emits a strong burning or electrical smell during operation

Safety first: If you see smoke or suspect an electrical fire, shut off power at the breaker and call emergency services. Do not ignore strong burning smells.

• Initial run after long off period: A mild burning dust smell can be normal the first time the boiler runs each season. It should dissipate within an hour.
• Inspect circulator motors: Check for very hot pump casings, discoloration, or noise, which may indicate a failing motor.
• Check wiring and insulation: Look for browned or melted wire insulation, especially near the burner, flue, and control board. Tighten any loose connections.
• Examine flue and nearby materials: Ensure no plastic, wiring, or combustible materials are touching the flue pipe.
• Call a technician: Persistent or strong burning or electrical odors require professional diagnosis.