Boiler or flue area smells strongly of exhaust or flue gases.
Safety Warning
This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.
If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.
Possible Causes
How to Fix / Troubleshooting
Safety first: Flue gas spillage is dangerous (risk of carbon monoxide). Turn off the boiler and open windows to ventilate. Do not operate the boiler until the issue is resolved.
- Inspect vent connections: Look for loose or disconnected vent joints on the Laars boiler and flue piping.
- Check vent termination: Outside, ensure the vent is not blocked by snow, debris, or nests.
- Avoid competing exhaust fans: Turn off powerful exhaust fans (kitchen, bath) that may create negative pressure until a professional evaluates the system.
When to call a professional: A qualified technician must inspect the venting, test for CO, and check the heat exchanger integrity.
Repair Difficulty
Required Part
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