Furnace starts and runs but shuts off on very cold days, sometimes with ice on vent termination.
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: Do not operate the furnace with vent pipes disconnected. Ice-related vent issues can cause flue gas spillage.
Steps to check:
- Inspect outside termination: Look for ice buildup around the PVC vent and intake. Carefully remove ice without damaging the pipes.
- Check vent slope: Inside, verify that horizontal vent runs slope back toward the furnace per Heil installation instructions to allow condensate to drain.
- Temporary mitigation: Clear snow and ice away from the termination area to improve airflow.
When to call a pro: A technician should evaluate vent sizing, routing, and termination to prevent recurring icing and ensure safe operation.
Repair Difficulty
Required Part
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