HVACopediaNapoleon · Gas fireplace troubleshooting
Pilot drops out during operation - natural vent
What is going on
Pilot fails while running on a natural-vent unit - often spillage tripping the spill switch.
Likely causes
- Wrong pilot flame
- Pressure drop on burner activation
- Low thermocouple/thermopile output
- Loose connections
- Spill switch tripping or faulty
- Weak magnet coil
- Spillage / negative pressure in room
- Vent outside spec
- Logs out of place
Check in this order
- Check pilot flame size, pattern and position.
- If the pilot shrinks when the burner lights, check pressure drop on activation.
- Test thermocouple and (single-generator systems) thermopile millivolts.
- Tighten connections on thermopile, spill switch and wall switches.
- Test the spill switch function.
- Test the magnet coil.
- Check for spilling test draft at the spill tube and open a window to relieve negative pressure in the room.
- Confirm vent sizing/height meets local code for natural-vent appliances.
- Check log positions.
Applies to: Napoleon natural-vent (B-vent) gas fireplaces with spill switch (general service manual flowchart)
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Source: Napoleon (Wolf Steel) Service Manual W415-0118, Part 1-3 Troubleshooting, Pilot Failure Flowchart, p.12. Written in our own words; check the manual for your exact model.
For licensed technicians. Gas, electrical and refrigerant work must be done by a qualified, licensed person. Shut off power and gas before servicing, never bypass a safety control, and follow the manufacturer’s manual for the exact model; it and local codes always take priority. HVACopedia is not affiliated with any manufacturer; brand and model names only identify the equipment.