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Napoleon · Gas fireplace troubleshooting

Pilot will not stay lit - direct vent

What is going on

Pilot lights but will not hold on a direct-vent unit.

Likely causes

  • Loose thermocouple
  • Dirty thermocouple tip
  • Low thermocouple output
  • Weak valve magnet coil
  • Undersized gas supply line

Check in this order

  1. Tighten the thermocouple at the valve.
  2. Clean any buildup off the thermocouple tip so it sits fully in the flame.
  3. Measure thermocouple millivolts (spec 20-30 mV open circuit, 10-15 mV closed circuit).
  4. Test the valve magnet coil (Robertshaw 9-11 ohms; SIT 820 Nova: hold-in test).
  5. Check the supply line size against local code and replace if undersized.

Applies to: Napoleon direct-vent gas fireplaces (general service manual flowchart; applies to GD70NT-S/GD70PT-S)

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Source: Napoleon (Wolf Steel) Service Manual W415-0118, Part 1-3 Troubleshooting, Pilot Not Holding Flowchart, p.2. 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.