HVACopediaNapoleon · Gas fireplace troubleshooting
Test: gas valve magnet coil and operator coil
What is going on
Valve coil resistance / hold-in checks for Robertshaw and SIT 820 Nova valves.
Likely causes
- Failed valve magnet (pilot) coil
- Failed valve operator (main) coil
Check in this order
- Robertshaw magnet coil remove wires from operating head (except magnet coil wire), ohmmeter black lead to TP, red to TP/TH - 9 to 11 ohms.
- Robertshaw operator coil remove all wires, same lead placement - 1.5 to 1.7 ohms.
- SIT 820 Nova magnet coil resistance too low to read, so do a hold-in test - one mV lead on the thermocouple capillary, other on the solder button under the valve; light pilot and hold the knob until 6 mV (standard) or 4.2 mV (vent-free), then release. Pilot must stay lit or replace the valve.
- SIT 820 Nova operator coil remove all wires, black lead to TP, red to TH - 2.25 ohms.
- Reconnect the magnet coil wire to terminal 1 after testing; replace the valve if out of spec.
Applies to: Napoleon gas fireplaces - direct vent, natural vent and vent-free (general service manual)
More gas fireplace guides
Take it to the job
All guides, error codes and tips work offline in the HVACopedia app.
Source: Napoleon (Wolf Steel) Service Manual W415-0118, Part 5 Testing & Adjustments, Testing: Function, p.36-39. 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.