Main burner goes out during operation

What is going on

Main burner shuts off while running. Note flame behaviour first: goes out with no change, goes ghostly blue first, or shrinks after lighting.

Likely causes

• Pilot not covering thermopile/thermocouple
• Dirty/loose electrical connections
• Pressure drop on activation
• Switch/thermostat wire too long or coiled
• Low thermopile output
• Bad operator coil
• Non-millivolt switch/thermostat or unapproved remote
• Venting problem (ghostly blue flame)
• Spill switch tripping / poor draft (natural vent)

Check in this order

1. Goes out with no flame change check the pilot covers the thermopile and thermocouple.
2. Clean, tighten or replace connections on thermopile, switch, remote and thermostat.
3. Goes ghostly blue before going out treat as a vent problem (see Complete Unit Shutdown guide).
4. Shrinks shortly after lighting check for pressure drop on activation.
5. Check switch/thermostat wire length and gauge are within listed maximums and the wire is not coiled.
6. Test thermopile millivolts and the operator coil resistance.
7. Use only a millivolt wall switch, a millivolt wall thermostat, or a Wolf Steel approved remote (Advantage/Skytech); replace anything else.
8. Natural vent test the spill switch and confirm the unit is drafting and not spilling.

More gas fireplace guides

• Blower noisy, vibrating or rattling
• Carbon / soot buildup (service flowchart)
• Carbon / soot on glass, logs or firebox
• Complete unit shutdown - direct vent
• Complete unit shutdown - natural vent / vent-free
• Delayed ignition of main burner