Gas fireplace troubleshooting guides

58 guides. Troubleshooting guides for gas fireplace equipment. Each one lists the likely causes and what to check, in order.

All brands (8)

• Flameworks millivolt valve: pilot outage or burner will not come on
  Fireplace or heater with a Flameworks millivolt or 3 V gas valve: pilot will not stay lit, or the main burner will not come on.
• Maxitrol GV60 remote valve: fireplace will not light or respond
  Fireplace with a Maxitrol GV60 battery-powered remote valve: no response, beeping, pilot or burner problems.
• Proflame (SIT DFC): fan, AUX outlet, split flow or OFF command not working
  Proflame GT system with Fan Control Module: fan or AUX outlet not responding, split-flow burner not switching, or the fireplace will not shut off from
• Proflame (SIT DFC): pilot lights but main burner will not light or drops out
  Proflame system: pilot proves but the main burner will not come on, will not stay on, or does not modulate.
• Proflame (SIT DFC): pilot will not light or DFC locks out
  Fireplace with SIT Proflame electronic ignition (DFC board, 880/885/886 valve, GT remote): no pilot, or the DFC goes into lockout.
• SIT 820 Nova millivolt valve: main burner will not come on or will not cycle
  Pilot is fine but the burner will not light with the switch/thermostat, lights intermittently, or the flame looks wrong.
• SIT 820 Nova millivolt valve: pilot will not light
  Standing-pilot fireplace with an SIT 820 Nova millivolt valve: no pilot.
• SIT 820 Nova millivolt valve: pilot will not stay lit
  The pilot lights while the knob is held but goes out when released, or drops out later.

Heat & Glo (7)

• DSI fireplace: burner lights but will not stay lit
  The burner lights and then goes out because the module does not prove flame (flame rectification).
• DSI fireplace: ignitor sparks but burner will not light
  Spark is present but the burner never lights; on RAM 1MC1 modules it sparks for 4 s (-01) or 7 s (-05) then locks out.
• DSI fireplace: ignitor will not spark
  Heat-N-Glo direct spark ignition fireplace: no spark at the electrode when the fireplace is switched on.
• Fireplace with PVK-80 power vent: flames lifting or jumping
  Flame tuning on a Heat-N-Glo DSI fireplace with the PVK-80 power vent; also covers the short delay before ignition.
• HSI fireplace: flame comes on but will not stay lit
  The burner lights on a hot surface ignition unit but drops out.
• HSI fireplace: hot surface ignitor will not glow
  Heat-N-Glo hot surface ignition fireplace: the ignitor does not heat up. It will not glow without 24 VAC on the 24 V side of the module.
• HSI fireplace: ignitor glows but no flame
  The hot surface ignitor heats up but the burner does not light.

Lennox (3)

• Fireplace does not respond to the remote - Lennox Elite LDV
  Pressing ON/OFF on the hand remote does nothing.
• First start-up: pilot slow to light - Lennox Elite LDV
  On the first start the pilot does not light right away.
• Sooting or flame too blue - Lennox Elite LDV
  Long orange flames with black tips and soot on the glass or near the vent cap, or flames that stay blue and see-through.

Napoleon (40)

• Blower noisy, vibrating or rattling
  Fireplace convection blower makes noise.
• Carbon / soot buildup (service flowchart)
  Sooting in the firebox - work through altitude, air shutter, venting, orifice and impingement.
• Carbon / soot on glass, logs or firebox
  Black carbon is being deposited on the glass, logs or combustion chamber. Caused by flame impingement or a blocked air shutter.
• Complete unit shutdown - direct vent
  Burner (and often pilot) shut down; flame goes blue and see-through before going out - a venting/recirculation fault.
• Complete unit shutdown - natural vent / vent-free
  Unit shuts down; flame goes blue/ghostly before going out.
• Delayed ignition of main burner
  Main burner lights late or with a roll-out/puff.
• Exhaust fumes smelled in room / occupants get headaches
  Combustion fumes are entering the room. The fireplace is spilling. Can also be odour from first-fire paint curing.
• Flames always too large or too small / carboning (over- or under-fired)
  Flame size is consistently wrong and/or carbon forms. The unit is over-fired or under-fired - check gas pressures.
• Main burner flame is blue, lazy and transparent
  Flame looks ghostly blue and see-through - a sign the burner is starved of combustion air / flue gases are recirculating.
• Main burner goes out and pilot goes out
  Both burner and pilot extinguish during operation. Check venting first, then follow the 'main burner goes out; pilot stays on' checks.
• Main burner goes out during operation
  Main burner shuts off while running. Note flame behaviour first: goes out with no change, goes ghostly blue first, or shrinks after lighting.
• Main burner goes out; pilot stays on
  Pilot remains lit but main burner drops out - usually low thermopile voltage reaching the valve.
• Main burner low flame
  Burner fires but flame is smaller than it should be.
• Main burner will not light - direct vent / vent-free
  Pilot is on but the main burner will not come on.
• Main burner will not light - natural vent
  Pilot is on but main burner will not fire on a natural-vent unit.
• Odour from fireplace
  Smell when the fireplace runs.
• Oil-canning (popping/banging metal noise)
  Metal pops or bangs as it heats/cools. The sooner after ignition it happens, the closer it is to the heat source.
• Pilot drops out during operation - direct vent
  Pilot fails while the unit is running on a direct-vent fireplace.
• Pilot drops out during operation - natural vent
  Pilot fails while running on a natural-vent unit - often spillage tripping the spill switch.
• Pilot drops out during operation - vent-free
  Pilot fails while running on a vent-free unit - ODS may be sensing low oxygen.
• Pilot flame appearance diagnosis and adjustment
  Read the pilot flame to find the cause; correct flame covers 3/8"-1/2" of the thermocouple/thermopile.
• Pilot goes out when the gas knob is released
  Pilot lights but will not stay lit after the knob is let go. Note: the valve has an interlock that will not let the pilot relight until the thermocoup
• Pilot goes out while standing (main burner OFF)
  Pilot drops out on its own while the main burner is off, often when another appliance or the burner fires - suspect undersized gas piping.
• Pilot lit, no gas to main burner (knob on HI, switch/thermostat ON)
  Pilot is burning and controls are calling but the main burner will not come on.
• Pilot will not light
  No pilot ignition when the piezo push button is pressed.
• Pilot will not light (service flowchart)
  Step-by-step check when the pilot will not ignite. Same flowchart for direct vent, natural vent and vent-free units.
• Pilot will not stay lit - direct vent
  Pilot lights but will not hold on a direct-vent unit.
• Pilot will not stay lit - natural vent
  Pilot will not hold on a B-vent/natural-vent unit; includes the spill switch circuit.
• Pilot will not stay lit - vent-free
  Pilot will not hold on a vent-free unit with ODS pilot.
• Remote control: blank display or cannot turn fireplace off
  Transmitter display blank, or transmitter will not shut the fireplace off.
• Remote control: pairing / code setting and multiple remotes
  How to code the hand-held to the receiver; receiver gives a single (possibly faint) beep when it learns the code.
• Remote control: receiver will not turn fireplace on, shuts off by itself, or turns on unexpectedly
  Receiver-side remote problems.
• Test: door gasket seal (paper test)
  Quick check of door gasket sealing.
• Test: gas inlet and manifold pressure
  Reference pressures and method for millivolt valves.
• Test: gas valve magnet coil and operator coil
  Valve coil resistance / hold-in checks for Robertshaw and SIT 820 Nova valves.
• Test: spill switch and wall switch/thermostat wiring
  Isolate a bad switch from bad wiring, and check spill switch continuity.
• Test: thermocouple and thermopile millivolts
  Generator output specs.
• Venturi / air shutter adjustment
  Set flame colour; may need adjusting for fuel, vent configuration and altitude.
• Wall switch OFF but main burner comes on when gas knob turned ON
  Main burner lights from the knob alone even though the remote wall switch is off.
• White or grey film on glass, logs or firebox
  A white/grey haze builds up on the glass and inside surfaces. This is sulphur from the fuel depositing on the surfaces.

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.