Napoleon Gas Fireplace: Carbon / soot on glass, logs or firebox

Carbon / soot on glass, logs or firebox on a Napoleon gas fireplace: Black carbon is being deposited on the glass, logs or combustion chamber. Caused by flame impingement or a blocked air shutter.

Homeowner with a gas fireplace problem? Call (647) 657-2977 or book a service call — licensed technicians across Vaughan and the GTA.

Applies to: Napoleon GD70 STARfire direct-vent fireplace (GD70NT-S natural gas, GD70PT-S propane)

Common causes of carbon / soot on glass, logs or firebox

• Flame touching (impinging on) the logs or firebox walls
• Air shutter opening blocked with lint or debris
• Over-firing (wrong manifold pressure or orifice)
• Leaking door gasket or vent joints

How to fix carbon / soot on glass, logs or firebox: step by step

1. Check that every log sits in its correct position per the log placement diagram.
2. Open the air shutter to give the burner more primary air.
3. Verify input rate: measure manifold pressure and confirm orifice size matches the rating plate (NG #35 orifice, propane #51 orifice per parts list).
4. Inspect door gasketing - it must be complete, unbroken and sealing tightly.
5. Check both the 4" and 7" vent liners for holes and confirm every joint is well sealed.
6. On horizontal vent runs, confirm the minimum rise per foot was followed.
7. Clear any lint or obstruction from the air shutter opening.

If the unit shows an error code, look it up: Napoleon Gas Fireplace codes

Models

GD70NT-SGD70PT-S