Applicable Systems
GMVC96 Furnace
GSX14 Condenser
AVPTC Air Handler
Symptoms
Flame sensor not detecting flame during ignition cycle; furnace locks out after multiple attempts; no heat.
Possible Causes
- Flame sensor contaminated with carbon
- Flame sensor wire loose or corroded
- Igniter failing to light burners
- Gas supply interruption
Troubleshooting Steps
- Step 1: Check flame sensor for carbon contamination
Sensor clean (use sandpaper to clean) - Step 2: Verify flame sensor wire connection
Wire connected securely - Step 3: Check igniter operation during call for heat
Igniter glows orange - Step 4: Verify gas supply valve is open
Gas valve open, supply available - Step 5: Clean flame sensor and retry ignition
Furnace ignites and runs normally
How to Reset
Clear by cycling furnace power OFF/ON (kill switch or breaker); retry ignition.
Common Replacement Parts
- Goodman Flame Sensor Kit
- Hot Surface Igniter
Frequently Asked Questions
- Q: How to clean flame sensor?
Remove sensor from burner assembly. Clean metal rod with fine sandpaper or steel wool (not emery cloth). Wipe with clean cloth. Reinstall and test.
Source: Goodman GMVC96 Service Manual
Category: HVAC Residential