HVACopediaGoodman · Furnace
1 flash Lockout - three failed ignition tries
What the control is telling you
The furnace made three ignition tries in one call for heat and never held a flame, so it locked out. The control resets itself after one hour.
Applies to: GMES9, GCES9, AMES9, ACES9, VMES9, VCES9 (single stage, 92% and 96%)
Likely causes
- No gas reaching the burners
- Front cover pressure switch open or its hose or wiring bad
- Bad or misaligned igniter
- Wrong orifices
- Coated, oxidized or loosely connected flame sensor
- Flame lost after lighting: gas supply interruption, lazy flames from wrong gas pressure or restricted flue or air piping, front cover pressure switch opening, weak inducer
Test and repair steps
- Turn off power before repairs.
- Find and fix any gas supply problem.
- Check the front cover pressure switch hose, wiring and contacts.
- Replace or realign the igniter. It breaks easily, so handle it with care.
- Check the flame signal. Sand or clean the sensor if it is coated.
- Check flue piping for blockage, length, elbows and termination. Check inducer performance.
Settings for these units
- Normal status displays (7-segment) · Goodman/Amana GM9S96/AM9S96
- Normal status displays (7-segment) · Goodman/Amana GM9S80/AM9S80
- Normal status displays (7-segment) · Goodman/Amana GM9C96/AM9C96
- Minimum recommended filter size · Goodman/Amana GM9C96/AM9C96
Models that show this code
57 models in Goodman/Amana *MES9 single-stage
Other codes on the same units
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Source: Goodman Service and Troubleshooting GMES9*/GCES9*/AMES9*/ACES9*/VMES9*/VCES9* (RS6612016r3) , Troubleshooting Chart p.51; LED table p.44. Summarized in our own words; check the original manual for your model.
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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.