Model reference
Lennox 12GCSX036-100
HVAC
1 document7 error codes1 service mode
Available documentation
Service Manual
- 12GCS SERIES Service Literature24 pg
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Error codes (7)
CodeMeaning
2 FlashesLockout3 FlashesPressure switch open or closed, or auxiliary limit open.4 FlashesHigh limit or rollout switch open.5 FlashesFlame sensed and gas valve not energized.Fast FlashNormal operation, call for heat.Slow FlashNormal operation, no call for heat.Steady FlashCircuit board self-check failure or ignition/blower control wired incorrectly.Service modes (1)
- Defrost Test Mode (CHP only)["Ensure defrost sensor is closed at 32°F (0°C) or below; if ambient temperature is too high…
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