Model reference
Lennox G50UHI-36B-090
Furnace
1 document10 error codes2 service modes
Available documentation
Service Manual
- G50UHi Series Service Literature35 pg
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Diagnose your Lennox G50UHI-36B-090.
- Step-by-step diagnostics from the service manual
- Test values, resistance specs, and wiring references
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Error codes (10)
CodeMeaning
LED1-AlternatingFastFlash / LED2-AlternatingFastFlashDuring ignitor warm-upLED1-AlternatingSlowFlash / LED2-AlternatingSlowFlashWatchguardLED1-FastFlash / LED2-FastFlashNormal operation, signaled when heating demand initiated at thermostat.LED1-FastFlash / LED2-SlowFlashMain power polarity reversedLED1-Off / LED2-SlowFlashProve switch open, or blocked inlet/exhaust vent, or prove switch closed prior…LED1-On / LED2-OnRollout switch open or low voltage pin connector improperly attached.LED1-On / LED2-SlowFlashFlame sensed without gas valve energized, or rollout switch open, or low…LED1-SlowFlash / LED2-FastFlashLow flame signalLED1-SlowFlash / LED2-OnPrimary or secondary limit switch openLED1-SlowFlash / LED2-SlowFlashPower on, normal operationService modes (2)
- Blower Speed Adjustment (Blower Control Module)1
- Fan-Off Time Adjustment (DIP switches)Access S1 DIP switches on SureLight integrated control board
Full entry steps, exit procedures, and test sequences are available in Max.
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