Model reference

Lennox G26Q3-75

Furnace

1 document14 error codes

Available documentation

Service Manual

G26 Series Service Literature53 pg
Covers this model

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LED-OFF on my Lennox G26Q3-75

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Control failure or power failure or

From Service Manual 872324, p.16:

1.Access service mode to confirm the active fault code and read stored error history.

2.Measure door lock assembly resistance across PTC terminals. Expected: ~200 ohms cold.

3.Inspect strike and latch alignment. A misaligned strike prevents the switch stack from closing.

Part W10810403

Door lock assembly

Error codes (14)

CodeMeaning

LED-OFFControl failure or power failure or hard lockout (G776 ignition control, -1 and…LED-SLOW_FLASH_1ON_5OFFControl retry period LED-STEADY_ONNormal operation (G776 ignition control, -1 and -2 models).LED1-ALT_FAST_FLASH/LED2-ALT_FAST_FLASHImproper main ground or line voltage below 75 volts; OR broken ignitor; OR open…LED1-ALT_SLOW_FLASH/LED2-ALT_SLOW_FLASHWatchguard LED1-FAST_FLASH/LED2-FAST_FLASHNormal operation signaled when heating demand initiated at thermostat.LED1-FAST_FLASH/LED2-SLOW_FLASHMain power polarity reversed LED1-OFF/LED2-SLOW_FLASHPressure switch open or has opened 5 times during a single call for heat; OR…LED1-ON/LED2-ONCircuit board failure or control wired incorrectly.LED1-ON/LED2-SLOW_FLASHRollout switch open OR 9-pin connector improperly attached.LED1-SLOW_FLASH/LED2-FAST_FLASHLow flame signal LED1-SLOW_FLASH/LED2-OFFFlame sensed without gas valve energized.LED1-SLOW_FLASH/LED2-ONPrimary or secondary limit open; limit must close within specified trials/time…LED1-SLOW_FLASH/LED2-SLOW_FLASHPower on, normal operation; also signaled during cooling and continuous fan.

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