Model reference

Lennox ML195UH

Name: Lennox ML195UH
Brand: Lennox

Furnace

1 document24 error codes1 service mode

Available documentation

Service Manual

ML195UH Series Units Service Literature60 pg
Covers this model

MyPros+ Max

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M+ Max·Lennox Furnace

1 Flash on my Lennox ML195UH

M+

Flame present with gas valve

From Service Manual 921565, p.17:

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

2.Measure control board supply voltage at test points. Expected: 12 VDC and 5 VDC.

3.Inspect all connectors on the main control for corrosion or backed-out pins.

Part WPW10804018

Electronic control board

Error codes (24)

CodeMeaning

1 FlashFlame present with gas valve de-energized (control 103085).2 FlashesPressure switch closed with combustion air inducer de-energized (control…3 FlashesPressure switch open with combustion air inducer energized (control 103085).4 FlashesPrimary limit switch open (control 103085).5 FlashesRollout switch open (control 103085).6 FlashesPressure switch cycle lockout (control 103085).7 FlashesLockout 8 FlashesLockout 9 FlashesLine voltage polarity incorrect (control 103085).LED OffNo power to control or control hardware fault detected (control 103085).LED OnNormal operation (control 103085).LED1 ALT FAST FLASH / LED2 ALT FAST FLASHImproper main ground or line voltage below 90 volts.LED1 ALT SLOW FLASH / LED2 ALT SLOW FLASHWatchguard 1 hour LED1 FAST FLASH / LED2 FAST FLASHNormal operation LED1 FAST FLASH / LED2 SLOW FLASHMain power polarity reversed LED1 OFF / LED2 ONCircuit board failure or control wired incorrectly (alternate).LED1 OFF / LED2 SLOW FLASHPressure prove switch open (alternate indication on control 100973).LED1 ON / LED2 OFFCircuit board failure or control wired incorrectly.LED1 ON / LED2 ONRollout switch open or 12-pin connector improperly attached.LED1 ON / LED2 SLOW FLASHFlame sensed without gas valve energized.LED1 SLOW FLASH / LED2 FAST FLASHLow flame signal LED1 SLOW FLASH / LED2 OFFPrimary or secondary limit switch open LED1 SLOW FLASH / LED2 ONPressure prove switch open, blocked inlet/exhaust vent, or pressure switch…LED1 SLOW FLASH / LED2 SLOW FLASHPower on

Service modes (1)

Diagnostic Code Recall (Control 103085)Press the push button switch on the integrated control 103085 for less than 5 seconds, then release

Full entry steps, exit procedures, and test sequences are available in Max.

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