Model reference

Lennox G61MP-36B-070

Name: Lennox G61MP-36B-070
Brand: Lennox

Furnace

1 document33 error codes2 service modes

Available documentation

Service Manual

G61MP Service Literature76 pg
Covers this model

MyPros+ Max

Diagnose your Lennox G61MP-36B-070.

Step-by-step diagnostics from the service manual
Test values, resistance specs, and wiring references
Verified part numbers when replacement is needed

Start diagnosing

$29/month · Cancel anytime · Or $9.95 3-day pass

M+

M+ Max·Lennox Furnace

1+2 on my Lennox G61MP-36B-070

M+

Low flame current during run mode

From Service Manual 434379, p.31:

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 (33)

CodeMeaning

1+2Low flame current during run mode (Board 100869).1+3Flame sensed out of sequence 2+3Low pressure switch failed open (Board 100869).2+4Low pressure switch failed closed (Board 100869).2+5High pressure switch failed open (Board 100869).2+6High pressure switch failed closed (Board 100869).2+7Low pressure switch opened during ignition trial or heating demand (Board…3+1Limit switch open (Board 100869).4+1Watchguard 4+2Watchguard 4+3Watchguard 4+5Watchguard 4+6Watchguard 4+7Ignitor circuit fault 4+8Low line voltage (Board 100869).5+1Hard lockout 5+2Control failed self check, internal error; control will restart if error…5+3No Earth ground; control will restart if error recovers (Board 100869).5+4Reversed line voltage polarity; control will restart if the error recovers…5+6Low secondary (24VAC) voltage (Board 100869).DS1 Alternating Fast Flash / DS2 Alternating Fast FlashDuring ignitor warm-up only DS1 Alternating Slow Flash / DS2 Alternating Slow FlashWatchguard DS1 Fast Flash / DS2 Fast FlashNormal operation DS1 Fast Flash / DS2 Slow FlashMain power polarity reversed DS1 OFF / DS2 Fast FlashHigh prove switch open; or blocked inlet/exhaust vent; or high prove switch…DS1 OFF / DS2 ONFlame sensed without gas valve energized.DS1 OFF / DS2 Slow FlashLow prove switch open; or blocked inlet/exhaust vent; or low prove switch…DS1 ON / DS2 ONCircuit board failure or control wired incorrectly DS1 Slow Flash / DS2 Fast FlashLow flame signal; measures below 0.23 microAmps DS1 Slow Flash / DS2 ONPrimary, secondary, backup secondary or rollout limit switch open; limits must…

View all 33 error codes

DS1 Slow Flash / DS2 Slow FlashPower on HeartbeatNormal operation PulsePower on

Service modes (2)

Clearing Error Codes (Board 100869)["Short R (2) to (1)
Error Code Review (Board 100869)["Short R (2) to (1) on the control board.","Within 1/2 second, the STATUS LED will stay lit…

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

Related Lennox furnace models

78,000+ service manuals · 160,000+ error codes · 55+ brands

Get Started

$29/month · Cancel anytime · Or $9.95 3-day pass