Model reference

Trane UHMC100ACV4VA

Furnace

2 documents24 error codes5 service modes

Available documentation

Service Manual

Service Facts54 pg
Covers this model

Installation Guide

Installer's Guide56 pg
Covers this model

MyPros+ Max

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M+

M+ Max·Trane Furnace

10 Flash on my Trane UHMC100ACV4VA

M+

Communication error – loss of

From Service Manual 507757, p.49:

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 (24)

CodeMeaning

10 FlashCommunication error 2 FlashExternal lockout 3 FlashPressure switch or inducer error 4 FlashOpen high limit, auxiliary limit, or roll-out limit switch 5 FlashFlame sensed when no flame should be present (flame detect fault).6 FlashEarth ground not detected or poor, reversed line polarity, igniter error, or…7 FlashExternal gas valve circuit error 8 FlashLow flame sensor signal 9 FlashOpen inducer limit ERR 10Ignition means fault ERR 101Y1 relay failure ERR 114Bad or missing personality module ERR 119Temperature sensor failure ERR 139Communication failure ERR 18Internal control failure.ERR 22Soft lockout due to flame lost or ignition retries (10 recycles or 3 ignition…ERR 26High temp limit fault ERR 34Line polarity fault ERR 87Flame detect fault ERR 91Communication fault ERR 93Gas valve fault Solid RedInternal gas valve circuit error (damaged furnace control)Solid Red (continuous reset)Continuous reset caused by an internal error (damaged furnace control).Solid STATUS (Red OFF)24VAC fuse open

Service modes (5)

Contingency Mode (Stand Alone Operation)1
Gas Valve Setup - MAX (100% manifold pressure adjustment)1
Gas Valve Setup - MIN (40% manifold pressure adjustment)1
Unit Test - Simple1
User Interface Access (Service Procedure)1

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

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