Error code reference

Carrier Furnace Error Code 34

Ignition proving failure; if flame is not sensed during the trial for ignition period, the control will repeat the ignition sequence 3 more times before lockout #14 occurs.

SourceCarrier 58DLA/DLX Furnace - Service Manual: Installation & MaintenanceFig. 55 / Service Label

Carrier codes Carrier furnace codes

Diagnostic procedure

The full 34 procedure

Step 1 is visible so you can confirm you are on the right page. The remaining steps, the ones that tell you whether to actually replace a part, unlock with any pass.

MyPros+ · DiagnosticsStep 1 preview

First diagnostic step

Check that flame sensor is not grounded, clean oxide buildup on flame sensor with fine steel wool, verify proper flame sense microamps (0.5 microamps DC min, 4.0-6.0 nominal), check gas valve, manual valve shut-off, defective hot surface igniter, control ground continuity, low inlet gas pressure, inadequate flame carryover, and green/yellow wire connection to furnace sheet metal.

SourceCarrier 58DLA/DLX Furnace - Service Manual: Installation & MaintenanceFig. 55 / Service Label

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More steps, wiring diagram references, and verified part numbers

Includes expected resistance and voltage values, connector pinouts, and supersession notes for replacement parts.

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Where this code is documented

2 manuals in the MyPros+ library document this code for Carrier furnace.

Models covered by the manuals that document this code

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The full 34 procedure

Where this code is documented

Models covered by the manuals that document this code

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