Error code reference

Carrier Furnace Error Code 33

Limit circuit fault; indicates a limit, draft safeguard, flame rollout, or blocked vent shutoff switch is open; blower will run for 4 minutes or until open switch remakes, whichever is longer.

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

Carrier codes Carrier furnace codes

Diagnostic procedure

The full 33 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 for dirty filter or restricted duct system, loose blower wheel, defective switch or connections, defective blower motor or capacitor, inadequate combustion air supply (flame rollout switch open), restricted vent, proper vent sizing, or excessive wind.

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 33 procedure

Where this code is documented

Models covered by the manuals that document this code

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