Error code reference

Carrier HVAC Error Code 27

Invalid outdoor unit size: outdoor unit size provided by User Interface is invalid for the fan coil application.

SourceCarrier Fan Coil Units - Service Manual: FB/FE/FF/FH/FV/FX/FZ/PF Seriesp. 15

Diagnostic procedure

The full 27 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 communications wiring to ensure User Interface has established communications with outdoor unit, or select proper size from valid size list at User Interface.

SourceCarrier Fan Coil Units - Service Manual: FB/FE/FF/FH/FV/FX/FZ/PF Seriesp. 15

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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

1 manual in the MyPros+ library documents this code for Carrier hvac.

Models covered by the manuals that document this code

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The full 27 procedure

Where this code is documented

Models covered by the manuals that document this code

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