Error code reference

Carrier HVAC Error Code 26

Invalid heater size: heater ID resistor value read from heater harness connector is invalid for the combination of indoor and outdoor components installed.

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

Carrier codes Carrier hvac codes

Diagnostic procedure

The full 26 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 wiring harness connections to ensure they are secure. Disconnect wiring harness at fan coil control heater header and check for a resistance value greater than 5000 ohms.

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 26 procedure

Where this code is documented

Models covered by the manuals that document this code

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