Error code reference

York Furnace Error Code LED on constantly

The control discovered an internal fault during its self-check procedure; all operations cease.

SourceYork P*XU/G9D-UP Furnace - Full Service Manualp. 8

Diagnostic procedure

The full LED on constantly 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 voltage spikes or supply voltage too high or low. Reset the control by breaking line voltage for 30 seconds. If issue persists, replace control.

SourceYork P*XU/G9D-UP Furnace - Full Service Manualp. 8

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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 York furnace.

Models covered by the manuals that document this code

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The full LED on constantly procedure

Where this code is documented

Models covered by the manuals that document this code

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