Goodman codes

Goodman

No shift

Lockout

RV / mode

Pressures do not swap with a heat/cool changeover.

Walk No shift in Diagnose

Sign in for the next measurement

First check

1 Confirm O/B is energized the way THIS outdoor expects

Most US splits energize O in cool. Some Rheem/Ruud energize B in heat. Read the Goodman GSZ14 diagram, not a generic heat-pump card. O vs B at the stat and at the defrost board jumper. Goodman boards are not automatically Carrier O-on-cool.

Expect: Correct 24 V at the solenoid for the mode that is failing.

The rest of the walkthrough is Diagnose.

On the plates

  • O vs B at the stat and at the defrost board jumper. Goodman boards are not automatically Carrier O-on-cool.
  • RV solenoid 24 VAC during the commanded shift. Tap test / pressure swap.

Plates that use No shift