FieldBench
Goodman codes

Goodman

HPS

Lockout

High pressure

Outdoor airflow, overcharge, or restriction opened the high-pressure switch.

Walk HPS in Diagnose

6 plates — walk the one on the cabinet

First check

1 Heat rejection first

On Goodman GLXS4B high pressure is outdoor airflow until proven otherwise. Fan running the right direction, coil clean, fins not folded, no recirc over a fence or through a garage. Fan running? Coil dirty? SC vs nameplate on a TXV coil.

Expect: OD fan on, coil clean, discharge air leaving the top/side freely.

The rest of the walkthrough is Diagnose.

On the plates

  • Outdoor fan running? Coil dirty, recirc, bent fins.
  • Subcooling vs indoor TXV sheet. Liquid-line drier / restriction.
  • Do not keep resetting HPS into a locked fan.
  • Mode first. Heat-mode HPS = indoor coil, filter, blower, TXV. Cool-mode HPS = outdoor fan/coil.
  • SC / SH in the running mode. Restriction vs overcharge.
  • Fan running in that mode? A unit stuck in defrost will look like a cool-mode HPS if you are not watching the RV.
  • Fan running? Coil dirty? SC vs nameplate on a TXV coil.
  • OD coil packed. Fan running and correct rotation on 3-phase.

Plates that use HPS

Same number, other makers

HPS on Goodman is not the same code on these plates.