FieldBench
Goodman codes

Goodman

9 flash

Lockout

Polarity / ground

L1/N or chassis ground. Sister to rapid flash on some revisions.

Walk 9 flash in Diagnose

Sign in for the next measurement

First check

1 Hot and neutral at the IFC, not the disconnect

On Goodman GMSS96 polarity/ground is measured at the board. A correctly landed disconnect with a swapped whip at the IFC still throws this. Hot/neutral at the IFC.

Expect: L1 hot, N neutral, ~120 VAC L1 to N, ~0 VAC N to ground.

The rest of the walkthrough is Diagnose.

On the plates

  • Hot/neutral at the IFC.
  • Burner box to IFC ground screw.

Plates that use 9 flash

Same number, other makers

9 flash on Goodman is not the same code on these plates.