FieldBench

Goodman

GMSS92

Furnace · Single-stage · 92% AFUE · LED flash

Merit-style Goodman 92% single-stage with the 1–9 red LED chart. Still condensing — collector and PVC exist. Same flash meanings as GMSS96; the secondary / vent load is the 92% cousin, not an 80% chimney.

Not GMSS96 (96% — same flashes, bigger secondary / different trap load). Not GMS80 (80% metal vent — 3-flash is a chimney). Not GR9S96 (7-seg EE-codes).

Walk this in Diagnose

This plate

AFUE
92% condensing · still a collector and PVC
Display
Red LED 1–9 flash — same chart as GMSS96
Staging
Single-stage · one PS

This board

Single-stage LED IFC (92%)

  • 1 lockout, 2 PS closed, 3 PS open, 4 limit, 5 flame valve off, 6 rollout, 7 low flame, 8 igniter, 9 polarity.
  • Rapid flash = reversed polarity, not a high count.
  • 3-flash is still trap / PVC / inducer — this is not GMS80.

Sequence

  1. W. Inducer → one PS → HSI → valve → flame → blower. 92% collector can still drown.

Faults on this IFC

  • 3 flash

    PS open

    lockout

    Draft. 92% trap / PVC / inducer.

    • Trap and collector first. 92% still makes condensate.
    • Inducer 120 VAC, hose on the only tap, PVC termination.
  • 4 flash

    Limit

    warn

    Airflow.

    • Filter, speed tap, coil.
  • 7 / 8 flash

    Flame / igniter

    warn

    Rod or HSI.

    • µA, nitride ohms, 120 VAC during trial.

Workflows

3-flash: 92% or 96% or 80%?

Before you cut the wrong vent.

  1. Plate GMSS92 = 92% condensing. Trap/PVC. Stay here.
  2. Plate GMSS96 = same flashes, 96% secondary. Use that chart if you need the 96% trap notes.
  3. Plate GMS80 / GMES80 = metal vent. 3-flash is a chimney. Wrong page.

Test points

Single PS
NO. Closed only with inducer up.

Gotchas

  • Techs treat every Goodman 3-flash as ‘96% trap.’ On GMS80 that wastes the call. On GMSS92 the trap is real — just a 92% secondary.

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