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Models
Goodmanfurnace

GMSS92

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).

Diagnose this modelInstall notesBoard cross-refField wiring

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.

Active code repeats until power is pulled.

Universal swap

Read the silk

Same older Goodman LED family as GMSS96. Silk → ICM2811 or ICM280. 50A55 only if it is already a WR 50A5x.

Silk: PCBBF110 · PCBBF112 · PCBBF123 · B18099-26 · B18099-13

White-Rodgers

  • 50M56U-843

    If the dead board is on the 50M56U single-stage HSI list.

ICM

Honeywell

  • S9200U1000

    S9200U1000 list includes B18099-xx, 102077-xx, and 50A55-843. Same single-stage PSC job as those silks.

  • GR9S96 9-speed EE card. ComfortBridge.

After you pull the dead card

  1. 1Kill power. Photograph the silk-screen part number on the dead board before you pull it.
  2. 2Match staging (1 vs 2 vs modulating), igniter (carbide / nitride / spark), and motor (PSC / ECMx / 9-speed tap / serial VS).
  3. 3Set heat-off delay and any 80+/90+ jumper to the door card. Prove one full try and flame µA before you leave.

Field wiring

Written landings for Goodman GMSS92. Not a factory schematic.

Furnace · single-stage 24V
R / C / W / Y / GGas furnace

Conventional single-stage furnace IFC. One W. Cool Y passes through to the outdoor. No ComfortBridge, no ABCD, no W2.

Written circuit description only — FieldBench does not redraw maker schematics. Example: R to W closes on a heat call; verify 24V at W1 before you change the IFC.

Open manufacturer PDF

Heat sequence

  1. 1Power. L1 / N → IFC → transformer → R120V in, 24V out
  2. 2Call. Stat W → IFC W~24 VAC
  3. 3Draft. IFC → inducer → PS close120V motor, 24V prove
  4. 4Ignite. IFC → HSI120 VAC
  5. 5Gas. IFC → valve~24 VAC
  6. 6Flame. Rod → IFCµA DC
  7. 7Blow. IFC → heat speedAfter flame prove

This indoor

92% flash cousin. Same 24V strip.

24V single-stage heat

Door card is one-stage. Twin terminal empty unless the job is actually twinned.

Wall thermostat

Single-stage heat/cool. W2 from a leftover two-stage stat does nothing useful.

  • R24V hot from the IFC24V
  • CCommon24V
  • WHeat24V
  • YCool — also starts the outdoor24V
  • GFan24V

Furnace IFC

Transformer lives here. Y out to the outdoor contactor. TWIN empty on a standalone.

  • RHot to the stat24V
  • CCommon — must reach the outdoor24V
  • WHeat call24V
  • YCool in / cool out24V
  • GBlower24V
  • TWINEmpty unless twinned24V

Landing

  • 24VIFC Rstat R

    ~24 VAC hot

  • 24VIFC Cstat Coutdoor C

    Common

  • 24VStat WIFC W

    Heat. Stays in this cabinet.

  • 24VStat YIFC Youtdoor Y

    Cool / contactor

  • 24VStat GIFC G

    Fan. Does not go outdoors.

IFC harness — single-stage heat

After W arrives. This is the gas train, not the thermostat strip.

Transformer + fuse

120V primary. 24V secondary. Dark stat = fuse / door / transformer first.

  • L1 / N120V to the IFCLine
  • XFMR24V to R24V
  • FUSEOn the IFC24V

24V safety chain

Door, limit, rollout in series. Open anywhere kills heat.

  • DOORInterlock24V
  • LIMITMain limit — rise / no airflow24V
  • ROLLOUTManual reset. Do not jumper and leave24V

Inducer + one pressure switch

W → inducer 120V → PS closes → IFC continues. One hose, one switch.

  • IND120V from the IFC to the inducerLine
  • PS24V prove back to the IFC24V
  • HOSESingle hose. Do not add a second because two-stage boards have two.24V

HSI + single valve

Igniter is 120V from the IFC. Valve is 24V. Flame rod is µA DC back to the IFC.

  • HSI120V hot-surface igniter — not 24VLine
  • VALVE24V to the single solenoid24V
  • FLAMEµA DC on the rod. Not a 24V circuit24V

PSC blower + run cap

Heat / cool / park taps on the motor. The cap is on this blower — not the outdoor dual can.

  • HEATHeat speed tap24V
  • COOLCool speed tap24V
  • PARKUnused leads parked24V
  • CAPRun capacitor on the blowerCap

Landing

  • LineL1IFCinducer

    120 VAC after W

  • 24VIFCPSIFC

    ~24 VAC prove. Open PS = no ignition.

  • LineIFCHSI

    120 VAC during trial

  • 24VIFCgas valve

    ~24 VAC after flame prove starts

  • 24VFlame rodIFC

    µA DC. Not 24V.

  • LineIFCblower

    120V tap + cap

Prove it

  • 24 VAC from R to C at the IFC. Fuse / transformer first if the stat is dark.
  • W at the IFC under a heat call. Then inducer / igniter / valve per THIS door card.

Do not

  • Do not land a ComfortBridge 1/2 or Infinity ABCD pair on this IFC.
  • Do not hunt W2 / E8 / high-fire on a one-stage door.
  • TWIN must be empty on a standalone.

9-speed tap, PSC, and CT motors share this thermostat landing. The motor is on the IFC harness diagram.

Sequence

  1. 1

    W

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

Faults on this IFC

Step 1, then 2, then 3. Expected reading and the fail branch sit under each check.

3 flash

PS open

lockout

Draft. 92% trap / PVC / inducer.

  1. 1 Prove inducer and the live code

    Do not pull power — that clears the Goodman GMSS92 active code. Write 3 flash. Is the inducer spinning on this call? Silent inducer is not a pressure switch. Trap and collector first. 92% still makes condensate.

    Expect: 120 VAC at the inducer on a heat call. Wheel turning.

    If fail: 120 VAC missing → IFC / door switch / incoming power. Voltage + dead motor → inducer.

    If pass: Inducer running + this code → trap, hose, switch, vent (step 2).

  2. 2 Trap, collector, and the hose

    A drowned 96% trap will not make collector pressure. Pull the trap, flush it, confirm the collector box and inducer outlet are not full. Hose cracked, off the port, or full of water fakes an open switch. Inducer 120 VAC, hose on the only tap, PVC termination.

    Expect: Trap flowing, hose dry and downhill, ports not swapped on a two-switch board.

  3. 3 Switch ohms, then vent load

    Ohm the pressure switch: NO, must close when that inducer speed is making the collector setpoint. If the switch is good, walk the PVC — bird screen, ice, long 2" run, wind, shared chase.

    Expect: Single PS: NO. Closed only with inducer up.

    If fail: Replace the open switch only after the vent and trap are proven.

    If pass: Switch closes on draft and the code stays → IFC input.

4 flash

Limit

warn

Airflow.

  1. 1 Airflow before you touch the limit

    On Goodman GMSS92 a limit is airflow or overfire until proven otherwise. Do not replace the limit first. Filter, blower wheel, A-coil, and the heat-speed setting for THIS motor (tap, model plug, or communicating CFM — not a sister SKU chart). Filter, speed tap, coil.

    Expect: Rise in the rating-plate window. Static vs this cabinet’s blower chart.

  2. 2 Measure static and temperature rise

    Total external static vs the Goodman GMSS92 blower chart for this cabinet size. Supply minus return rise after 8–10 minutes. A new 5" media cabinet or closed supplies will trip this all winter.

    Expect: Rise typically 35–65 °F — rating plate wins.

    If fail: Fix the restriction or the heat-speed setting. The limit is doing its job.

    If pass: Airflow in range → step 3 (overfire / limit itself).

  3. 3 Overfire, then the limit circuit

    Clock the meter / manifold on the stage that is tripping vs the rating plate. Then ohm the limit after it cools — a limit that never recloses is failed. Rollout in the same circuit is a different call (see rollout on this door card).

    Expect: Manifold on plate. Limit closed when cool.

7 / 8 flash

Flame / igniter

warn

Rod or HSI.

  1. 1 Ohms at the igniter, then at the IFC

    On Goodman GMSS92 measure cold ohms at the igniter plug, then at the IFC connector. An open at the plug is the element or local harness. Open only at the IFC is the harness rub-through on the collector. µA, nitride ohms, 120 VAC during trial.

    Expect: Nitride cold ohms per THIS door sticker — do not use an 80% Norton chart.

  2. 2 120 VAC during warm-up

    Call for heat and measure 120 VAC at the igniter during the warm-up window. 0 V + good ohms = IFC igniter relay. Voltage + no glow = cracked nitride.

    Expect: 120 VAC only during warm-up. Visible glow before the valve opens.

  3. 3 Do not keep cycling a cracked element

    A cracked nitride can ohm ‘good’ cold and open hot. If ohms and voltage are good and there is no glow, replace the igniter. Confirm polarity/ground (this plate’s polarity code) before you condemn a new igniter.

    Expect: One clean light after a known-good igniter and a proven ground.

Workflows

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

Before you cut the wrong vent.

  1. 1 Prove the call and the live code

    Plate GMSS92 = 92% condensing. Trap/PVC. Stay here.

    Expect: Write whatever Single-stage LED IFC (92%) is showing. Active code repeats until power is pulled.

    If fail: No call at the IFC → stat / harness. Do not change gas parts.

  2. 2 Isolate the first failed step in the sequence

    Plate GMSS96 = same flashes, 96% secondary. Use that chart if you need the 96% trap notes.

    Expect: The first dead output or open prove.

  3. 3 Confirm with a number, then the next part

    Plate GMS80 / GMES80 = metal vent. 3-flash is a chimney. Wrong page.

    Expect: Single PS: NO. Closed only with inducer up.

    If fail: Stay on this plate. The out-of-range reading is the part.

    If pass: Reading in range → the next step in this workflow is the repair.

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.

Related plates

Install this plate

Install GMSS92 as a 92% condensing flash furnace. Still PVC and a trap — not an 80% chimney.

Cat IV 92% · PVC collector · single-stage · one PS · LED 1–9 (same meanings as GMSS96)

Vent

  • 92% still condenses. Prime the trap. 3-flash is collector / PVC / inducer.
  • Secondary and vent load differ from GMSS96 — do not steal a 96% vent table blindly; use the GMSS92 I/O lengths.

IFC

  • Same 1–9 flash language as GMSS96. Rapid flash = polarity.
  • Not GR9S96 (7-seg EE). Not GMS80 (metal vent).

First fire

  1. 1W call through PS prove. Drain the 92% trap before you change an inducer.
  2. 2Rise vs the GMSS92 tap chart.

Do not on Goodman GMSS92

  • Do not treat 3-flash as a chimney / liner problem. There is no Category I vent on this plate.

Maker literature

FieldBench does not host manufacturer files. Each link opens the maker’s own literature page in a new tab.

Warranty and bulletins

Affected models, serial range, symptom, remedy, date. Maker files open on the manufacturer site.

All bulletins

  • Dated GM* certificate

    warranty sheet

    Older Goodman GM* furnace limited warranty

    GM* generation furnace warranty terms · Dated certificate for that generation

    Open factsOpen manufacturer PDF

  • Dealer portals

    dealer

    Where remaining service letters live

    Current-year service letters not on a public literature page · Maker dealer portal

    Open factsOpen manufacturer PDF