FieldBench

Goodman

GMEC96

Furnace · Two-stage · constant-torque ECM · 96% AFUE

Two-stage 96% with a multi-speed / constant-torque ECM (X-13 style profiles). Conventional 24V. Dual pressure switches. Often a 7-seg that still speaks E0–E9 (low/high PS) like GR9T96 — but the motor is CT profiles, not a 9-speed tap card and not a ComfortBridge 14-pin serial.

Not GR9T96 (9-speed tap ECM — different motor plug and tap card). Not GMVC96 (communicating VS, triple 7-seg, 14-pin serial, ComfortBridge b0–b9/d0). Not GMSS96 (single-stage, one PS, LED flash).

Walk this in Diagnose

This plate

Input / AFUE
Up to 96% · two-stage heat
Staging
Two-stage valve · two-speed inducer · dual pressure switches
Blower
Constant-torque / X-13 style ECM — heat/cool/fan profile taps, not 9-speed and not serial VS
Control
Conventional 24V IFC · 7-seg E0–E9 (no ComfortBridge menu)
Tstat
Conventional 24V · W1 W2 Y G R C
Sister SKU
GCEC96 downflow / sister cabinet

This board

Two-stage 7-segment IFC · E0–E9 dual-PS language

  • E1/E2 = LOW-FIRE pressure switch. E8/E9 = HIGH-FIRE pressure switch. Same meanings as GR9T96.
  • There is no ComfortBridge menu, no idle/Ht1/CF status word, and no b0–b9 / d0 motor-card language. If you see those, you are on a GMVC96.
  • Airflow is a CT heat tap / profile, not a 9-speed tap card and not an IFC CFM menu.
  • Do not kill power before you write the 7-seg.

Sequence

  1. W1. IFC proves limits closed, inducer on low. Low-fire PS must close (E1 if already closed, E2 if it never closes).
  2. Trial. HSI then low-fire solenoid. Failures accumulate to E0. Igniter faults → E7.
  3. Blower. Heat-on delay, then CT motor on the selected heat profile. Wrong heat tap is the E3 generator.
  4. W2 / high fire. Inducer high. High-fire PS must close (E9 if open, E8 if already closed). Second solenoid opens.
  5. Satisfied. Valve off, post-purge, heat-off delay. Unexpected flame → E4.

Faults on this IFC

  • E0

    Retry / recycle lockout

    lockout

    Ignition or flame-loss retries exceeded on this call.

    • Watch one full try: inducer, HSI, valve, flame, µA.
    • Gas supply and manifold low then high.
    • Do not keep resetting.
  • E1

    Low-fire PS stuck closed

    lockout

    Low-stage pressure switch is made with the inducer off. Same meaning as GR9T96 E1.

    • Unplug the LPS. Code change = switch or water in the hose.
    • IFC input shorted only after the switch ohms open.
  • E2

    Low-fire PS open

    lockout

    Inducer on low, low-fire switch will not close. Same meaning as GR9T96 E2.

    • Inducer 120 VAC and spinning.
    • Trap, collector, PVC, LPS hose on the low tap — not teed to high.
  • E3

    Open high limit

    warn

    Primary limit opened. On this cabinet the usual cause is the wrong CT heat tap, not a failed limit.

    • Which heat profile is landed? CT motors have discrete 24V taps — a cool tap left on heat will trip E3.
    • Filter, wheel, coil, TES vs the GMEC96 blower chart.
    • Manifold low/high vs plate. Limit ohms after it cools.
  • E4

    Flame when valve should be off

    hazard

    Rod sees flame with both solenoids de-energized.

    • Shut the gas cock. Leaking valve — replace, do not jump.
    • Rod shorted to ground or IFC flame circuit.
  • E5

    Open fuse

    warn

    IFC automotive fuse is open.

    • 24 V short on W, Y, G, humidifier, EAC.
    • Unplug tstat harness and replace fuse.
  • E6

    Low flame signal

    warn

    Flame present, µA below threshold.

    • Clean rod, chassis ground, manifold / LP conversion.
  • E7

    Igniter fault

    lockout

    Igniter circuit did not behave as commanded.

    • Igniter ohms cold, 120 VAC during warm-up, cracked nitride.
    • Harness rub-through on the collector.
  • E8

    High-fire PS stuck closed

    lockout

    High-stage switch is made with the inducer not on high. Same meaning as GR9T96 E8.

    • Second switch — do not confuse with E1.
    • Welded HPS, water in the hose, W2 shorted to W1.
  • E9

    High-fire PS open

    lockout

    Inducer on high, high-fire switch never closes. Runs on low, will not go high. Same meaning as GR9T96 E9.

    • Inducer actually changes speed on W2?
    • HPS hose on the high tap only.
    • Vent capacity / condensate only under high fire.
  • EA

    Line polarity / ground

    lockout

    L1/N reversed or chassis ground missing.

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

Workflows

Identify GMEC vs GR9T96 vs GMVC96

First minute. Plate dirty or mixed parts in the cabinet.

  1. CT / X-13 style profile plug (typically 24V heat/cool/fan taps at the motor) + two-stage + 7-seg E0–E9 = GMEC96. Stay here.
  2. 9-speed tap harness / tap card on the motor, single 7-seg, no CT common = GR9T96.
  3. 14-pin serial motor + triple 7-seg + menu buttons = GMVC96. ComfortBridge. Leave this page.
  4. One PS and a flashing LED = GMSS96.
  5. A ComfortBridge serial motor or a 9-speed motor in this cabinet will not run on CT profiles. Match the motor family before you chase E-codes.

No high fire (E9)

Runs on low, long run times, E9.

  1. Confirm W2 at the IFC (or the staging timer). No W2 → stat / wire, not a switch.
  2. Listen for inducer speed-up. No speed-up → IFC / inducer. Speed-up + E9 → high-fire PS path.
  3. HPS hose on the high tap only. A tee with the LPS is a first-install miss on this collector too.
  4. Manifold high-fire vs plate. A valve that never opens stage 2 looks like an airflow complaint.
  5. This is not a ComfortBridge CFM menu and not a 9-speed tap — do not ‘fix high fire’ by moving a blower tap.

Limit from the wrong CT heat tap

E3, blower on, burners drop. Common after a motor swap or a ‘set it on 3’ service call.

  1. Read the heat tap / profile at the CT motor. Cool or low-fan landed on heat is the usual E3.
  2. Set heat to the GMEC96 rise range on the rating plate (typically 35–65°F), not a GR9T96 9-speed chart and not a GMVC96 CFM menu.
  3. Filter, coil, TES. A CT motor will not ramp out of a brick the way a VS motor tries to.
  4. Clock input / manifold before you replace the limit.

Test points

Motor plug
CT / X-13 profile taps. Not a 9-speed tap card. Not a 14-pin ComfortBridge serial.
LPS / HPS
Two NO switches, two hoses, two codes (E1/E2 vs E8/E9). Never teed.
Heat tap
CT heat profile vs rise on the plate. Wrong tap = E3.
Manifold low / high
Rating plate wins. Clock input if in doubt.

Gotchas

  • Same E1/E2/E8/E9 sticker language as GR9T96. The motor is the difference — parts-house ‘96% ECM’ is usually the wrong family.
  • Do not look for b0/b1/d0 on this IFC. Those are ComfortBridge GMVC96 codes.
  • GCEC96 is the sister cabinet. Codes do not change.

Related plates

  • goodman-gr9t96 — 9-speed tap cousin. Same dual-PS E-codes, different motor plug.
  • goodman-gmvc96 — ComfortBridge VS. 14-pin serial + triple 7-seg. Wrong motor family for this cabinet.
  • goodman-gmss96 — Single-stage flash. One PS. Not this two-stage CT board.