AR9S80

This board

Self-diagnostic IFC · single 7-segment · wiring 0140F20001-B

• door card is wiring 0140F20001-B. Read left to right. Do not kill power — that clears the active code.
• Codes are E0–E7, EA, Eb, Ec, Ed, En, plus TWIN, LE1, EEH, and A2L pair tokens. One pressure switch only — E1 stuck closed, E2 open.
• E2 is Category I draft: chimney, B-vent, 4" metal, inducer, common-vent. It is not a 96% trap / PVC / collector story.
• A2L pair codes only apply when this furnace is tied to an R-32 / A2L outdoor. Ignore them on R-410A pairs.

Sequence

1. W. IFC proves limits/rollout closed, starts the single-speed inducer.
2. Prove PS. The only pressure switch must close against the metal vent. Already closed with inducer off → E1. Never closes → E2 (chimney / B-vent / 4" / inducer).
3. HSI / valve. Hot-surface igniter warm-up, then the single solenoid. Open igniter → En / E7. Failures stack toward E0.
4. Blower. Heat-on delay, then the 9-speed ECM on the selected heat tap (factory F02). F01 is not recommended for heating.
5. Satisfied. Valve off, inducer post-purge, blower heat-off delay. Unexpected flame → E4.

Faults on this IFC

• E0

  Retry / recycle lockout

  lockout

  Too many failed ignition attempts or flame losses on this call.

  • Watch one full try: inducer, HSI glow, valve click, flame, µA.
  • Gas supply and manifold vs this 80% plate.
  • Ground and flame-rod cleanliness.
  • Do not keep resetting — find which step dies.
• E1

  PS stuck closed

  lockout

  The only pressure switch is made with the inducer off.

  • Unplug the only PS. Code change = welded switch or residual draft in the hose.
  • Hose holding chimney draft with inducer off — wind on a tall stack can fake E1.
  • IFC input shorted — only after the switch ohms open.
• E2

  PS open — metal-vent draft

  lockout

  Inducer is on and the only switch will not close. This is a chimney / B-vent / 4" metal / inducer call — not a drowned 96% trap.

  • Inducer 120 VAC and spinning. A dead inducer is E2 with a perfect switch.
  • Chimney, B-vent, common vent, cap, liner, and 4" connector. Single-wall connector needs 6" to combustibles.
  • Cold chimney that will not establish draft on a first morning call. Spillage at the draft hood / collector.
  • Hose on the only tap, dry, not pinched. Do not start looking for a PVC trap — there is none.
• E3

  Open high limit

  warn

  Primary limit opened. Airflow or overfire.

  • Heat tap first. Factory default F02. F01 is not recommended for heating.
  • Filter, wheel, coil sitting on an 80%. A new media cabinet will trip E3 all winter.
  • TES vs the AR9S80 blower chart for this cabinet. Rise ranges are 20–50 up to 40–70 on 1205D.
  • Clock the meter — overfire trips limits with a clean filter.
• E4

  Flame when valve should be off

  hazard

  Rod sees flame with the solenoid de-energized.

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

  Open fuse

  warn

  24 V fuse on the IFC is open.

  • Short on W, Y, G, humidifier, EAC.
  • Unplug the tstat harness and replace the fuse.
• E6

  Low flame signal

  warn

  Flame present, µA below threshold.

  • Clean rod with a non-scratch pad.
  • Chassis ground, manifold, LP conversion (this plate uses LPM-31 with an LP switch — not LPM-33).
• E7

  Igniter relay fault

  lockout

  IFC did not see the igniter circuit behave as commanded.

  • Hot-surface igniter ohms cold per this sticker — not an AR9S96 nitride chart.
  • 120 VAC during warm-up. Cracked element.
• EA

  Line polarity / ground

  lockout

  L1/N reversed or chassis ground missing.

  • Hot and neutral at the IFC. Burner-box ground screw.
• Eb / Ec

  Gas valve circuit

  lockout

  Internal (Eb) or external (Ec) gas-valve electrical fault.

  • Valve coil ohms, 24 VAC at the harness during trial.
• Ed

  Open rollout

  hazard

  Manual-reset rollout. Treat as flame outside the exchanger until proven otherwise.

  • Primary exchanger, burner alignment, crossover, blocked flue / chimney.
  • Reset only after the cause is fixed.
• En

  Igniter open

  lockout

  Igniter circuit measures open.

  • Ohms at the igniter plug, then at the IFC.
  • Harness rub-through.
• EEH

  Grounding error

  lockout

  IFC failed its ground check (sister to EA).

  • Green ground to cabinet and IFC. Painted screw, missing star washer.
• TWIN

  Twin error

  lockout

  Twinning miswire or twin terminal active on a standalone unit. Door card lists TWIN on 0140F20001-B.

  • If not twinned, nothing should be on the TWIN terminal.
  • Twinned pair must be same family / same IFC revision.
• LE1

  Low circulator current

  lockout

  9-speed ECM current too low.

  • Harness seated at motor and IFC. A half-seated tap plug throws this.
  • Locked rotor, wet winding, or a PSC motor someone hung on this IFC.
• FE3 / LE4 / SE5 / rE6

  A2L mitigation

  hazard

  Leak / comm / relay alarm from the A2L board when paired with an R-32 / A2L outdoor.

  • Only valid on A2L pairs. On 410A this is a miswired mitigation harness.

Workflows

Test points

Pressure switch

One NO switch. Closed only with inducer up against the metal vent. Not a 96% collector tap.

Manifold

Single-stage plate value. Reduce input 4% per 1000' above 4500'.

Flame rod

µA per this door card. Rising while running is the goal.

HSI

Hot-surface igniter per SS — not the AR9S96 nitride sticker. 120 VAC during warm-up.

ECM taps

Heat default F02. Cool default F04. Two-stage outdoor: 0805C Y2=F08 / Y1=F02; 1205D Y2=F06 / Y1=F05.

Vent

4" Category I metal. Single-wall connector 6" to combustibles. B-vent 1".

Gotchas

• Techs treat every Amana 9-speed E2 as a 96% trap. On this plate that wastes the call — there is no collector to drown.
• Do not cut PVC onto an AR9S80. Category I metal only.
• LPM-31 (with LP switch) is the only LP kit on this SS. LPM-33 is AR9S96. LPM-34 is AR9T96 / ARVT96.
• HANG20 is the high-altitude kit, not HASFK. Grabbing the 96% HASFK carton is a parts-runner miss.
• Downflow sub-base is SBT, not CFSB. CFSB17/21/24 are the condensing downflow bases.
• Looks like AR9S96 in the basement until you look at the flue. 4" metal = this page. PVC = the other page.
• GMS80 / GMES80 flash 1–9 is a different 80% card. Do not count flashes on this 7-seg.

Related plates

• amana-ar9s96 — 96% single-stage 9-speed sister — Cat IV PVC, LPM-33, E2 is a trap. Wrong vent story for this cabinet.
• amana-ar9t96 — Two-stage 96% 9-speed — dual PS, E8/E9, PVC. Not this 80%.
• goodman-gms80 — Goodman 80% flash cousin. Same metal-vent physics, LED 1–9 instead of this 7-seg.
• amana-am9s96 — Older Amana 96% flash. Condensing — not this chimney.