Goodman Furnace 9 Flashes: High-Stage Pressure Switch Open

Last updated Sep 16, 2026 · By fixme.vip Editorial

Goodman furnace 9 flashes: what it means

Nine flashes on a two-stage Goodman (or Amana) furnace control board means the high-stage pressure switch failed to close on high fire. When the furnace calls for high heat, the board runs the inducer at high speed and expects the high-stage pressure switch to sense adequate draft and close its contacts. If that switch does not close within the allowed time, the board reports 9 flashes.

This is a safety interlock working correctly: the board is confirming the venting can handle high-fire combustion before it opens the gas valve to high stage. On most models, the furnace either stays on low fire (weaker heat) or retries before dropping back. It is not a gas leak and not an immediate hazard, but it does need a pro because the fixes live inside the cabinet.

One important caveat: the meaning of a 9-flash count varies by control board. On the two-stage integrated controls listed above it points to the high-stage pressure switch, but Goodman and Amana have used different flash-code legends across board generations and product families. Read the diagnostic chart printed on the inside of your blower-compartment door — that legend is the authoritative reference for your specific furnace — before acting on this code.

Goodman furnace 9 flashes: common causes, ranked by probability

1. Blocked or restricted vent/intake on high fire — snow, ice, nests, or debris in the flue or intake pipe that only chokes airflow enough to matter at high speed.
2. Condensate blockage in the inducer or drain — a clogged condensate trap or drain line lets water back up and prevent the high-stage switch from closing.
3. Cracked, loose, or pinched pressure-switch tubing — the hose to the high-stage switch is off, split, or has water sitting in it.
4. Weak or failing inducer motor — the inducer spins but no longer moves enough air to create the pressure the high-stage switch needs.
5. Failed high-stage pressure switch — the switch itself is out of calibration or has failed open.
6. Wiring/connector faults — a loose or corroded connection between the switch and the control board.
7. Blocked heat exchanger or secondary passages — sooting or debris raising resistance so draft can’t reach high-fire spec.

Standard troubleshooting practice is to verify venting and the switch/tubing before condemning the inducer or the board.

How to fix Goodman furnace 9 flashes: safe checks first

These are the only steps a homeowner should do:

• Air filter: A clogged filter chokes airflow. Replace it if it’s dirty and see if the code clears.
• Thermostat: Confirm it’s set to Heat and calling. If it has batteries, replace weak ones.
• Breaker / furnace switch: Cycle the furnace breaker or the switch on the unit once. That gives the board one clean retry — once only, not repeatedly.
• Outdoor vent and intake pipes: From outside and at ground level, look for snow, ice, leaves, or a nest blocking the PVC termination. Clear only what you can safely reach.
• Condensate drain: If you see standing water or an overflowing trap on a high-efficiency unit, that’s a clue — but only clear a visibly accessible external drain line.
• Registers and vents: Make sure supply and return grilles aren’t blocked by furniture or rugs.

If the code returns after these, stop — the remaining work is inside the cabinet.

How a technician will diagnose it

A tech will typically:

• Read the stored fault and confirm the board legend shows high-stage pressure switch open.
• Inspect the flue and intake for restriction, then check the concentric or two-pipe termination.
• Check the high-stage pressure switch tubing for water, cracks, or a disconnected hose.
• Use a manometer to measure inducer pressure at high fire and compare it to the switch’s set point, which is normally stamped on the switch body and listed in the service and parts literature.
• Verify the switch contacts close at spec with a multimeter; a switch that never closes at correct pressure gets replaced.
• Inspect the inducer motor for slow speed, bearing wear, or a debris-loaded wheel.
• Check the condensate trap and drain for blockage causing back-pressure.
• Inspect wiring, connectors, and the control board as a last step.

Ask the tech what draft pressure they actually measured versus the switch’s stamped set point — that tells you whether it’s a venting, inducer, or switch problem.

Symptom, cause and what to do

Goodman furnace 9 flashes repair cost

Honest US ballpark ranges (parts + labor):

• DIY filter / thermostat batteries / clearing outside vent: $0–$40
• Condensate trap or drain cleaning: $100–$250
• Pressure-switch tubing replacement / reseating: $120–$220
• High-stage pressure switch replacement: $150–$350
• Inducer motor/assembly replacement (two-stage or ECM): $400–$1,200
• Control board replacement (two-stage integrated board): $400–$1,200
• Diagnostic/service call: $100–$225, higher after hours (often credited toward the repair)

Costs vary by region, model, and access. A venting or tubing fix is cheap; a two-stage inducer assembly or integrated control board is the expensive end, and either one can push the job toward the top of the range above.

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