Goodman, Amana GMSS9 / GCSS9 error code 2 flashes
Pressure switch circuit closed
Goodman is the platform name, and your unit may not say it
Amana AMSS9 / ACSS9 is the same board with a different badge, so this page covers all of them. The fault, the checks and the parts are identical, which is why there is one page rather than one per brand.
Which models this applies to. Applies to every legacy flash furnace in this group: GMV8 / GMV9, GCH / GDH / GME / GMH, GDS / GHS / GMS / GKS, and GMN / GMP / GMT. The pressure switch is the proving switch on the draft hood, so the reading is the same on a GMN as it is on a GMV9.
Quick answer
On Goodman GMSS9 / GCSS9 (2000s), 2 flashes is a fault. It means pressure switch circuit closed. A first thing to check: Pressure switch stuck in the closed position.
- Applies to
- Goodman GMSS9 / GCSS9
- Goodman and Amana GMSS9, GCSS9, AMSS9, ACSS9 flash codes · Furnace · 2000s
- Type of code
- Fault
- Urgency: Needs attention soon
- First safe check
- Find the round pressure switch, usually clipped near the burner compartment or on the blower deck, and follow the clear plastic tube attached to it.
What 2 flashes means on this model
Before the burner was called for, the pressure switch reported that the furnace was already venting. Either the switch is stuck, or the clear tube running to it is holding air when it should be open to the draft.
Symptoms you will notice
- Furnace will not fire
- Short draft blower noise, then a click, then nothing
- No heat
- Code returns immediately after a reset
Common causes
The code tells you what the control detected, not which part failed. These are the causes we see most often, roughly in order of likelihood:
- Pressure switch stuck in the closed position
- Cracked, pinched or disconnected plastic pressure tube
- Water or condensation sitting in a low point of that tube
- Inducer motor spinning too slowly to move enough air to trip the switch
- Loose connector in the pressure switch circuit
What you can safely check
These are homeowner-level checks. None of them need you to open a live electrical compartment or work on gas.
- Find the round pressure switch, usually clipped near the burner compartment or on the blower deck, and follow the clear plastic tube attached to it.
- Inspect the whole length of tube for a crack, a kink, or water pooled in a dip.
- Watch the squirrel cage on the draft inducer while the furnace calls for heat. It should spin up quickly and evenly.
Do not do these
- ×Do not tape over, plug, or block the pressure switch. It is the part that stops the furnace releasing gas into a flue that is not moving air.
- ×Do not run the furnace with the burner compartment open.
When to call a technician
Book a technician, do not keep resetting it
This fault will not clear on its own. Every power cycle gives the control one more failed attempt, and repeated attempts are what turn a cheap part replacement into a seized or contaminated system.
- This is a fuel-burning appliance, so treat anything involving a burner, gas valve or flue as technician work. If you smell gas at any point, leave the property and call the gas utility from outside rather than continuing to diagnose.
- If the appliance has stopped mid-cycle, is making a noise you have not heard before, or smells burnt, stop reading here and call. Those are symptoms of something the fault code does not describe well enough.
Replacing a cracked tube and cleaning a blocked condensate drain are fine homeowner work. Replacing the switch is at the edge of it.
What it costs to fix
Parts
Pressure switch $30 to $90. Pressure tube $5 to $20. Inducer capacitor $15 to $40.
Labor
Usually under an hour. Straightforward once the burner compartment is open.
DIY or technician
Replacing a cracked tube and cleaning a blocked condensate drain are fine homeowner work. Replacing the switch is at the edge of it.
Typical US part and labor ranges, 2026. They vary by region, model and contractor, so treat them as a planning figure, not a quote.
Scope of this code
- Code table
- Goodman and Amana GMSS9, GCSS9, AMSS9, ACSS9 flash codes
- Models in scope
- Goodman GMSS9 / GCSS9, 2000s
- Checked
- Confirm on your own unit
- Find the model number on the data plate, then check this code in the service manual for that model. Manufacturers revise code tables between model years, and a revised board can renumber a fault.