Goodman furnace 1 green flash: Normal operation — low stage cooling
One green flash means the furnace is running its blower for low stage cooling. The furnace itself is not heating — it is supplying air for the air conditioner or heat pump.
Applies to: Goodman GMEC96 and Amana AMEC96 two-stage gas furnaces with a three-colour diagnostic LED, running the indoor blower for a cooling call.
What it means
The furnace cabinet contains the indoor blower that the cooling system also depends on, so the furnace control runs during cooling even though no gas is burning. Green on this board means a cooling call: one flash for low stage cooling, two for high stage or a single-stage compressor. Someone who opens the panel in summer, sees a light flashing, and starts counting will find a code that does not appear on any fault list, because it is not a fault. The furnace is acting as the air handler. Worth knowing alongside it: on this board green never indicates a problem. Faults are red, and status is amber or green.
Most common causes
- The thermostat is calling for low stage cooling, with the compressor running on its lower capacity.
- A two-stage outdoor unit operating on first stage, which is normal in mild weather.
- The blower running on the cooling speed, which is the furnace's role during a cooling call.
How to diagnose it
- Confirm the flashes are green rather than red or amber.
- Note whether the house is cooling. If it is, nothing here needs attention.
- If the blower runs but no cool air arrives, the problem is in the cooling equipment or refrigerant circuit, not in this code.
- Two green flashes means high stage cooling, and is equally normal.
How to fix it
- Nothing. This is a normal operating indication.
- If cooling performance is the actual complaint, the furnace control is reporting that its part is working — look at the outdoor unit.
Notes
Because the furnace runs the blower for cooling, its diagnostic LED is showing something all summer. That is often the first time a homeowner notices the light at all, which is why a normal cooling indication gets mistaken for a fault stored over the winter.
Related
- 2 green flashes — Normal operation — high stage or single stage cooling
- 4 amber flashes — Cooling called with no fan call
All codes for this manufacturer
Goodman and Amana furnace fault codes — every code, with what differs between models.
Not sure this is your brand?
The same count means something else on other furnaces. What 1 flash means on every brand puts them side by side.
Models this code appears on
From the manufacturer's per-model database. If your model is not listed, this code may not exist on your board, or it may mean something different — check the model page.
What the fix costs
One green flash is the furnace lending its blower to low-stage cooling — normal, and free. When a cooling complaint arrives with this code showing, the display has already done the first hour of diagnosis: the call reached the furnace and the blower answered, so a warm house points outdoors — condenser, charge, compressor — while no air at the registers at all points at the blower side. That split decides the bill. Outdoor-unit work is quoted after a $75–150 diagnostic (repair cost guide); blower work spans the full $400–1,500+ range of the blower motor cost guide, where the motor type your particular furnace carries sets the number.
DIY or call a pro?
Stand at a register before doing anything else: air moving or not is the one observation that routes this whole page. Filters, registers, and confirming the outdoor unit is running are homeowner checks. Past that, both branches are professional — refrigerant is licensed work, and blower diagnosis means line voltage and, on PSC motors, a capacitor that holds its charge after the power is off. Give the dispatcher the code and the register observation together; 'one green flash, blower running, no cooling' is practically a work order.
What this looks like
From the outside, this usually shows up as the blower runs when it should not — that walkthrough covers what to check in order, and when it stops being a homeowner job.