Goodman GMEC960803BN Error Code Green LED Solid On: Standby
What Does Code Green LED Solid On Mean?
On the Goodman GMEC960803BN, a solid (non-flashing) green LED is the Integrated Control Module's standby indication. The board has 115V and 24V power, has passed its internal checks, and is simply idle, waiting for the thermostat to ask for heat, cooling, or fan.
The board uses a tri-color scheme where green means a normal state, amber means a normal heating call, and red means a fault. Solid green is the baseline "everything is fine, nothing is running" state. You will see it any time the house is at temperature and no thermostat call is active.
If your home is not warming up yet the board still shows solid green standby, the furnace is not receiving a heat call. That points to the thermostat or its wiring rather than the furnace itself — check that the thermostat is set to Heat, the setpoint is above room temperature, and the system is not switched off.
What You'll Notice
- A steady, non-flashing green light on the control board while the furnace is idle
- No blower, inducer, or burner activity because no thermostat call is present
How This Is Diagnosed
No diagnosis is needed for a healthy standby light. If the furnace should be running but stays in solid-green standby, the check moves to the thermostat: confirm it is set to Heat with the setpoint above room temperature, and that its batteries or power are good. If the thermostat is clearly calling but the board never leaves standby, the thermostat-to-furnace wiring is inspected for an open or loose connection.
- The furnace stays in solid-green standby and never starts even though the thermostat is set to Heat and calling — the thermostat wiring may have an open or loose connection
Frequently Asked Questions
Is a solid green light on my furnace bad?
No. Solid green is the normal standby indication on the GMEC960803BN. It simply means the board is powered and waiting for the thermostat to call.
The light is green but the furnace won't heat — why?
If the board sits in green standby while you expect heat, it is not receiving a call. Check that the thermostat is in Heat mode with the setpoint raised; if it is and nothing happens, the thermostat wiring may need inspection.
✓ Verified against manufacturer service manual — March 2026