Goodman Furnace E2 Error Code - Low Flame Signal Fault

What Caused This Error?

The control system reports E2 when the monitored condition described by the error code is outside the expected operating range. In this case, the most likely trigger is carbon buildup on flame sensor rod. Other common contributors include poor furnace electrical earth ground connection and misaligned flame sensor outside of flame path.

Step-by-Step Diagnostic Check

1. Shut off power, remove flame sensor, and clean steel probe with fine Scotch-Brite pad.
2. Check ground wire screw on furnace cabinet for tightness and paint insulation.
3. Ensure burner flame completely engulfs tip of flame sensor.
4. Replace flame sensor.