Goodman Error Code E4 indicates Flame sensed with no call for heat (Improper flame). Start by checking the most common and safe items identified in the troubleshooting section. If the code returns after those checks, professional diagnosis is recommended.
Easy
Flame sensed with no call for heat (Improper flame)
Induced draft and circulator blowers run continuously; no furnace operation; LED displays E4; thermostat shows ‘Check Furnace’
Short to ground in flame‑sense circuit; lingering burner flame; slow closing gas valve
Correct short at flame sensor or wiring; check for lingering flame; verify proper operation of gas valve; turn power off before repair
Flame sensor, flame‑sensor wiring, gas valve
Call an HVAC technician if the error persists after completing the recommended basic troubleshooting steps or if the system repeatedly locks out.
Disconnect power before inspecting the equipment. Never bypass safety devices or operate the system if you suspect unsafe conditions.
Learn more about the furnace components and operating conditions commonly associated with diagnostic error codes: