Goodman Furnace Continuous flash: Reversed polarity or poor ground (continuous or rapid flash)
Updated October 2026 · Sourced from Goodman documentation
🛑 Turn it off and call a licensed pro
The LED flashes continuously or rapidly and the furnace will not operate. The manual lists reversed 115 or 24 volt polarity, swapped orange and gray transformer wires or a poor unit ground.
Is it safe to keep running? No. Turn it off and get it checked. Turn the furnace off at the breaker and call a licensed technician or electrician to correct the wiring and ground.
Continuous flash at a glance
| Code / how it shows | Meaning | Applies to |
|---|---|---|
| Continuous flash Diagnostic LED seen through the blower door window | Reversed polarity or poor ground (continuous or rapid flash) | Goodman GMS8 / Amana AMS8 / GDS8 / ADSS8 80% single-stage gas furnaces (older flash-code control) |
🛑 Stop and call a licensed pro if
- Turn the furnace off at the breaker and call a licensed technician or electrician to correct the wiring and ground.
- You smell gas. Leave the house, do not touch switches, and call your gas utility from outside.
- Flame rollout, limit or pressure switch codes that come back after one reset.
- Anything involving the control board, gas valve, flame sensor, igniter or venting.
- A carbon monoxide alarm sounds. Get everyone outside and call 911 or the fire department.
Safe first steps for any Goodman code
- Count the LED flashes through the blower door window before you switch anything off. Cutting power can clear the code.
- Replace or clean the furnace air filter.
- Check the thermostat: correct mode, set above room temperature, and fresh batteries.
- Make sure the furnace power switch and breaker are on. If the furnace has locked out, turning the power off and back on once restarts it.
- Make sure the gas valve is in the ON position, following the lighting instructions on the furnace label only.
- On high-efficiency furnaces, look at the outside vent and intake pipes for snow, ice, leaves or nests (look only, do not take pipes apart).
Source: Goodman GMS8/AMS8/GDS8/ADSS8 80% Single Stage Service Instructions RS6612006 (July 2013), pp.37-39. Codes are series-specific, so your unit's own manual is the final word. Reviewed October 2026.
Shaun Cain · Certified HVAC & Refrigeration Technician · Ask an HVAC technician
Related Goodman codes
1 flash : Ignition lockout (no flame)2 flashes : Pressure switch stuck closed3 flashes : Pressure switch stuck open4 flashes : Open primary or auxiliary limit5 flashes : Flame sensed with no call for heat6 flashes : Open rollout limit7 flashes : Low flame sense signal8 flashes : Igniter circuit fault or poor groundE0 : Lockout after three failed ignition attemptsE1 : Low-stage pressure switch closed at start of heatingE2 : Low-stage pressure switch circuit openE3 : Primary limit circuit open (furnace overheating)