Goodman Furnace 1 (amber LED) error code
The amber LED's single flash means the flame-sensing signal is weak. The furnace may still run, but a weak flame signal often leads to nuisance shutdowns or a lockout.
Also shown as: 1 amber flash, one amber flash, amber LED flashing once, fault code 1 amber, low flame signal
Last updated: September 30, 2026
What causes the 1 (amber LED) error?
- Dirty or oxidized flame sensor rod
- Flame sensor positioned poorly in the flame
- Weak burner flame
- Poor ground connection
How to fix Goodman 1 (amber LED) — step by step
Work through these in order, from simplest and safest first. Stop as soon as the code clears.
- Check the simple things first
Confirm the gas valve is fully open, the thermostat is calling for heat, and the air filter is clean. - Have the flame sensor serviced
A technician can clean the sensor rod, check its position in the flame, and measure the flame signal in microamps.Safety warning: The flame sensor sits inside the burner compartment. Cleaning or adjusting it is a job for a qualified technician — do not reach into the burner area.
When to call a technician
- The furnace shuts off and restarts repeatedly
- The amber flash appears alongside heating that never completes
Frequently asked questions
What is a flame sensor?
A small metal rod that sits in the burner flame and tells the control board a flame is actually present. If its signal is weak, the board cannot be sure the burners lit.
Can a weak flame signal fix itself?
Rarely — oxidation and positioning problems get worse over time, not better. A quick professional cleaning usually resolves it.
Sources
Every meaning and fix above was checked against official manufacturer documentation:
FixCode provides general troubleshooting information only — not professional repair advice. If you are unsure about any step, stop and call a qualified technician. Repairs done incorrectly can be dangerous and may void your warranty.