Goodman Furnace 1 (red LED) error code
The furnace's control board tried to light the burners three times and failed each attempt, then shut the furnace down into a safety lockout. No heat will run until the problem is fixed and the lockout is cleared.
Also shown as: 1 red flash, one red flash, red LED flashing once, fault code 1 red, ignition failure lockout
Last updated: September 30, 2026
What causes the 1 (red LED) error?
- Gas shutoff valve near the furnace is closed
- Worn, cracked, or disconnected hot-surface igniter
- Dirty, corroded, or mispositioned flame sensor
- Weak or missing ground connection to the control board
How to fix Goodman 1 (red LED) — step by step
Work through these in order, from simplest and safest first. Stop as soon as the code clears.
- Confirm gas is on
Make sure the manual gas shutoff valve in the gas line near the furnace is fully open (handle parallel to the pipe). If other gas appliances in the home also have no gas, contact your gas utility. - Check thermostat and filter
Set the thermostat to Heat with a setpoint several degrees above room temperature, and replace a dirty air filter so airflow is normal before the next attempt. - Have a technician test the ignition parts
A licensed HVAC technician should test the igniter, flame sensor, and gas valve, and verify grounding and gas pressure.Safety warning: Do not open the burner compartment or handle the igniter yourself — the igniter is fragile, and gas components must only be serviced by a qualified technician.
When to call a technician
- The lockout returns after the gas valve is confirmed open
- You smell gas — leave the area and call your gas utility immediately
- The furnace is more than a few years old and has never had the ignition system serviced
Frequently asked questions
Can I clear the lockout myself?
Cycling power at the furnace service switch clears it once. If the furnace locks out again on the next call for heat, it needs professional diagnosis — repeated resets can damage the igniter.
Is a 1-flash lockout dangerous?
The lockout itself is a safety feature. The underlying cause (no gas flow, failing igniter, or weak flame sensing) should be diagnosed promptly, and any gas smell must be treated as an emergency.
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.