Goodman Furnace 6 (red LED) error code
The burner temperature switch opened, indicating excessive heat in the burner area — from an oversized flame, a blocked flue or air inlet, or a failing inducer fan.
Also shown as: 6 red flashes, six red flashes, fault code 6 red, burner temperature switch open
Last updated: September 30, 2026
What causes the 6 (red LED) error?
- Flame too large or lifting off the burner
- Blocked flue or combustion-air inlet
- Failing inducer motor reducing draft
How to fix Goodman 6 (red LED) — step by step
Work through these in order, from simplest and safest first. Stop as soon as the code clears.
- Check outside vent terminations
Clear any debris, snow, or nests from the intake and exhaust pipes outside the home. - Replace the air filter
Restricted airflow can contribute to abnormal combustion. Install a clean filter. - Call a technician
Burner and flue problems must be diagnosed with combustion testing equipment — this is not a homeowner repair.Safety warning: Do not open the sealed burner compartment. The ultra-low-NOx burner box is factory-sealed for safety.
When to call a technician
- The code appears at all
- You see soot, scorching, or smell unusual odors near the furnace
Frequently asked questions
What is the burner temperature switch?
A safety switch that trips when the burner compartment gets hotter than designed — it shuts the furnace down before damage or unsafe combustion can continue.
Can I reset the switch myself?
No. It must be inspected by a technician to find why it tripped before the furnace runs again.
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.