What does Day & Night code 6 Flash mean?
Day & Night furnace code 6 Flash means the burners failed to ignite, or the flame signal was lost during operation on the supported control family. Confirm the model number and diagnostic chart inside the furnace door before replacing parts.
What causes Day & Night code 6 Flash?
- A dirty or weak flame sensor
- Unstable gas pressure or burner flame
- Poor grounding or flame-sensor wiring
Can I troubleshoot Day & Night code 6 Flash?
- Confirm the gas shutoff has not been moved and the furnace panel is fully seated.
- Try one reset and watch whether the burners light and then shut off again.
How much does Day & Night code 6 Flash cost to fix?
A flame sensor cleaning or replacement typically costs between $100 and $600 nationally.
When should I call a technician?
Call a technician if flame drops out again or ignition becomes delayed or noisy.
Sources and model scope
Fault codes vary by model and control board. Confirm the diagnostic chart inside your furnace panel or the official manual before acting.
Scope used here: ICP control boards covered by document 44001202103 and using its 2–10 flash table.
- International Comfort Products: Furnace Control Board Diagnostic Codes
44001202103 · ICP furnace control boards covered by document 44001202103; confirm the control-board label and door chart.
Compiled by Warmlo Editorial · Reviewed August 2026
This is general information, not professional advice. Gas, electrical, and combustion repairs can be dangerous — when in doubt, call a licensed technician.