Goodman Furnace Code 7
WarningShown as: 7 flashes, then a pause, repeating
Low flame sense signal. The furnace is still running normally, but the flame sensor current has dropped low enough that the control is warning you it is about to start failing to light.
Manual wording: “Low Flame Sense Signal”
Documented for: Goodman GMS8, GMH8, GDS8, GDH8, GHS8, GME8, GMES80, GCES80, GMSS92, GMSS96, GCSS96 (single red diagnostic LED)
Likely causes, most common first
- Flame sensor is coated or oxidized
- Flame sensor incorrectly positioned in the burner flame
- Lazy burner flame due to improper gas pressure or combustion air
What you can safely check yourself
- No homeowner action - the furnace is still heating. Schedule service before the code turns into a 1-flash ignition lockout
When to call a technician
Cleaning and repositioning a flame sensor means working inside the burner compartment of a live gas appliance. Book a service call.
A Goodman furnace throwing this code repeatedly has a reason — clearing the code without fixing the cause just hides it.
Sources
- Installation Instructions for *M(H,S)8 / *D(H,S)8 / *HS8 / GME8 Gas Furnace (Category I) - IO-359J (Daikin Comfort Technologies (Goodman brand), Goodman GMS8, GMH8, GDS8, GDH8, GHS8, GME8 80% AFUE gas furnaces) · checked 2026-08-25
- Installation Instructions - *MES80 / *CES80 Gas Furnace, Category I - IOG-2021H (Daikin Comfort Technologies (Goodman brand), Goodman GMES80, GCES80 80% AFUE gas furnaces (PCBBF145 control board)) · checked 2026-08-25
- Installation Instructions for *MSS9* & *CSS9* Single-Stage Gas Furnace - IOG-2009Q (Daikin Comfort Technologies (Goodman brand), Goodman GMSS92, GMSS96, GCSS96 single-stage 92/96% AFUE gas furnaces) · checked 2026-08-25