Goodman Furnace Code 8
Hard lockoutShown as: 8 flashes, then a pause, repeating
Igniter relay fault. The control board detected a problem with the relay that powers the hot surface igniter, so the furnace will not run.
Manual wording: “Igniter Relay Fault”
Documented for: Goodman GMES80, GCES80, GMSS92, GMSS96, GCSS96
Likely causes, most common first
- Improperly connected igniter
- Bad igniter
- Poor unit ground
- Poor burner ground
- Faulty integrated control module
What you can safely check yourself
- Turn the furnace off at its power switch for about 30 seconds and back on once to see if the code clears
When to call a technician
Igniter, ground wiring and control board diagnosis are technician work.
A Goodman furnace throwing this code repeatedly has a reason — clearing the code without fixing the cause just hides it.
Sources
- 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