Trane Furnace Code E6.3
Hard lockout
Igniter fault. Either the igniter relay on the control has failed or the igniter itself is open (burned out).
Manual wording: “(1) Igniter relay fails (2) Igniter open”
Documented for: S8B1, S8V2, S9V2 and S9V2-VS furnaces
Likely causes, most common first
- Igniter relay fails
- Igniter open
What you can safely check yourself
- Turn the furnace switch off and back on once to see whether the furnace attempts to light
When to call a technician
Call a technician. A hot surface igniter is fragile and lives in the burner compartment; replacing it or the control board is not a homeowner job.
A Trane furnace throwing this code repeatedly has a reason — clearing the code without fixing the cause just hides it.
Sources
- Installer's Guide - Upflow/Downflow/Horizontal Left/Right Gas-Fired, Single Stage Induced Draft Furnaces with High Efficiency Motor (18-CE09D1-1E-EN) (Trane, S8B1A026M2PSAB through S8B1D120M5PSAB single-stage 80% induced draft furnaces) · checked 2026-08-25
- Installer's Guide - Upflow/Horizontal and Downflow Gas-Fired, Direct/Non-Direct Vent, 2-Stage Condensing Variable Speed Furnaces (18-CE01D1-1E-EN) (Trane, S9V2B040U3PSAA through S9V2D120D5PSAA two-stage condensing variable-speed furnaces) · checked 2026-08-25
- Installation, Operation, and Maintenance - Gas-Fired 2-Stage Condensing Variable Speed Furnaces with Variable Speed Draft Inducer (FNR-SVX001B-EN) (Trane, S9V2B040U3VSBB through S9V2D120D5VSBB (S9V2-VS) two-stage condensing variable-speed furnaces) · checked 2026-08-25
- Installation, Operation, and Maintenance - Link Communicating or 24 Volt Gas-Fired 2 Stage Induced Draft Furnaces with Variable Speed Motor (FNR-SVX003A-EN) (Trane, S8V2A040M3PCB through S8V2D120M5PCB two-stage 80% induced draft furnaces (communicating or 24V)) · checked 2026-08-25