American Standard S8X1 furnace code E6.3: Igniter circuit fault
Professional repair
What does E6.3 mean on an American Standard Silver S8X1 gas furnace display? E6.3 means the igniter relay has failed or the igniter is open. The detailed diagnostic page also covers a relay stuck closed and an igniter circuit that is open or shorted.
Before you touch anything: the six signs that mean stop troubleshooting and call a pro →
Igniter and relay testing require live measurements inside the furnace. A technician separates an igniter or wiring fault from a control relay fault before replacing parts.
Possible causes
- Open or shorted igniter or igniter wiring TECH
- Igniter relay on the control failing or sticking closed TECH
Parts for this code
No model-verified part number is listed here. Have the fault diagnosed and the correct part matched to your furnace before ordering.
Questions about this code
What does E6.3 mean on an American Standard Silver S8X1 gas furnace display?
E6.3 means the igniter relay has failed or the igniter is open. The detailed diagnostic page also covers a relay stuck closed and an igniter circuit that is open or shorted.
How do I fix American Standard S8X1 furnace code E6.3?
Book service and note whether the furnace starts its sequence but never lights. The technician tests the igniter, wiring and control relay, then replaces only the part that fails testing. Do not handle the igniter.
How much does it cost to fix American Standard S8X1 furnace code E6.3?
An igniter or wiring repair and a control replacement involve very different parts and labor. Diagnosis determines which applies before any estimate.
Applies to
S8X1A040M3PSCA · S8X1B040M2PSCA · S8X1B060M4PSCB · S8X1B080M4PSCB · S8X1C080M5PSCA · S8X1C100M5PSCB · S8X1D120M5PSCA
Different American Standard generations use different code maps. If your series isn't listed, don't assume this meaning — check your blower-door label.
Verified against Installation, Operation, and Maintenance — Upflow/Downflow/Horizontal Gas-Fired,1–Stage and2–Stage Induced Draft Furnaces with High Efficiency Motor, p.59
Verified against Installation, Operation, and Maintenance — Upflow/Downflow/Horizontal Gas-Fired,1–Stage and2–Stage Induced Draft Furnaces with High Efficiency Motor, p.73
Verified against Installer’s Guide — Upflow/Downflow/Horizontal Gas-Fired,1–Stage and2–Stage Induced Draft Furnaces with High Efficiency Motor, p.58
Last verified 2026-10-07 · page updated 2026-10-07 · how we verify
Related American Standard furnace codes
These codes use the same american standard silver s8x1 furnace control display (2024 iom) system.