Trane S8X1 furnace code E6.1: Reversed polarity
Professional repair
What does E6.1 mean on a Trane S8X1 gas furnace display? E6.1 means the control detected reversed line-voltage polarity at the furnace power supply. It is an electrical supply fault, not a burner fault.
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Measuring and correcting line-voltage polarity is work for a qualified technician or electrician. No homeowner wiring changes should be attempted at the furnace or its supply.
Possible causes
- Line and neutral conductors swapped at the supply 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 E6.1 mean on a Trane S8X1 gas furnace display?
E6.1 means the control detected reversed line-voltage polarity at the furnace power supply. It is an electrical supply fault, not a burner fault.
How do I fix Trane S8X1 furnace code E6.1?
Have a technician or electrician confirm the polarity and correct the supply connection, then verify a normal heat cycle. Mention any recent electrical work in the home. Do not open the junction box yourself.
How much does it cost to fix Trane S8X1 furnace code E6.1?
Cost reflects the visit and time to measure and correct the supply wiring. The code itself does not imply a failed furnace part.
Applies to
S8X1A040M3PSCA · S8X1B040M2PSCA · S8X1B060M4PSCB · S8X1B080M4PSCB · S8X1C080M5PSCA · S8X1C100M5PSCB · S8X1D120M5PSCA
Different Trane 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.58
Verified against Installation, Operation, and Maintenance — Upflow/Downflow/Horizontal Gas-Fired,1–Stage and2–Stage Induced Draft Furnaces with High Efficiency Motor, p.71
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 Trane furnace codes
These codes use the same trane s8x1 single-stage furnace control display (2024 iom) system.