Trane Furnace Code E06
Warning
Line voltage polarity is reversed at the furnace, or the furnace is not properly grounded.
Manual wording: “Voltage reversed polarity or Bad Grounding”
Documented for: S9V2-VS furnaces (FNR-SVX001B control revision)
Likely causes, most common first
- Voltage reversed polarity
- Bad grounding
What you can safely check yourself
- Note whether the code appeared after electrical work or after the furnace was run on a generator
When to call a technician
Call a technician or electrician to correct line polarity and grounding at the furnace.
A Trane furnace throwing this code repeatedly has a reason — clearing the code without fixing the cause just hides it.
Source
- 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