Trane Furnace Continuous ON
Hard lockoutShown as: LED on solid, never blinking
The integrated furnace control (IFC) itself has failed. The manual's instruction for this pattern is to replace the control board.
Manual wording: “Continuous ON --- Replace IFC”
Documented for: *UH1 / *DH1 condensing furnaces (XR 95 family) and other Trane furnaces using the LED-only integrated furnace control
Likely causes, most common first
- Failed integrated furnace control board
What you can safely check yourself
- Turn the furnace switch off and back on once to confirm the LED really stays solid rather than flashing a code
When to call a technician
This is a board replacement. Call a technician; there is nothing a homeowner can do about a failed integrated furnace control.
A Trane furnace throwing this code repeatedly has a reason — clearing the code without fixing the cause just hides it.
Source
- Installer's Guide - Upflow/Horizontal, Downflow/Horizontal, Gas-Fired, Direct Vent Condensing Furnaces (18-CD29D1-14-EN) (Trane, *UH1B/*UH1C/*UH1D upflow and *DH1B/*DH1C/*DH1D downflow condensing gas furnaces (XR 95 family; first letter A or T)) · checked 2026-08-25