Trane air conditioner does not respond to thermostat changes; system stays off or stuck in one mode.

Safety first: Turn off power to the indoor unit before removing the thermostat from the wall.

• Verify wiring: Compare thermostat wiring to the Trane installation manual. Ensure each wire is on the correct terminal.
• Configuration: Enter the thermostat setup menu and confirm system type (conventional vs. heat pump, number of stages) matches your Trane equipment.
• Reset thermostat: Perform a factory reset if available, then reconfigure.

If the system uses a Trane communicating thermostat, replacement should be with a compatible Trane model and may require technician setup.