I have a Trane thermostat that is acting wonky. It won't let me change the temperature at all, and the backlight is not working. The backlight does come on if I remove the thermostat from the wall, but then it goes right back off and I still cannot change any settings.

I have changed the batteries. I have tried the reset button.

The thermostat model is tcont802as32daa. This is for a heat pump system. If I do need to replace it, can I use a Honeywell? They are about a third of the price of a Trane.

Thanks!