I have to change the thermostat to ecobee thermostat. I am attaching pictures. I tried installing it, but cool mode is not working.
Can anyone please help me, how to wire this furnace? Is Ecobee compatible or not?
What kind of heating system is that? It looks like the old thermostat was a communicating type, so you need to re-wire the low voltage and use R, C, W1, G, Y1. If you only have 4 wires you need to use the PEK adapter.