I just bought the HoneyWell Wifi thermostat and so wanna use it. However my old Thermostat was battery powered and does not use the "C" wire. I opened up my panel and found that there were three unused wire. a brown color, an orange color and a blue color wire. One by one I plugged each into the "C" terminal of the honey well wifi thermostat (R, W, G are already plugged) but none of them worked. I tried plugging G into C but it didn't work (my cooling isn't gas or propane powered but is electric. Maybe that's why). The thermostat doesn't turn on. What should I do? Should I buy a 24V power adaptor and plug the power chord into C. I don't wanna do it as there would be a wire hanging outside thermostat. Do I have any other option?
P.S I don't have a cooling circuit board. All I have is an on / off circuit breaker.