HVAC experts give me advice please

[mxracerzero]

I just purchased a home and of corse the thermostat up and down buttons dont work so I am stuck with P.O. settings. I purchased a new one from filtrete that has wifi so I can change the temp with my Iphone. the only problem is it needs a C wire to work and I cannot seem to find out which wire that is or how to check the board inside the hvac unit to compare. it is a trane xb80. anyone have any ideas or helpfull info?

[mxracerzero]

never mind. I figured it out. thanks though.

[99WhiteBeast]

Please share solution- wanting to do the same this year

[SILVER2000SVT]

I just got through rewiring my whole system. The moron HVAC "Professionals" made so many mistakes the system never heated. Had been that way for 3 years before I bought the house.

[mxracerzero]

it was really easy I removed the front upper cover on the hvac unit and then removed the lower panel with the board inside. the board was labeled and the C wire was on the far end. the wire harness for the thermostat had a total of 8 wires and only 4 where used so I took one of the open wire and added it to the C wire port and boom constant 24v hvac power. the filtrete wifi thermostat is great! It wasnt very difficult to set up and I can adjust the temp anywhere(not only via wifi but also via 3g) with the app on my Iphone. it is also a better unit the the shlage link one and has no monthly fee. it also has a 5 year warranty so I recomend it highly so far!