I have an ArcoAire 2.5 ton ac/gas heat unit, and when my husband installed it and hooked everything up, it will not come on when set by the thermostat. The unit will run, and the compressor works fine, but only when the button on the control panel itself is compressed. He has tried changing out the interior thermostat, and changing the circuit board, but to no avail.

He has also tested the coil and transformer, and all are working fine. He just cannot find what is missing between the thermostat and the outside unit... please help, it is getting warm in here.:(

Does the heat work?

He has just gotten it to come on by replacing the digital thermostat with a standard one. Thank goodness, thought I was going to have to move... lol

The problem probably was there was no jumper wire from rh to rc on the t-stat

Glad you have it working.