Tight Lines
Senior Member
Most HVAC systems, at least reasonably modern ones, have a breaker for both the air handler and the compressor, as well as a switch at the air handler and a disconnect at the compressor. The thermostat doesn't have the ability to turn them on or off from a power perspective, it can just activate them. It is a relay in effect. I would turn them all off for 5 minutes, including the thermostat if it is an electronic version, then turn them on and set the thermostat to a few degrees cooler than the house. Within a few minutes it should kick on...