My central A/C unit is not working at all. I have checked what I can i.e... Thermostat set to cool, below ambiet temp. All breakers are fine and not tripped. I tried setting the fan to the "on" position and air handler did not come on. The float swith is not activated (no standing water in line) On the out side unit nothing is running. Outside breaker is not tripped. Ugghh. Please help!