My trane unit is a Vertical Upflow Air Handlers.I attempted to turn my trane central air on at the thermostat by turning the power on and lowering the temperature, and NOTHING!! I automatically suspected that the circuit had tripped to I went to the breaker it was in the on position , so I flipped it and went back to the stat. NOTHING. I tried to see in increasing the temparature and turning on the heat would get something, and NOTHING!! The fan on unit is not on and there is nothing coming out of the vents, for either a/c or heat. I open the uint, change the fuse and nothing, and is making a humming noise what I need to replace

With tstat set to fan not auto does the fan work? If not you need to check and findout for sure if you have power at the unit

When you trying to cool,, is the outside condenser doing anything?