Career air conditioner furnace not working. I have already reseted power few times. The thermostat is working fine and I checked batteries too. What else I can check? I hear some humming sound, like something is trying to start but can not.

Is the fan running??

No. Not even fan is running.

Check fuse at furnace, breaker to furnace, and then maybe the transformer.

Thanks. I checked the fuse. It was blown. Before that I checked the LED Status code and it was 24 which is "Secondary Voltage Fuse is open.". I replaced the fuse. However, the new fuse blown as well. Please advise what can be the problem.

If it is blowing while trying to run the ac could be a bad contactor outside. If not may just be a pinched wire or a short inside.