Alright guys when it comes to HVAC I don't know anything about it. That's the part I sub out! I know someone here can point me in the right direction. My entire unit stopped working so I checked the transformer for 24v and there was nothing. I went to get a new one and I put it in. My unit came on for a few seconds then went off and the transformer was smoking and now is blown again. I checked my thermostat, it works. My old transformer had a fuse in line on it and the new one didn't and I didn't put one on it. Could it have blown because of this or did I hook up the wires wrong? Possibly a short in my thermostat wire? I appreciate any advice, thanks.