I have a Lennox unit that continues to blow the fuse in the attic unit. Searching the internet I have cleaned the drip lines and replaced the contactor. The fuse continues to blow. When I push the button on the contactor the fan and compressor run. The control board was replaced last summer. What am I overlooking to stop the fuses from blowing?

Find the short

It only blows when it is turned to ac?

I have not tried to turn it to heat. So as of yet it has only blown when it cools. I can hear the unit upstairs begin to start and then it stops and the fuse blows.

Well first thing to do would be to put in a new fuse and ty the fan only, then the heat. This way we can elimonate some things.

Thanks Joshdta. I will see if I can get the fuse in tonight. I will update as soon as possible. Thanks