Thanks for your help in advance. I have a dead short on my furnace. It only blows when the Stat is set to heat. I've removed all the wiring fron the stat as recomended on another post. The only short I have been able to trace is at the com, there is a blue and white wire at this connector, I've disconnected these wires and my ohm meter reads dead short . any ideas or what should be my next step? Thanks again.