I have a Lennox G20Q2E that appeared dead. The 2 amp glass fuse was blown. I replaced it and the fuse remained good with no call for heat. Stat called for heat and the electric damper started to open then the fuse blew and the wall stat started to smell of smoke. I dont see many Lennox products and have seen none with a motorized damper. Is the relay board causing the fuse to blow or is one of the devices hooked to it loading it down? Why did the stat heat up so fast? Why does this natural draft unit have a motorized damper? thanks for any help!!!