Examined unit. Turned on. Cycles. Blower running. Opened control panel. Found new interface board 12v. Light is lit. 24v 6v and power not. Will need new multivolt transformer. Will order and return. 3-6-17 Examined unit. Replaced multivoltage transformer and tested. Turned on, blew fuse on board. Traced back to ignition module. Replaced module. Installed new fuse and tested. Unit cycled and came up to temp.