When I kick the heat on, the furnace heats air but doesn't blow it out. The fan works when I kick it from "auto" to "on" (to blow in air from outside). If I've had the heat on before switching it to "on," hot air comes out at first, indicating that the furnace IS heating air, just failing to blow it out. Since the fan runs no problem when I switch it to on, I'm assuming the problem is with the relay, or the fan and limit control. I know little on the topic. Am I on the right track here? My furnace is a Janitrol electric (can't find a model number, house is 17 yrs old). I tried flipping breakers, and inspected the wiring (everything looks good). Thanks for your help.