My guess is that it has to do with power to the fan. Either there is a blown fuse or no (or not enough) power to the fan. And I agree that there should be no pilot light. It should be an electronic igniter. By the way, my furnace will light and the fan will come on even if it is 85 degrees in the pup. I know, because have turned it on to see if there was propane running to it.