We have a new to us 2005 Jayco Jay series pop up. We cannot get the heater to work. It has an autopilot, and when we take the cover off the heater we can see it trying to light, the blower comes on, it tries for about 30 seconds, won't light and shuts itself down. The propane is on and working, the stove works great. The owners manual is no help, any ideas?? Thanks!