Hello all. I have a 2014 CrossRoads Cruiser Aire travel trailer. The heater worked fine last year for winter. We left it unplugged all summer and now the heater won't fire up. We have power to the unit, but it won't fire. It's in a bottom compartment below the pantry and kind of hard to get to. I don't see any way to take it out like I've seen on YouTube so that we can take a look at it. Any ideas?