Took my 5er out from its winter cover to prep for the first trip of the season. All systems seem a go except for the hot water heater. The pilot lights
fine (it's an Atwood) but instead of the usual whoosh that sounds like a jet plane taking off I'm getting flame running down the tube and I can see flame in the vent that comes out of the unit! Tried it more than once with the same result. Shut it off and am wondering what I should be looking at first. I'd appreciate any thoughts - I'd prefer not to blow up the trailer or myself!