I have an f500, that had some trouble with the rear burn tube falling out of I bump it while loading. I talked to the local dealer (I bought the stove from an individual out of the area) and they said their guys take the screws out that hold the tubes in so they can be removed without taking the stove apart for cleaning. I think I got the tube to lock in place, but while looking at it I noticed there's a big gap between the left manifold and the part it attaches to on the back of the stove. No gap on the right manifold. There's also a gap shown in the second picture. The dealer is booked full and won't come look at it. I'm guessing the manifold is warped. Any advice?