Hot water heater moving out

On a prevoius pop-up I had there was a leveling block under the tank. Maybe your has rolled over. On my trailer the screw attaching the block to the floor went into the tank after it rolled over.

No. The gap remains; only at the top. :-(

vandave wrote:
Thanks. I've tightened the four long screws but there remains a gap at the top.

Did the top 2 actually tighten?

There should be NO GAPS otherwise water will get in and cause wood rot, delamination, mold/mildew etc.

Flush mount means exactly that...FLUSH.

Thanks. I've tightened the four long screws but there remains a gap at the top.

Frame mounted will have 12 screws to secure it to side of trailer

Flush mounted will have 4 long screws that go thru brackets (2 on each side top/bottom) to secure it to side of trailer

Some flush mounts have 1 long screw on each side towards bottom thru a bracket and then have 2 more screws on top from inside

If you have a frame mounted it would be very obvious when you open outside access door.

Flush mount you need to look closer when you open the access door.

My first thought was rotten wood, only that should be an Aluminium framed rig.
They are usually attached from the front via several screws into the framing around the water-heater. Have you checked those screws?