Kevin -
Did you see the post by AlRHall in the Plumbing forum that showed the underside of the tub area? You could see where the water pipes come out of the underfloor channel and into the tub area. I'm betting you could snake a heat tape through that channel, from the beginning of the channel under the kitchen sink, into the undertub area, to keep those supply lines from freezing.
It would be quite a project to do this, but I ran an electrical cable through the wiring channel (runs parallel to the piping channel), and it worked out OK. Since you don't want to pull up the tub, you would have to pull the converter out of the wall and work through that opening - that's what I did. It is cramped, but manageable.
As part of the project, you would have to seal up the openings in the floor under the tub. Specifically, the ones around the pipes would have to be sealed, probably with a piece of tarpaper or building paper and expanding foam. You would want to leave the vent fan opening clear, but then close it off from the outside during the winter.
I bet this would work. Of course, it would depend on the specific configuration details of your trailer in that area. Not a task for the faint of heart, I think.
Bill
|