We bought the trailer new in November of '09 from the dealer in Spokane. When the 12v
water pump was used, the plastic water pipes would thrash between the side of shower and the exterior of the trailer. The noise could be heard in the next campsite. The dealer said he had worked on it, but nothing changed. I fixed it myself by doing the following:
1. Remove the heater vent on the outside of the trailer.
2. Remove two heater mount screws and remove heater. Mark all wires.
Cut the white one and splice when reinstalling.
3. Remove lower panel surrounding the heater. (6 screws)
4. Trace hot and cold water pipes up between shower and exterior. It's tight
in that space. If you're a big guy, get someone skinny to do it.
5. Using a can of minimal expanding polyurethane foam with a two foot
spout attached, spray the pipes up and back as far as you can reach.
6. Let the foam set for a day before testing.
Following these steps, my pump sound is normal now. I some how blew a heater fuse in the process.