Years ago I purchased a used 5th wheel Me Too trailer that had water Lines that froze and the water heater also was damaged. So I purchased a water heater and figured all I had to do was remove the old and install the new and be done. What a shock it was when I found that the new water heater wouldn't hook up because the original water lines had expanded when it froze and ALL the water lines throughout the trailer were now just a bit larger in diameter. YES worry about the pipes particularly if they are copper. I realize that rvs nowadays use pex which is a bit more forgiving but I'd be concerned anyway.