frozen water lines

I also have a Hitchhiker, my second, and all of my water lines are above the floor. None run below the floor line except the line from the tank to the pump and it is still flowing since the pump is working.. The suggestion about the water inlet being frozen is probably accurate. Locate the inlet, which is probably in a basement area and put an electric heater there. Or just continue to use the pump until the weather warms or you move. I doubt that a heater under the unit will do any good, IMO.