It is definitely not the furnace, it is the water heater. I can see it underneath the stove, I just can't get to it. I already drained the water off from the outside, so I do know for sure that's what it is. I can't seem to post pictures, if I could it may clarify my situation. The way I see it, I could bypass the water heater to get to the kitchen sink, but that would be it without being able to access the line where it actually leaves the water tank to get to the rest of the trailer. All I can see is the pump and the line that leads back behind the oven to the water heater. From there, I can also see the line returning from the water heater to the kitchen sink. That is the only hot water line I can see.