Ray,
Yes my basement bays
are heated and I was surprised to find the water pump frozen that one time. I just wrote it off to the lack of circulation in that area on that side of the partition and being so close to the bay door... It was also during a time when I was using electric oil-filled space heaters to augment my interior heating to keep the noise down when I slept and that certainly could have been a factor in allowing the basement bays to be cooler than normal. My basement heat ducts are much smaller than the ones in the living spaces and are about 2 inches in diameter, made of a heavy foil over a spring wire open coil just like the larger sizes of ducts.
I have also heard of winter coach users having the filtered water line to the residential refrigerator ice maker freezing on occasion -- can't recall if that was while moving at speed (which would increase the wind chill on the outer coach body panels) or while parked. THAT has never happened on my coach -- at least not yet (probably should not have typed that out loud --
)
Chuck