Unknown to some, the plastic piping under the Jayco floor is poorly insulated. In my mind, Fibreglass at 1/2" thickness does nothing. Thus, assume NO insulation around its under floor (between its 2x2 floor boards) piping, its ABS discharge pipes and around its hot water heating system.
For pictures, surf:
http://i178.photobucket.com/albums/w251/Spike99-Pictures/Seasonal Camp Site/100_2054.jpg
http://i178.photobucket.com/albums/w251/Spike99-Pictures/Seasonal Camp Site/100_2048.jpg
http://i178.photobucket.com/albums/w251/Spike99-Pictures/Seasonal Camp Site/100_2056.jpg
Even the gooseneck under the bathtub has very little insulation. IMO, a heater inside the TT cannot properly heat "below its floor" and "inner storage compartment" pipes. Even setting heater to 75 F, I bet those under floor items are still at freezing temps (when outside temps drop below freezing).
Within this in mind, I would "winterize" the TT when its temps drop below freezing. Its plastic pipes and joints cannot take freezing abuse. The above pictures are proof...
Hope this helps...
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