Heated water line compartment
Well, I learned something interesting that was a pleasant surprise! On our last camping trip, temperatures were running quite cool at night. The lows were around 34, which was borderline but OK. One night, the forecasted low was 33, but when I woke up in the morning the outside temperature showed 31. I didn't think this would be a problem, but the water at the toilet was only gurgling. Both faucets seemed to work fine. This seemed like an ominous sign to me that there might've been a little bit of freezing somewhere. I grabbed my infrared thermometer and went out to open the compartment containing the water pump, freshwater tank and various waterlines. The water pump registered at 64°, and everything in that compartment checked out at 45° or higher. Because the furnace was running, I could feel warm air blowing into that compartment. I did not realize the compartment was actively heated (I knew it was within the "heated" area of the RV, but assumed it was passive heating inside the insulated zone). This was really great to learn and see the real time temperature readings.
Having said that, the one area that is exposed is the line to the outside sprayer. Even though borderline 32° would not be much of a problem, one can never rule out a sudden freezing snap. Therefore, I did the best I could do stuff this with insulating material (of the type found in the laundry bag). Next time I would bring some better insulating material.
Returning to the story line, the question remained why the toilet water was only gurgling. Although I knew we were low on water, it turned out after trying the faucets further, we actually were OUT of water. Testing showed all faucets ran out. So we just had to add some water (another story...).
Pretty much a happy ending!
PS: the furnace worked like a charm and used little propane. After three cold nights plus cooking, we had used less than 1/2 tank. The heat pump worked OK down to about 40° but would freeze up after that. Also: (1) the heat pump is much noisier, and (2) the heat pump blows heat out of the ceiling vents whereas the furnace heat comes from the floor vents. The heat pump made it warm up where your head is but feet and legs were cold! The furnace does a much better job heating the entire unit from the floor up to the ceiling.
Land of 10,000 Lakes
2016 Forester MBS 2401R
Nights camped 2016: 32; RV to date: 35
2016 FR Forester 2401R
Towing 2014 Honda CR-V