Thanks for the replies!
Yes, the trailer is new. It's a 2019 that we purchased in July.
The minimum setting on the thermostat is 40, what would be a good temp? From experience with our old motorhome, I wasn't too concerned with anything freezing at or below 32 for a short time. Here in Northwest New Mexico, we have the widest temp swings from day to night of anyplace I've ever lived. A 30-40 degree swing from day to night is common, so everything warms up good during the day. But you are right, propane is cheap insurance!
Another thing I really like about the motorhome in comparison to the new trailer is that the plumbing all runs inside the coach, through the bottoms of cabinets, and even the fresh water tank is inside, under the dinette seats along the wall. So when the heat is on, everything stays thawed easily. I'm not familiar with how effective a "heated enclosed underbelly" is. That's a new thing to me.
As it turns out, I'm guessing at this point is was condensation. It dripped for a while, maybe one or two drips a minute, but then after a while it went away, and dried up. And that was with the water pump on and the system pressurized for hours. I even ran the water heater so see if the expansion of hot water would affect anything, but it still stayed dry. Strange!
I was mostly concerned because the drip was in such a unusual place, given there was no moisture on the walls either inside or out. I found no large area of wet surface anywhere to have caused that much water to collect. It almost would seem as if the moisture would have had to come from inside the wall panel itself. But given their construction, (I believe they are solid foam core?) I'm not even sure that is possible.
Only other thing I can thing of is that maybe there was condensation from the little bar fridge in the outdoor kitchen earlier, but by the time the water moved down to where it was dripping, it had already dried up around the fridge. Not sure though, since the fridge sits on a little pedestal covered in real thin carpet...seems I would have felt some moisture around there.
Sure is a mystery. And usually, I like mysteries...just not the water dripping kind.
