I woke up around 4:30AM feeling slightly cold, couldn't get back to sleep so I got up and did a check of the heater and to see what the temperature of the water from the fresh water tank was at. I did notice the thermometer on the dinette table to be 48°F (8.8°C), this was lower than the 61°F (16°C) that I'd gone to sleep with.
I turned on the water pump, opened a faucet but only a little water flowed out. Hmmm. I didn't hear the water pump kick in as usual. Hmmmm. I used the touchless thermometer and found the piping under the bathroom sink to be in the low 20s!
Went into a bit of a panic and without taking a reading from the battery (dammit) I turned on the generator so I could run the tank heat pads. I also kicked on the coach furnace and blower, running both on high to bring temperatures up.
I thought, you see, that something had frozen and worried the pump had failed due to frozen water. Or worse, the water in the fresh water tank had frozen (it was 10°F (-12°C) as forecasted) and had cracked open, resulting in no water.
While troubleshooting I verified no big frozen puddle of water under the fresh water tank. The fact the pump wasn't working was worrying. After about an hour and half of mucking about, I tried removing one of the two power leads to the pump, checking for power with a multimeter, and reconnecting it.
Whether it was me removing/re-engaging the lead or things had warmed up enough by then, the pump kicked on when I tried it next. Hurray! Still, barely a few drops of water came out. Hmmm.
At this point it was after 6AM so I decided to pack things up, tie Scarlett down in the trailer, and get setup for travel, hoping that as the day warmed up, water would start flowing again. I decided, in contravention of safety practices, to drive with the propane valve open so I could run the coach furnace as I drove to help things heat up.
Here's the view as Uma and I, with Scarlett in tow, exited the area along county road 375:
Dawn along the Collegiate Peaks
I drove down towards Salida, the idea to take US50 East towards Colorado Springs via Cañon City. The CDOT site, cotrip.org, reported that route as dry vs US285 which was shown as "frozen".
At the Chalk Cliffs Overlook, I pulled over and posed ScooterBob for at least one picture for this trip:
ScooterBob with Mount Princeton (I think)
The rest of the drive was just highway driving with no weather issues. I checked the water flow when I got home and it poured out of the faucet, under the water pump's impetus, just fine!
So, that's the mystery that had been puzzling me since the first boondocking trip Martha and I had done where we'd seemingly run out of water unexpectedly. It was then, as it was this time, that water had frozen somewhere in the fresh water plumbing!
I am lucky that nothing froze to the point of bursting!
Next time we go boondocking, I now know that neither the coach furnace nor the Wave 8 Heater keep things warm enough to keep the fresh water flowing. We need to "winterize" the fresh water plumbing and use pre-stored water inside the coach for washing, cooking and flushing. The grey and black water tanks can be used, with periodic addition of RV Antifreeze deposits as liquid levels in each tank grow.
If we're in an RV Park with electrical hookups (which allow the running of tank heat pads and perhaps a small electric heater aimed at the plumbing under the bathroom sink); then it should be OK to keep water in the fresh water tank (disconnecting the city water hose at night).