I've discussed the problems with our water supply on other pages (going into the tank to clean it, new water tank, watershed) but the most recent pages end just after I finished installing the new tank.
Last winter the outlet pipe that transitions from the base of the tank inside the watershed to the warm garage froze several times. I eventually installed heat tape, but that proved ineffective. Each time it froze I had to disassemble the piping and heat the area with a heat gun until the slug of ice slid out and flow was restored. Not a fun activity at 5 AM when all I want to do is wash my face and make coffee.
This year I tried a new technique -- creating an insulated box around the opening to reduce the cold air flow and a small computer fan to gently blow warm air into the insulated area. I installed an indoor / outdoor thermometer in the insulated space with the probe extending into the shed. As winter approached, the temperature in the shed started declining, but the insulated area stayed right around 50 F.
Yesterday I put my beer thermometer into the insulated area on a whim. The indoor / outdoor thermometer read 48 F in the insulated area and 36 in the shed. But my beer thermometer was reading 30 F! Turns out the battery was close to dead in the thermometer I'd been trusting; the temperature in the shed was actually 26 F, and the temperature in my insulated area was down to 30 F.
I quickly upgraded the fan, and as you can see from the image, it's still 26 F in the shed, but it's a comfortable 52 F inside the insulated area. All the water in the shed has enough thermal mass that it can be below freezing for weeks (by which point it'll be filled again with warmer water) without freezing except around the edges. And the outlet pipe is now a steady 50+ F.
Just goes to show that you shouldn't put too much faith in a single instrument. It hit -34 F in Fairbanks this morning, and if I hadn't noticed it, the outlet pipe would surely have frozen.