Here is what I finally came up with for our winter chicken waterer. It is a large heated water bowl, with a Buddy Bowl inserted inside. The Buddy Bowl allows me to remove the water container without dragging the heated water bowl out of the coop. The small opening also helps keep the water clean from flying debris and the girls took to it right away. It got down to the low 20's last night and the water was not frozen when I checked on it this morning at 4:30 a.m.
I also ran the cord for the heated water bowl under the edge of the coop and through a piece of flexible downspout extension out to fence, so no one pecks on the cord.
Paula
Farmgirl Sister #3090 Yesterday is History, Tomorrow is a Mystery, and Today is a Gift.