Keeping the chickens' water ice-free during the winter can be a struggle.

The classic technique for full-grown chickens is the old bucket switcheroo: when you go out to tend the chickens, you bring out a galvanized bucket of warm water with you, and leave it for them to drink. You take away the partly empty bucket you left for them last time, which may have frozen. You bring the frozen bucket inside with you and leave it in a place where it will thaw a little, so the ice will slide out easily.

I think 10-qt galvanized buckets are the right size for this, though 12-qt butckets are okay if that's all you can find.

The water will freeze much more slowly if you provide some kind of insulated sleeve for the bucket (not styrofoam: chickens love to eat styrofoam). If you make a wooden float for the top, just a disc a little smaller than the bucket with a few 1" holes drilled in it, that will not only reduce the cooling rate, but will prevent the chickens from soaking their combs and wattles, which leads to frostbite.

Electric Birdbath Deicers

A more high-tech solution is to use electric heat. A lot of people use overhead heat lamps, in spite of the grotesque level of expense and overkill that this entails. ($54 per year if you leave a 250-watt bulb on for 90 days.) I like Birdbath Heaters combined with galvanized pet waterers. These thermostatically-controlled heaters use a lot less electricity, and all the heat goes to warming the water. I like galvanized pan waterers because mixing plastic and electric heaters makes me shudder. Sure, the heater has a thermostat, but I prefer not to trust such things fully. If you use a plastic waterer anyway, use a low-wattage heater. A 50-watt heater won't do much damage. I use 200-watt heaters in my galvanized waterers. 200 watts sounds like a lot, but mine only run when the hen lights are on, and in the morning the waterers may be frozen solid!

You can also use a thermostatic switch to keep the lamp off when it's not too cold.

I think attempting to keep the chickens warm (except during the brooding period) is a mug's game and I wouldn't spend a nickel on it. People in climates where temperatures fall below -20F might find it worthwhile, though.

You can also use heated waterer stands, which will work with a variety of waterers including the usual double-walled water founts. Me, I use automatic waterers when I can, and buckets when I can't, but lots of people like galvanized founts.

As for keeping the water flowing through the pipes, you're on your own. Here in Western Oregon, there are only a few days per year with daytime highs below freezing, so I run garden hoses everywhere and let them freeze and thaw as they please. On days where the hoses don't thaw, I carry hot water out to the waterers. This works fine if you use metal fittings everywhere and use waterers with metal valves, like the one above. These can freeze solid and not care. (Of course, I have to prevent my pump and PVC piping in the well house from freezing, but I leave the stuff on the pasture and in the chicken houses to take care of itself.)