[shrugs] It's not that bad, once you get used to it.
I grew up in Alaska, and heat plates either did not exist or my parents didn't know about them. We changed water twice a day all year long, with an extra time in the coldest winter weather. (Why twice a day in summer? Because Mom said so--it...
How many chickens do you have?
As long as they don't drink it all up before it freezes, there's no reason for big water containers in freezing weather--a dog dish may be quite big enough, or a chick waterer that holds a quart, or a rubber bowl you can easily break the ice out of.
Having two...
Maybe the heater changes the flavor?
Any chance they could have gotten an electric shock? That might be enough to make them stay away for quite a while, even if it only happened briefly.
Chickens do drink different amounts in different weather, so there's a chance their water needs really did...