I’ve been heating a couple of weak hives now for 13 days. They’re snowed in, but I’ve been feeding them 1:1 syrup and tap water. So far they’re looking good, but I won’t really know how it’s going for at least 21+ days. We had record heat last March, but so far we’re running about normal this year.
My heaters are 36watts. I'll turn down the wattage when our day temperatures exceed the freezing point.
With Edwards 100watt heater I could probably bake cookies in my hive :-D