“With a floating trough heater “young” or “mouthy” horses will play with them like bath toys, chewing on them or ultimately flipping them our of the trough and onto the ground. Also, because heat rises, this type of heater does not work well on deeper troughs in extremely cold climates. Ice will still form at the lower depths, keeping the overall temperature colder than ideal.
A short in the system could cause the unit to quit working. Worse, it could electrify the water, creating a shocking effect when your horse tries to take a drink….And of course, make sure electrical cords are well out of reach. If a horse chews through an electrical cord, it may be the last thing he ever chews on!” (November 2000 issue of Horse Illustrated)