As long as this question is being discussed, I was very curious what it would take to retrofit a coach that didn't come equipped with it already to have the tank heaters and water line heaters?
Sent from my iPad using Tapatalk
The underbelly (coroplast) has to be removed to gain access to the holding tanks and fresh water lines. The tank heating pads are about $150 each for a 40 gallon tank. They're dual voltage so you can elect to run 120V AC wiring or 12V DC wiring. While the coroplast is down, it's pretty easy to add heat tape to the fresh water line, along with insulation. And it would make sense to also protect the kitchen water lines.
Depending on the tank positioning, installing the tank heating pads could be easy. But on some floor plans, the black tank is above one of the gray tanks making access difficult.
If you're going to all this trouble and expense, I'd suggest heat tape on all your water lines. The cost of heat tape and controllers is low compared to heating the tanks. And once the underbelly is open, everything is much easier.