AutoBoosterâ„¢ tankless electric water heater boosts tank water heaters by adding up to 45% delivery capacity to any tank. AutoBooster works with the tank to deliver more hot water. An 80-gallon tank combined with an AutoBooster delivers the hot water capacity of a 120-gallon tank. Install the unit directly on the tank outlet or on a nearby wall. No need for additional electrical infrastructure when used with an existing 30-amp electric water heater.