Dry Run Cutoff Switch for Dankoff Booster and 2500 Slowpumps The Dry Run Switch kit is an optional accessory that prevents your pump from running without water. If the pump runs dry, it will get hot from the increased friction. Heat and Friction will damage the pump causing it to wear out quickly. The Dry Run Switch Kit fits over the front of the pump head assembly and disconnects the pump motor electrically from the pressure switch when the pump gets too hot for proper operation. Another advantage of the Dry run Switch is that it prevents the system battery from being drained while the pump runs dry. Kit Includes: Dry run detection thermostat, mounting clamp and wire nuts.