Condensate Switch - Elbow. DiversiTech Flood Prevention Switches are simple to install, easy to service and extremely reliable. As water level in the auxiliary or main drain pipe rises due to a clogged air conditioning condensate drain, the switch shuts off the system—thus preventing water from overflowing and causing damage to doors, walls and ceilings. At the heart of the switch is a durable yet precise magnetic reed switch. Constructed of materials that will not rust or stick, the switch operates smoothly every time.