Computer Watchdog Circuit Automatic Drain/Flush System Highest Efficiency Rating than any other Humidifier Automatic Maintenance Mode 100% Guaranteed NO Summer Maintenance Interlocking wiring for Fan Control Humidifies without a call for Heat LED\'s for system readout Most Effective Cure for Dry Homes Listed and Approved by UL Compatible with all Heating Systems The Most technologically advanced Humidifier has become better with the help of a computer. The S2000 and S2020 Steam Humidifiers have a built-in computer chip to insure maximum efficiency, accuracy, reliability and safety. The Automatic Flush system will drain the humidifier every (12) twelve hours of operation. This is a preventative maintenance mode to help protect the homeowner from a lack of efficiency. The humidifier will completely empty itself and not refill until another call for Humidity. This mode insures that all Summer long, when the humidifier is not in operation the unit will not be full of water. The ONLY humidifier that will operate in the Heating system without a need for a heat call. The Steam Humidifier will operate and turn the Fan on independently of the Furnace. The Ultimate operation for Maximum homeowner comfort. The LED read-out display on the front cover shows the proper operation of the unit. The display also shows the installer and homeowner the effectiveness and the reliability of the unit. The UL label enforces EWC\'s commitment to product reliability and safety. Underwriters Laboratories (UL) is an independent auditing agency that rigorously tests the performance of electrical devices. Their seal is a symbol of Excellence. The Steam humidifier will work on any heating system. The S2000 and S2020 are compatible with all makes and all models of Forced Air Heating Units. The Steam humidifier is the Only humidifier that will work to its fullest capacity on Heat Pump systems.