Used for Side wall venting commercial natural gas or LP fired equipment including : boilers, water heaters and unit heaters. All models feature the new UC1 Universal Control and a diaphragm Fan Proving Switch safety interlock which will shut down heating equipment if a venting malfunction occurs. UC1 Universal Control features include; adjustable pre and post-purge settings, LED Status/diagnostic indicators, Fan Prover switch monitoring. Interlocks with any 24-120 VAC burner control circuit and also includes "dry" contact actuation option. Easily interlock multiple appliances with our MAC-Series multiple appliance controls. Allows for a significant reduction in vent pipe diameter to save on costly materials and labor. Built-in adjustable damper also allows regulation for maximum combustion efficiency. .