The Tekmarnet® 2 House Control 400 is Designed to Operate All of The Mechanical Equipment in a Residential Hydronic Heating System, Coordinating Their Operation With Network Communication. It Can be Used in Applications Ranging From a Single Zone of Baseboard With an On/Off Boiler, to Multiple Radiant Floor Zones With a Modulating/Condensing Boiler. This Control Regulates One Space Heating Water Temperature Through Outdoor Temperature Reset And Indoor Temperature Feedback. It is Capable of Controlling a Single On/Off, Two Stage, or Modulating Boiler, Domestic Hot Water, Setpoint Loads, 4 On-Board Zone Valves, And Can Expand up to 24 Zones in Total. For Further Information And up to Date Literature Visit: Tekmar Documentation | Tekmar Controls | 400