Tekmar 423 Universal Reset Module, Four tN4, Two Boiler, DHW and Setpoint

The Universal Reset Module 423 is designed to operate all of the mechanical equipment in a hydronic heating system, except for zones, coordinating their operation through network communication. It can be used in applications ranging from a single zone of baseboard with an on/off boiler, to four temperature systems comprised of multiple fan coils, baseboard, mixed radiant floor zones, and two modulating/condensing boilers. This control regulates up to four space heating water temperatures through Outdoor Temperature Reset and Indoor Temperature Feedback. It is capable of controlling two on/off or modulating boilers, Domestic Hot Water, setpoint loads, and can expand up to 24 zones for each space heating water temperature (96 in total). Features: Outdoor temperature reset, indoor temperature feedback Warm weather shut down, zone synchronization DHW post purge, DHW control DHW priority (optional), setpoint operation Expandable up to 96 zones, two on/off or two modulating boiler control Controls up to 4 water temperatures (with use of up to 3 mix expansion modules), automatic boiler differential Exercising, boiler protection Powered pump outputs, system setback (with optional timer) One touch overrides (with optional User Switch)