Tekmar Boiler Control-4 tN4, BAS, 4 Boiler + DHW & SP. Boiler Control 284 is designed to operate up to four boilers to accurately maintain a target water temperature. 284 operates both condensing & non-condensing boilers that are eir modulating, single stage or two stage to provide a flexible, cost effective mixed boiler plant solution with better system performance. target water temperature is based on outdoor temperature reset or a fixed setpoint for space or process heating applications. Additional loads supplied by 284 include domestic hot water & fixed setpoint heating. Boiler equal run-time rotation, stand-by primary pump operation & pump exercising all increase boiler plant reliability. 284 communicates with a Building Automation System (BAS) using BACnet??or Modbus??for remote monitoring & adjustment capability. tekmarNet??rmostats or a tN4 Gateway 483 can be added to optimize system performance & provide remote monitoring capability.