Tekmar’s Zone Valve Control 306V provides heat to hydronic heating systems by connecting as many as four thermostats and operating various zone valves. Designed to operate zone valves and a system pump, the control includes optional exercising and post-purge operation of domestic hot water tanks, as well as RoomResponse technology for adjusting boiler target temperatures based upon thermostat on time. It features unlimited zone expansion and is compatible with all 24 V(ac) thermostats as well as  two-, three-, and four-wire zone valves.

Tekmar. www.tekmarcontrols.com