In a hydronic radiant floor heating system, what device works with the thermostat to provide individual zone control?

• A. Telestat
• B. Thermostatic radiator valve
• C. Zone valve
• D. Hydronic circulator

Answer: (A)

Zoning in a radiant floor system relies on a controller that interprets each thermostat’s demand and directs heat to the appropriate area. A telestat is a multi-zone control that connects to several room thermostats and switches the corresponding zone valves or circulators on or off. This lets each zone reach its own setpoint independently, so only the areas that need heat are heated. The actual zone valve or pump handles the flow for a single zone, but it’s the telestat that coordinates multiple zones by responding to the thermostats. Thermostatic radiator valves and the circulator by themselves don’t provide multi-zone coordination in a radiant floor setup, so the device that works with the thermostat to enable individual zone control is the telestat.