In addition to providing a structured wiring system for zone thermostats and associated eclectrothermic actuators, the FH-WC also incorporates two voltage free heat demand relays that are activated when one or more zones call for heat. The two relay solution allows for separate control of a floor heating zone pump and a boiler. With this arrangement, the boiler may by used for normal radiator heating and hot water service provision, without the need for external relays.