Honeywell Central Heating Cooker Natural Gas - Manual (Page 29)

29
WIRING ‘S’ PLAN
Independent control or space and water heating circulation in a
fully pumped system with two motorised valves (see System
Diagrams 1 and 2)
This scheme provides the optimum degree of control over a fully
pumped installation. Seperate two port motorised valves are fitted
in the space heating and water heating circuits controlled by room
and cylinder thermostats respectively
The method of operation is that if either the room or the cylinder
thermostats call for heat, they open the motorised valve
controllong their circuit. The auxiliary switch in the valve switches
on both pump and boiler. When either thermostat is satisfied, its
motors shut and the auxiliary ceases to provide power fot the
pump and boiler. When thermostats are satisfied, both valves will
be closed and the pump and boiler cannot run because their
auxiliary switches have opened.