I installed a Central Heating/hot-water system some 30 years ago that was based upon the Smith Switchmaster 805 controller.
There are actuated valves for both CH and HW and use Sunvic SM4203 actuators which have 4 wires coming from them. The cylinder stat started to cause problems so I replaced it with a Draper HS3 which has 3 wires and, foolishly, ignored the fact that one of the wires from the actuator should connect to the stat and the system does not work. Does anyone know of a suitable Cylinder stat that has 4 wires and would work with my current set-up.
CoinDJ76
There are actuated valves for both CH and HW and use Sunvic SM4203 actuators which have 4 wires coming from them. The cylinder stat started to cause problems so I replaced it with a Draper HS3 which has 3 wires and, foolishly, ignored the fact that one of the wires from the actuator should connect to the stat and the system does not work. Does anyone know of a suitable Cylinder stat that has 4 wires and would work with my current set-up.
CoinDJ76
