Spring return zone valve

[billychuff]

Can anyone help me and let me know why these valves need a permanent 230V supply? Many thanks

 

[tamz]

The valve itself does not need a permanent live to function. The permanent live is for the microswitch (grey and orange wires). When the valve motor opens (powered by the brown wire) it makes the microswitch which sends power to the boiler/pump. This allows different circuits to open and close independent of each other and the boiler still to be powered.
If there is only 1 motorised valve used the grey and orange are not needed.

 

[Puddle]

1 .To keep them open in some instances if permanent live connected to syncron motor ie if we have a high limit stat in line,if system over heats,limit stat disconnects and valve closes

2 To allow two separate circuits,to stop back feed power supply which would interfere with other controls/valves on system when activated and turn them on also,this allows as many zone valves as you like on the system to operate independently and to make sure valve fully open before boiler,pump comes on line,although latter could be done with single power supply
Switch live through programmer and room/cylinder thermostat valve(s) opens valve and activates micro switch ,permanent live connected to micro switch and when activated operates boiler,pump,ect

We separate supplies by a micro switch in the zone valve or in some instances relay box's are used

As Tamz says,sorry went for me dinner !!