Which Motorised Valve?

[Affick]

We have old Drayton (fused unit) motorised valves regulating CH and HW which need to be replaced. These are regulated by thermostats and power the boiler and pump. I want to use the Honeywell V4043 valve. However, I note that these have 'A Potential Free End Switch' to power the boiler and pump. What exactly does that mean? Does it mean that these valves (which I have bought) are not suitable for this purpose and that I should have bought the V4043H?
Many thanks for any help.
Affick

 

[chris watkins]

How is the old Drayton wired ? how many wires does it have & can you see there colours ? I take it that they are two ports ?

 

[Affick]

Thanks for your reply. The old Drayton Lifestyle valves are 5 wire but I havent looked at the colours. (Its like a spaghetti junction in there). THe V4043 is also 5 wire.THere are 3 valves, all 2 port (up/downstairs and HW).

 

[chris watkins]

Thanks for your reply. The old Drayton Lifestyle valves are 5 wire but I havent looked at the colours. (Its like a spaghetti junction in there). THe V4043 is also 5 wire.THere are 3 valves, all 2 port (up/downstairs and HW).

Are old Draytons spring return type (is there a lever on the side that can be used to open them, if you are not sure you can post a photo or get somebody in, if you are not confident with wiring these back up you can get in to all sorts of trouble.