Honeywell motorised valve wiring

First thing to make clear is am not an electrician or plumber. I would really appreciate the advice being non-technical.

I have a central heating system with 2 Honeywell V4043H1C56 actuators.

The hot water one (nearest the immersion) is working fine but the other which controls the hot water going to the rads sticks & therefore needs to be replaced.

First thing to make clear is that it is old & therefore I am having to replace the actuator & install the converter plate as it is not the more recent all in one model. Therefore I do have to drain the system.

Problem & therefore advice I need concerns the wiring. The currently fitted old model has 5 wires, the new model has 6, the most noticeable difference being an extra white wire.

Wiring in the cupboard is as follows - Colour at the start of each line is the one from the current actuator

Blue & a 2nd blue feeds into to wiring block with a Blue, Blue & Black on the other side of the wiring block.

Grey & a 2nd grey feeds into a Blue & Brown on the other side
Green with yellow stripe & a 2nd Green with yellow stripe feeds into 2 Green with yellow stripes on the other side

4.Red & a 2nd Red feeds into a Red on the other side

5.Black is joined together with one yellow wire

This leaves two questions for installation of the new actuator-----

Do I use the brown wire on the new actuator in the same way as the black in the previous & what do I do with the white wire in the new actuator ?

Many thanks for anyone who can give me help.

Neil

You first need to understand a bit about how your system works - then it becomes easier to work out how to wire it.

You have an S-Plan system (see

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for information about the various 'plans')

The principle of operation of S-Plan is this: You have one motorised valve for each zone. (You have 2 zones, one for HW and one for CH) Each motorised valve is controlled by the programmer and a zone thermostat - (Room stat for CH and cylinder stat for HW) - and the zone valve will open when the appropriate zone stat is calling for heat (assuming it's also on at the programmer).

Inside the actuator of each zone valve is a switch, which is totally independent of the motor circuit, and which closes once the valve is open. This switch is used to switch on the boiler and pump once a valve has closed. The switches in both valves are wired in parallel so that the boiler will run whenever at least one valve is open (but water will only circulate in zones whose valves are open - so you can have HW without CH or vice versa).

In S-Plan systems, the switch which closes when the valve opens only needs to be a simple on/off switch with 2 wires going to it. On the other hand, a C-Plan system requires a change-over switch where the input is connected to one or other output depending on the switch state. Such a switch requires 3 wires.

The actuator which you have bought has the extra (white) wire which you don't need - so it mustn't be connected to anything. It can, however, become live under some circumstances - so it needs to taped off safely.

Hopefully, armed with this information and with the diagrams in the Honeywell 'plan' document, you can work out what to connect to what. As far as the new valve is concerned, the function of each of the various wires is: Brown: Motor live - connects to output of zone thermostat Blue: Motor neutral - connects to a lot of other neutrals (some of which may be black if its old wiring) Green/Yellow: Earth - connects to a lot of other earths Grey: Permanent live feed to internal switch - connects to main heating system fused switch, and to the grey wire of the other actuator Orange: Output from internal switch - connects to boiler and pump, and to the orange wire of the other actuator White: Not used - cut off any bare wires, and insulate the end

HTH!