Wiring a CM927 into a Worcester Bosch 240

[not so warm]

I have a well maintained WB240.
It currently has a sunvic select 207 digital timer etc.
Wired in as follows:
N= N blue
L= L brown
T1= blank (hw off)
T2= blank (ch off)
T3= black taped (hw on)
T4= black (ch on)

X10 panel on boiler wiring:
1=black (ch on)
2=black taped (hw on)
3= brown 230v L
4= blue N

I have purchased A Honeywell CM927.
From what I can see I will need to rip it the old timer and reattach the old switch on the front cover and set this to constant hw.

Wiring to do:

X10 term 1 to grey, leave disconnected as the cm927 will control this circuit or do I connect it and leave constant????.
.
X10 term 2 to white to control water either on or off.
X10 term 3 to brown 230v L

Now on the CM927
I would like to use the isolated switched live and neutral from the digi timer but it gets the power from the combi.
I could resite the RF unit closer to the boiler in the loft and then tap direct from the mains switch etc.

this is the plan.
N = neutral from mains
L1= live from isolated mains
L2= live jumped from L1.
A= boiler Terminal X4 pin 1.

B= boiler Terminal X4 pin?
This is where I'm stuck I'm left with X4 pins 2 or 3, I'm thinking 2.

Pinot for the thermostat on a 240 is

1. Live IN
2. CH ON
3. NEUTRAL


I'd rather ask a question

 

[D_Hailsham]

I suggest you retain the existing Sunvic timer to control HW. Just set the CH to permanently off.

As for the CM927:

L to X10/3
N to X4/3
A to L (link)
B to X4/2

Alternatively you can set CH permanently on at the Sunvic and connect L to X4/1.

What looks like a variable resistor is the anticipator, which is only found in mechanical stats.

 

[not so warm]

I must admit I prefer to keep the sunvic as it has been extremely reliable,
Just setting the Ch to off, great

So I'll link the two L's and then link A.

 

[not so warm]

Ok I've taken the live feed direct from the mains supply terminal below the terminals x10 as it was neater and closer.

Thanks guys it works a treat.

All in all I'm very impressed, I should've done it years ago, it as also recommended by the British gas engineer as well.
I short listed two this and the Siemens unit.

 

[Agile]

I suggest you retain the existing Sunvic timer to control HW.

Since this seems to be a combi there is no need to time useage of hot water on demand.

 

[D_Hailsham]

I suggest you retain the existing Sunvic timer to control HW.

Since this seems to be a combi there is no need to time useage of hot water on demand.

Makes one wonder why they show a combined CH/HW timer in the wiring diagram.