Zone control or other option???

[TheOriginalTableLeg]

D_Hailsham,

The diagram you posted earlier (S plan plus with CM900), can you please clarify the following wire colours not labeled?

The wire that goes from Terminal 1 to contact A on the CM900,
The wire that goes from Contact B on the CM900 to Terminal 7.

The wire that goes from Terminal 6 to contact 1 on the cylinder stat,
The wire that goes from the Common contact on the cylinder stat to Terminal 8.

Time controller HW wire to Terminal 6,
Time controller HTG wire to Terminal 4.

I do not want to assume the colours.

Many thanks.

 

[D_Hailsham]

Unfortunately there are no "rules" when it comes to wiring heating controls, every installer has his own way of doing things - some even use the green/yellow earth wire to carry 230v rather than buy a proper multi-core cable.

Most of th wires you list are already in place, so what you have to do is identify them. That's easy!

If you remove the ST6400 from the wall (undo 2 screws underneath and the hinge upwards) you will see the connection block. The connections are as follows:

L - Live supply
N - Neutral
1 - HW OFF
2 - CH OFF
3 - HW ON
4 - CH ON

Your existing mid-position valve requires a wire to terminal 1 (HW OFF), but this is not required for a zone valve. So you should disconnect it and make safe at both ends (Other end connects to mid-position valve grey wire.)

You will also find that there are three wires connected to the HW cylinder thermostat. This is also because you have a mid position valve. One wire is not required with a zone valve. You can easily identify it: it connects to the GREY wire of the mid position valve. Disconnect this wire at both ends and make safe.

There are now two wires left on the cylinder stat:

One connects back to the timer HW ON (you should be able to identify this by the colour of the wire from timer HW OFF). These are the wires for terminal 6.

The other wire will connect to the same terminal as the orange mid-position valve wire. This is the wire which will connect to terminal 8.

(The above actually reverses connections C and 1 of the cylinder stat, but that is not important.)

This just leave the wires to terminals A and B of the CM907. I would suggest: Brown for Terminal A and Blue (with red sleeving or insulation tape wrapped round each end) for terminal B. The red sleeve/tape shows that is is a switched live.

 

[TheOriginalTableLeg]

D_Hailsham,

Many many thanks once again for your excellent reponses

The drawing you attached (S plan plus) I had seen in a couple of places on the internet.

I noticed that it appears to have been enlarged from a smaller copy and therefore has lost some of its clarity.
I have taken the time to reproduce it in colour and hope you will be able to use it for any future questions by anybody who may be asking similar questions to what I have asked.
Of course you may prefer the black and white version. Either way I hope it is of use to you or anybody else.

View media item 30388

 

[TheOriginalTableLeg]

D_Hailsham,

Can you please clarify my understanding of the following:

I have been looking at the CM927 as opposed to the CM907.

I like the simplicity of the wireless setup. If I understand it correctly, the transmitter is wired to the Zone valve for which it controls.

Ref: S Plan Plus wiring
A live feed from terminal 1 at the junction box to contact A on transmitter,
Contact B from transmitter is then connected to Terminal 7 on junction box (for 2nd room room stat and zone 2),
Terminal 7 is then connected to the valve motor which closes and makes the contacts Live from Terminal 1 on junction box through the valve motor contacts to Terminal 10 which in turn starts the boiler and CH pump running.

Plus, what if I wanted to replace the current DT200 room stat also with a CM927?

This would connect via Terminal 1 as well (live feed to pin A),
Then B would be connected to pin 5 on junction box, with 5 then connecting to 2 port valve for zone 1.

I guess I would have to leave the programmer I already have just for the hot water, then the 2x CM927's could be used to control each zone valve independently?

Like this?
View media item 30390

 

[D_Hailsham]

I have been looking at the CM927 as opposed to the CM907.

I like the simplicity of the wireless setup. If I understand it correctly, the transmitter is wired to the Zone valve for which it controls.

No, it's the receiver which is wired to the zone valve. The transmitter is the user control, which is battery operated.

Your wiring diagram is correct for the wired versions of the CM900 series, but not for the wireless. This is because the wireless version needs a permanent supply (Live and Neutral) to power the receiver.

So you run Live and Neutral from terminals 1 and 2 to the L and N terminals of the receiver; Insert a link from L to A; then connect B as shown.

The coloured diagrams are very helpful. Did you find them on the net or did you colour them in yourself? If so which program did you use? My original is taken from the Honeywell Wiring Guide.

One word of warning. The signal strength of the transmitter diminishes if it has to travel through several walls, so you need to check that it is OK before fixing the transmitter and receiver in place.

 

[TheOriginalTableLeg]

No, it's the receiver which is wired to the zone valve. The transmitter is the user control, which is battery operated.

Sorry that was completely my mistake, I did indeed mean the receiver and not the transmitter

Your wiring diagram is correct for the wired versions of the CM900 series, but not for the wireless. This is because the wireless version needs a permanent supply (Live and Neutral) to power the receiver.

So you run Live and Neutral from terminals 1 and 2 to the L and N terminals of the receiver; Insert a link from L to A; then connect B as shown.

I see .

The coloured diagrams are very helpful. Did you find them on the net or did you colour them in yourself? If so which program did you use? My original is taken from the Honeywell Wiring Guide.

I took the drawing you attached and drew a new version of it using Photoshop.

One word of warning. The signal strength of the transmitter diminishes if it has to travel through several walls, so you need to check that it is OK before fixing the transmitter and receiver in place.

Thanks again. The one for the living room would be be on the other side of the wall.
The hallway one (to the bedrooms) would be separated by only the door to the airing cupboard. But as you say I will check this on setting up.

I am currently drawing each individual component and its wiring in the hope you will cast you eye over it for me and clarify each connection is correct.

Many thanks again for your time and in depth responses.

 

[TheOriginalTableLeg]

D_Hailsham,

Do these look correct?

View media item 30394View media item 30395View media item 30396View media item 30397View media item 30398View media item 30400View media item 30401View media item 30402View media item 30403

 

[D_Hailsham]

Do these look correct?

Boiler

Your boiler has two "Live" connections: a permanent live and a switched live. See Fig 07 on Page 20 of the Boiler Manual

The wire shown in you diagram going from terminal 10 to the boiler is the switched live.

The complete system should be fed from a single connection to the house electrics. This can be done in two ways: connect the supply to the terminal block and connect the boiler permanent live to terminal 1; or, connect the supply to the boiler and feed terminal 1 form the permanent live terminal in the boiler. Whichever way it's done you will have four wires between the boiler and the terminal block.

Zone 1 Programmer Correct

Zone 2 Programmer Correct

Cylinder Stat Correct . However, I would swap the stat terminals (not the wires). So C and 6 are connected (Brown) and 1 and 8 are connected (blue/red). It's illogical the way that Honeywell draw it.

HW Programmer Correct

Pump Correct

Zone 1 Valve Correct

Zone 2 Valve Correct

HW Zone Valve Correct

 

[TheOriginalTableLeg]

Boiler

Your boiler has two "Live" connections: a permanent live and a switched live. See Fig 07 on Page 20 of the Boiler Manual

The wire shown in you diagram going from terminal 10 to the boiler is the switched live.

The complete system should be fed from a single connection to the house electrics. This can be done in two ways: connect the supply to the terminal block and connect the boiler permanent live to terminal 1; or, connect the supply to the boiler and feed terminal 1 form the permanent live terminal in the boiler. Whichever way it's done you will have four wires between the boiler and the terminal block.

Looking at my existing wiring, the boiler connection to the junction box is 3 core and earth (Brown,Grey,Black and Earth).
The Brown is connected to terminal 8.
Black goes to terminal 1 and is marked with red switch wire cover.
Grey goes to Neutral terminal 2 earth goes to terminal 3.

The mains in is Live to pin 1, Neutral to pin 2 and earth to pin 3.

Cylinder Stat Correct . However, I would swap the stat terminals (not the wires). So C and 6 are connected (Brown) and 1 and 8 are connected (blue/red). It's illogical the way that Honeywell draw it.

I seem to remember reading you said that on another post. Thanks for that.

Many thanks once again

 

[TheOriginalTableLeg]

Is this now correct?

View media item 30431

 

[TheOriginalTableLeg]

Please feel free to use any of my pictures if they are of any use to you for any future posting.

 

[D_Hailsham]

Is this now correct?

View media item 30431

No! Read what I said:

However, I would swap the stat terminals (not the wires). So C and 6 are connected (Brown) and 1 and 8 are connected (blue/red). It's illogical the way that Honeywell draw it.

In other words leave the wires connected to the terminal strip exactly as in your first pic. Just swap them at the stat end.

 

[D_Hailsham]

Looking at my existing wiring, the boiler connection to the junction box is 3 core and earth (Brown,Grey,Black and Earth).

Strange colour combination!

The Brown is connected to terminal 8.

From boiler switched live? If so this will move to terminal 10

Black goes to terminal 1 and is marked with red switch wire cover.
Grey goes to Neutral terminal 2
Earth goes to terminal 3.

Presumably from the L, N and E terminals of the boiler

The mains in is Live to pin 1, Neutral to pin 2 and earth to pin 3.

Is this at the boiler end?

 

[TheOriginalTableLeg]

Here's my junction box.

View media item 30438
The 3 core and earth is the harmonized colours.

 

[D_Hailsham]

The 3 core and earth is the harmonized colours.

Since when?

PS Pretty pic!