Honeywell Sundial wiring centre

[TheOldFellow]

I'm about to wire up an extra CH zone, the thermostat will call the valve, and the valve's auxiliary switch will call the heating system.

However I find that the system is wired using an Honeywell 42005748-001 wiring centre. This appears to have no provision for a second (third etc) zone.

anyone know how to wire the zone into such a wiring centre? This photo shows how it is currently wired:

I just connect it to the roomstat terminals in parallel with the existing roomstat this will also call the main S plan zone valve.

If this is too complicated, I may just replace the wiring centre with a

10-way junction strip. I'll want to add more zones as I go through the renovations.

I was planning to place the new zone valve in parallel with the existing CH zone valve, so either one or both could be open. So the new one would be tee-ed in at the same point that the DHW feed leaves the pumped feed from the boiler. Bottom of is photo, near the broomstick top:

zone return just joins the main return wherever convenient.

I hope that's right?

Thanks, R.

[ARWadsworth]

If you are not adding an extra programmer and are just zoning the heating using room stats then wire up the new 2 port valve and the new room stat in parallel with the existing CH 2 port valve and roomstat with just one small alteration.

The alteration is. The return/call from the new room stat should be connected to the BROWN wire on the new 2 port valve and these two wires should not be connected to anything else. A piece of strip connector should be fine for this connection

Adam

Adam

[TheOldFellow]

The new room stat is a programmable, two wire. I take your term Programmer to mean Programmable Time Switch, a Honeywell ST699 in my case. So to check by paraphrase:

Connect the Grey (Switch 1 - live), Blue (Neutral), G/Yellow (Earth), Orange (Switch 2 - Boiler/Pump call) of the new zone valve into the same connectors as the Current zone valve. Connect the new stat between live and the new Zone Valve Brown (Motor Live).

Yes, I understand that and see how it works. Thanks, saved me from rewiring the lot although I might just do it anyway, as I find the wiring much easier to understand when I can see it all!

[TheOldFellow]

Correction: where I said the new stat should be between live and valve-BROWN, I meant the ON-HW terminal of the Programmer and valve-BROWN.

Otherwise the zone can call the boiler even when the timer is off.

R.

[ARWadsworth]

As long as you connect the new programmable stat to a permanent live (the grey wire from the 2 port valve is fine) and then put its return only to the brown cable in the new 2 port valve you will have two independant CH zones.

Do not wire the new stat up to the old stat as I first suggested as the new zone will only work when the "old" zone is calling for heat via the old 699 programmer.

HTH

Adam

[ARWadsworth]

Do you want to have two separate time controlled CH zones or two CH zones that are controlled by one master time control programmer and then uses two stats (one a programmable one) for each of the zones?

Adam

[TheOldFellow]

I really don't need the 699 for the CH, I use the time-switch for the HW so that it gives the boiler a long run rather than topping up the cylinder (OSO unvented) temp.

I see why you ask the question, if the new zone is to be completely independent of the other zones, then the time-switching should be part of the zone controls. If we want a whole-house time-switch then the Stat should be fed from the common time-switch.

In fact I'm going to use a Programmable Stat (Hostmann Centaurstat), so I don't really need the 699 in the feed.

As you say in the other thread on wring diagrams (good thread BTW) there are a lot of ways that a fully zoned system can be done. And this is why I may trash the Sundial Wiring Centre and put in a big choc-block!

Thanks for the inputs. I feel quite confident about it now I've got the logic of the thing worked out.

R.

[ARWadsworth]

I have sent you some info if your email iscorrect

Is it is not correct and you want the info email me.

Adam