Want to Wireless on a Worcester 24CDi RSF

[Adie1]

Hi

HELP!

OK, back to being sensible, First of all I am an engineer but have very little knowledge of electrics or Central heating wiring so please bear with me.

I have a Worcester 24 CDi RSF boiler that has the Worcester digital timer clock/programmer in the front fascia, I believe the part no for this is 77161920030. If I understand correctly to provide temp control to this I have an external thermostat wired into what is know as 'ST8' on the boilers connections. This basic setup works well with the exception that my thermostat is right by my front door and the temp control is very poor over the system as a result. I would like to move the thermostat into my living room at a very minimum but a change to a 7 day programmer would be great. Obviously this will now have to go wireless because of wiring problems.

OK I thought this would be a simple job to just purchase any Wireless thermostat/programmer and wire this into the 'ST8' connection on my boiler and just switch the old worcester contoller over to contiuous mode for the new controller to take control...with me so far?

Now, this where I fall over... the wiring. The ST8 wiring connection has four terminals.... Ns..Ls..Lr..Spare. According to the Worcester instructions the thermostat I have connected should be (but I have not checked yet)..Ns= neutral, Ls=Live, Lr=Switched live, Spare=nothing in it.

The wireless thermostat I am considering is the Honeywell Y6630D Room Thermostat. Now the wiring for this thermostat shown in the instructions here http://www.screwfix.com/prods/84067/Plumbing/Central-Heating-Controls/Honeywell-Y6630D-Room- for a combi boiler shows 4 connections to wire it in when I only appear to have 3 on my boilers ST8 connector. The 7 day programmer I would really like is the Honeywell CMT927 Wireless 7 Day Programmable Room Thermostat. This again shows virtually identical wiring to the Honeywell stand-alone thermostat aswell.

What I am looking for is a bit of an idiots guide to how I can wire either of the new thermostat/programmers in and if I go for the 7 day programmer whether I have to remove the original Worcester item from the fascia or not.

Sorry for the long post and not being very electrically 'Bright' but it can't really be that hard can it? I will try to post some pics of the wiring DWG's of the various bits later if necessary.

Can anybody help?

Thanks in advance for any advice offered.

 

[Adie1]

Hmm... am I asking too much?

A

 

[bengasman]

Remove old clock and stat.
buy honeywell cm 917 ( can never remember the exact model, but it is 7 day model) or siemens rev24rf and connect if you are competent or get someone to do it for you if you are not sure.

 

[Joe4542]

Hi,
First unless you get a compatible replacement thermostat (poss unlikely) you will want to remove the current one from fascia and replace with the blanking plate (which you prob wont have...)

The only terminals out of the three you need to care about if fitting new Digi Programmable roomstat etc, would be the LS (Live Supply) + LR (Live Return). These two need to be connected to the new items' switching terminals - When these two are linked the boiler fires up (demand).

The other wires the Digi Stat would need are a Live + Neutral (poss earth but since most controllers are plastic and 'double insulated', its generally not req'd).
These you can get by either piggy-backing onto the boilers input L+N terminals or alternatlively up into the junctions box/Fusd spur fo boiler.

Hope that helps
Joe

 

[h4gg13]

You could always do the easiest option and get a WB digi stat and receiver.
Receiver is fitted where your digital timer is at the moment,just plugs onto PCB.

 

[Adie1]

You could always do the easiest option and get a WB digi stat and receiver.
Receiver is fitted where your digital timer is at the moment,just plugs onto PCB.

Apparently availability of the genuine digistat is thin, function is poor and very expensive. Cost is not that material but there are much better units with better functions for less than the WB Digistat. Maybe it is my ignorance but I thought that any wireless controller could be fitted to pretty much any boiler.
Cheers
A

 

[Joe4542]

The new Worcester Programmable Roomstat RF (DT10RF MK2) should be available easily from local merchants, but other wireless stats would be even easier to find - and much cheaper.

The worcester one appears to be a drayton Digistat+ 2 RF, but obviously with a modified receiver to plug directly into the boilers faceplate socket.
I don't know of any problems re range/ability of these, all the ones we've fitted have worked fine...

Yes you shoud be able to fit pretty much any modern Digital type stat - they should only need 4 (or 5) wires for the receiver (mounted by boiler) and then the user part (transmitter) wherever you want (within reason + logic) powered by a couple of AA's.

Joe

 

[mikej2005]

The new Worcester Programmable Roomstat RF (DT10RF MK2) should be available easily from local merchants.. ..the worcester one appears to be a drayton Digistat+ 2 RF, but obviously with a modified receiver to plug directly into the boilers faceplate socket.
I don't know of any problems re range/ability of these, all the ones we've fitted have worked fine...

I've got the DT10RF (mk1) on my WB 37CDi combi and it was 'plug and play', so very easy to fit.

I haven't found the range to be that great though - I originally tried locating the controller in the dining room but it kept losing contact with the receiver on the boiler, so the signal doesn't seem to be strong enough to pass through an external cavity brick wall and internal (single) brick wall. I've since moved it into the kitchen, where it works fine through the cavity wall only - hardly the best room for a thermostat though !

 

[Joe4542]

I've taken this excerpt from the instructions for the Mk2 digistat.

Radio signal range
The range may be affected by the composition / density and
number of walls between the Digistat RF and receiver.
30 metres typically, through two internal plasterboard walls and
a ceiling.
26 metres typically, through three internal plasterboard walls
and a ceiling.
17 metres typically, through two internal plasterboard walls a
ceiling and one external cavity wall.
These distances are provided for guidance only, many factors
can affect the range of the transmitter, including metal
pipework, appliances and even furniture

 

[mikej2005]

17 metres typically, through two internal plasterboard walls a ceiling and one external cavity wall.

My total distance was about 11m through one external cavity and one internal brick wall - it's obviously the brick walls that kill the signal quite severely.

 

[Adie1]

Hi Joe

Is this new version DT10RF MK2 a straight plug-n-play with my old 24CDi RSF? I have not seen a listing for my boiler in any details on it.

Cheers

A

The new Worcester Programmable Roomstat RF (DT10RF MK2) should be available easily from local merchants, but other wireless stats would be even easier to find - and much cheaper.

The worcester one appears to be a drayton Digistat+ 2 RF, but obviously with a modified receiver to plug directly into the boilers faceplate socket.
I don't know of any problems re range/ability of these, all the ones we've fitted have worked fine...

Yes you shoud be able to fit pretty much any modern Digital type stat - they should only need 4 (or 5) wires for the receiver (mounted by boiler) and then the user part (transmitter) wherever you want (within reason + logic) powered by a couple of AA's.

Joe

 

[Joe4542]

Actually doubt the mk2 would work on yours - worcester prob changed something (deliberatley) so it wont.

Best bet would be to check with Worcester technical though!

Sorry!
Looks like normal Wireless stat programmer is gonna be your best bet.

Joe