combi boiler conversion

[alpha spark]

Hi been to look at a job today a client of mine wants http://m.diy.com/mt/www.diy.com/nav/fix/plumbing/plumbing-supplies/central_heating_pumps___controls/-specificproducttype-thermostats/Drayton-Digistat-and-3-Room-Thermostat-11598024?&action=detail&un_jtt_redirect#additional%20information one of those fitting on her combi boiler are they easy to do I have very little experience with central heating systems and is some thing I'm wanting to learn about At the moment there is a 5 core flex from the boiler to a surface box and blank plate a 2 core flex and a 3 core flex flex to a Randell 103 time clock also at this time clock is a 3 core flex from the spur and a 3 core and earth to the thermostat at the top of the stairs Ill be home soon so I'll put pics up but from my understanding all this can be ripped out upto the surface box I then supply the new commanding box and boiler with live neutral earth from the spur. Are the other 2 cores to the boiler a switching pair that will operate when the new wireless stat tells it to operate

 

[SLIPSHOD & SLAPDASH]

Bad link

 

[alpha spark]

Drayton Digistat and 3 Room Thermostat, 5016254105892

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i think that is the link now im gonna have a go at the pics

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http://i1167.photobucket.com/albums/q622/alphaspark1/006.jpg

wiring inside Randell 103 time clock

http://i1167.photobucket.com/albums/q622/alphaspark1/008.jpg

pic of randell 103 and spur

http://i1167.photobucket.com/albums/q622/alphaspark1/009-1.jpg

pic of boiler and 1g surface box with blank plate at bottom

http://i1167.photobucket.com/albums/q622/alphaspark1/007.jpg

wiring inside 1g surface box connections at bottom go to boiler 5 core flex

http://i1167.photobucket.com/albums/q622/alphaspark1/010.jpg

wiring diagram from boiler instructions manual

 

[Manator]

Alpha you will need to know the wiring plan for the boiler controls, this could be a Y plan, S plan or other or indeed a combination.At first the more wires the more complex it appears, but the basics never alter and a methodical approach to wiring gets you through OK.

 

[alpha spark]

https://www.youtube.com/embed/PjwnPvpWoUQ?feature=oembedvideo where i got my info from

Hi manator correct me if im wrong which I probably am hope the pics make more sense than me waffling on I thought as its a combo boiler it don't have a y s plan as there are no valves etc as its within the boiler

 

[Manator]

If it is not controlling any valves or motors then it should be pretty straight forward,I will look at the photo's and see if I can help, but I rarely get involved with boilers.

It looks like an easy job, you will need the wiring instructions for the new programmer/stat it will give you the comparative wiring connections for different models.

 

[alpha spark]

Thanks manator

I take it the black and grey are the switching pair that go on or off via the thermostat or timer and the others are self explanatory

 

[Manator]

Continuity check all cables and you can not go wrong, simple test to do and saves the embarrassment of doing it wrong, never assume was one of the things I was taught, because it makes an a** out of u and me.

 

[alpha spark]

I did a quick test while i was there the voltage between the black and earth was 230 v the grey between earth was 0v until I activated the time clock then it came live

True though lol

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Untitled Page

draytons wiring diagram

 

[Manator]

I did a quick test while i was there the voltage between the black and earth was 230 v the grey between earth was 0v until I activated the time clock then it came liveTrue though lol

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Untitled Page

draytons wiring diagram

re check the link, I can not access the file

 

[alpha spark]

http://i1167.photobucket.com/albums/q622/alphaspark1/011.jpg

try again

 

[steptoe]

alpha, generally for a combi boiler you need a T&E to the programmer, a 3c&e from the stat to prog, and a 5c from prog to boiler,

check to see if the boiler is voltfree or mains switched, that is usually the only difference, apart from external pumps requiring over-run [generally not on a combi].

do you have the wiring specs for the boiler?

 

[NozSpark]

Alpha,

I do loads of Worcester boiler wiring.

You need to take the cover off the boiler, two screws at the top and two captive ones underneath (in whitish plastic clear blocks), then you have a screw above the panel. Lower it down and then undo three screws holding on the grey cover.

The power and stat connections are on the far left hand green block (it unplugs vertically), if you are not using the Worcester (integrated) timeclock then you would connect a programmable one (contacts) between the L and LR terminals on the block and the supply to the timeclock from the same supply as the boiler.

 

[steptoe]

ah, its a worcester, you dont actually need Ls then, they are 230v switching,

CH from clock to stat, switched live from stat to Lr on boiler, simples.

 

[alpha spark]

http://i1167.photobucket.com/albums/q622/alphaspark1/012.jpg

this is how its wired at moment

http://i1167.photobucket.com/albums/q622/alphaspark1/013.jpg

this is how she wants it wiring

is this ok

 

[steptoe]

can your RF unit switch 230v ?

 

[NozSpark]

Alpha,

Ditch the joint box it's over complicating everything, just connect it in the back of the receiver box

 

[alpha spark]

Not sure steps I'll have to have a look

Thanks noz can this scr box go in the cupboard or does it want moving out of the cupboard do you fit these digi stats quite often ?

 

[steptoe]

I normally just fit the receiver beside the boiler, never had any problems so far.

 

[NozSpark]

If I have to fit a RF one I normally use the Salus ones and fit them right next to the boiler