help central heating programmer

[brizospark]

Been called to a job where the client tried to change a central heating programmer.

He took the wires out the backplate and forgot to note down where they went! Monkey!

So I have the brown and blue from spur which go to L and N of the back plate but then I also have a brown and blue from boiler which go to either terminal 1,2,3,or 4 does anyone know off hand which terminals these should go to?

Programmer is a horstmann C17

 

[Guest123]

Is it a single or double channel programmer, could it be that the neutrals are linked and the brown is simply a switch wire. Or could it be that you have 2 switch wires, 1 for central heating & one for hot water.

Does the boiler have it's own supply also, is it a combi??

 

[brizospark]

Boiler has its own supply. 1 channel programmer. Am thinking that maybe the brown is common blue is sw/wire?

 

[brizospark]

not sure if the prog. has anything to do with the hot water think that just fires up when tap is open

 

[Guest123]

Sounds like you have a combi then.

You will have one switched line out on terminal 2 to the boiler for the CH. Is there a room stat present.

 

[brizospark]

lenny, it is indeed a combi and there is no room stat present

 

[brizospark]

so am i right in saying brown to common(2) blue to on(4)

 

[Guest123]

so am i right in saying brown to common(2) blue to on(4)

I would say so, yes.

 

[brizospark]

the guy is adamant that the brown flex went to nr. 1 but this was a lifestyle prog. not a horstmann, would this make a diff.?

thanks Lenny

 

[brizospark]

and also the blue should be sleeved brown?

 

[Guest123]

Page 2 of the PDF has a diagram.

Almost all programmers have terminal 4 as CH on, incuding the Drayton lifestyle ones.

There are 2 flexes at this programmer though aren't there??? Is he getting confused by this maybe???

 

[brizospark]

there is a flex coming from the spur. There are two flexes coming out of the boiler BUT only one connects to the programmer plate, the other can be seen behind the prog. plate just running through the metal back box of the prog. and going elsewhere???

 

[Geordie Spark]

there is a flex coming from the spur. There are two flexes coming out of the boiler BUT only one connects to the programmer plate, the other can be seen behind the prog. plate just running through the metal back box of the prog. and going elsewhere???

I suspect it goes to the roomstat - but you've said in an earlier post that there isn't one.

No matter though, as it isn't your problem.

 

[sparky3366]

might be a permanent supply to the boiler,

 

[ratpig]

One of the cores is a switch live from the boiler (which would go to terminal 1 on a drayton lifestyle single channel clock) and the other core is a switched live return to the boiler (which would be terminal 3). LNE connected from SFU will power the clock. Power up the boiler and the clock, remove cover of the clock and test between terminal 1 and the neutral and you should get 230v (if the boiler is 230v switching).