boiler programmer wiring

[jimmyjay82]

Hi All,

My father in law has done some decorating for me and in order to be perfect he removed my programmer and back plate from the wall. Problem is he didn't write down the wiring before taking it off!

I'm now left with a bunch of wires and no idea where most of them go. I have an old boiler and digital programmer with a separate room thermostat located in a different room.

I have six wires coming from the boiler in two separate cables. They both contain live,neutral and earth. I have a mains power supply[thru a 3a fuse] and also what I presume is the wire from the separate room thermostat which has a blue, red and yellow.

My programmer terminal has e,l,n then 123 are spare, 4 is off, 5 is com, 6 is on. any idea which wires go to which terminals?

The programmer is a randall 911 and the boiler is an old Worcester 9.24 before any one says I know I need to update them but money is tight for all of us!

any help much appreciated.

 

[D_Hailsham]

My father in law ... didn't write down the wiring before taking it off!

Sack him.

You have a job on your hand as you will have to trace every wire and see what it is connected to.

Do NOT make any assumptions, e,g Blue is neutral, Green/Yellow is earth.

I have six wires coming from the boiler in two separate cables. They both contain live,neutral and earth. I have a mains power supply[thru a 3a fuse]

Does the mains supply from the fuse come in where the back plate?

If so, one of the two cables will be the mains supply to the boiler (connects to L, N and earth in boiler). The other is probably the feed from the thermostat to boiler (connects to terminals 2, 3 and N1 in boiler).

You need to identify both these cables. If you have a multimeter it's easy.

I have assumed you have the 9.24 Electronic RSF. If that's incorrect, can you give me the exact model number or, better still, the GC number?

what I presume is the wire from the separate room thermostat which has a blue, red and yellow.

So this cable also comes back to the backplate?

Check at the stat which coloured wire connects to which terminal?

 

[jimmyjay82]

Thanks for your reply.

The digital programmer is separate to the boiler. this is where I have the confusion of wires. I Don't know which goes where in the separate wall mounted programmer.

I have an earlier version of the 9.24 which simply has a temperature and water, off or water and heating switch on the boiler hence the need for a separate programmer. Not sure which model will have a look.

I checked the thermostat and the red is live and blue + yellow are both neutral.

I think the two wires coming from the boiler to the programmer are one from the boiler and one from the pump but I might just be getting myself confused now!

I need to know where the wires coming from the boiler and the stat go into the programmer.

help is much appreciated.

 

[jimmyjay82]

p.s I can't sack him his retired and gets bored so he likes to do things around the house. When he runs out of things in his own house he starts on mine and is usually pretty good and comes in very useful for things I don't want to do!

 

[D_Hailsham]

The digital programmer is separate to the boiler. this is where I have the confusion of wires. I Don't know which goes where in the separate wall mounted programmer.

I realized the boiler and programmer were separate. That's why I said you need to identify both cables at the boiler end.

Do you have a multimeter or can you borrow one (father in law) and do you know how to use it? If so, here's how you identify one cable:

Turn power off
Join the blue and brown of one cable together at programmer end
Disconnect the blue and brown of one cable at boiler end. (Make a written note of connections)
Set meter to Resistance (Ohms - &#937 lowest range
Measure resistance between the disconnected blue and brown at boiler end.
If it's very low ( a few ohms) you know this is the cable you have joined at programmer end.
If it's high (often shown as a 1 - same as when the probes are not touching each other) you know this is the other cable.
Label both cables and make a written note of which terminals they are connected to at the boiler.

I hope that's clear.

I checked the thermostat and the red is live and blue + yellow are both neutral.

You won't have two from neutral. Can you say which stat and which terminal numbers each wire goes to?

I think the two wires coming from the boiler ... are one from the boiler and one from the pump.

Isn't the pump internal to the boiler? It is a combi boiler?

 

[jimmyjay82]

ok yes sorry confusing myself as I said. looked at that many manuals I'm going potty.

Traced wires and labelled. Inside boiler first cable goes to live ,earth and neutral other goes to terminals 2 and 3. [yellow/green wire seems to have disappeared on this one by time gets to boiler]

In thermostat red wire goes terminal 1, blue goes to 2 terminal and yellow to 3 terminal and its a Honeywell stat, again old and model number doesn't seem to appear anywhere on it.

Thanks