Replacing a Central Heating Timer -arrggghh

[dstaton]

HELP - i'm losing the will to live...

I am trying to replace my central heating and hot water timer. The existing unit is a Randall 103, and I am trying to replace this with a Siemens RWB2. It should be same (or so i thought), as there are 9 wires. These consist of a live, neutral and earth for the feed, HW and CH. I have established which do which but cannot get the blooming thing to work! (I can e-mail diagrams if required - they won't paste in)

The new unit has the following connections:

N (Mains - fused)
L

1 - HW Off
2 - CH Off
3 - HW On
4 - CH On
Earth

Whilst the old unit had a bridge for the live, I assume this is not required for the new unit. Or, is this where I am going wrong?

Please help

 

[WDIK]

http://www.heatingcontrolsonline.co.uk/instructions/rwb2.pdf

 

[dstaton]

Thanks for the manual - although I do have this already.

Still can't seem to fathom it?

 

[namsag]

Do you have a gravity system or a fully pumped sytem ,you say
You have a LNE to clock
CH supply
HW SUPPLY
That is 5 wires are your missin 4 wires 2 neutrals and 2 earths for ch/hw supply And don`t just go by colours did they come out of neutral and earth terminals

 

[dstaton]

Thanks the prompt relpy. I have a gravity HW system and pumped Ch system.

Apologies - I should have clarified the wiring. I have Live, Neutral and earth colurs for each (CH, HW and to Clock) - 9 wires (three of each). I have tested them all and have established the feed live, and contained within that cover / schroud is also a bule and a green / yellow, which I assume to be the neutral and the earth.

It is a fairy modern house (1988) hence, I am of the understanding that the wiring hasn'e been tanpered with, and the colours are in order (possibly a foolish view).

Any suggestions, or further tests that are needed?

Thanks

 

[namsag]

house built in 88 seems bit late to have a gravity system but providing it is this is what you should do and if possible following wiring/
From fused spur LNE to clock back plate . HW live outlet (3 on) back should go straight to boiler live terminal with N E connected into terminals of back plate.
The CH outlet 4 should go to pump via any room stat.
The programmer should be set on back to 10 programme (gravity)instead of 16 (fully pumped). instuctions will tell you how.

BUT what i while say on CH wiring colours dont always match to LNE which is why it is better if you can follow the wiring to where it goes

NO LIVE links required

 

[dstaton]

Thnaks very much - i'll give it a try. Incedentally, I think you are correct in saying that the colours don't match, as I think I have already tried your suggestion. I'll stick to ghetting the CH working and then replicate this for the HW.