Wiring external programmer to CH boiler Help and information on all topics relating to your central heating, air conditioning and ventilation issues.

[jayzee]

Hi,

I have a Worcester Highflow rsf 400 which just has on the front on off switches for hot water and central heating.

I want to add an external programmer to the boiler and have found the following wiring diagram in the manual

[img]http://www.freebies.co.uk/rsf400.gif[/img]

I have bought a Drayton LP522 Programmer and the instructions have the following wiring diagram

[img]http://www.freebies.co.uk/lp522.gif[/img]


My problem is how do I wire it up, I have a live and neutral on both but the boiler only has a "switched wire" for CH and HW not an on off for each like the controller.

Do I need to wire the switched for each from the boiler to the on wire for each on the programmer?

boiler 3 -> 3 programmer
boiler 4 -> 4 programmer

Thanks for any input as I am keen to start saving some money on my heating by having a bit more control.

J

[plumbbob]

You don't say whether you want the new programmer to control both the hot water and the heating. It is not clear which of the two diagrams that appear on your photograph for the programmer refers to the switch you have bought. The first is a single channel on/off timer whereas the second is a two channel (hot water AND heating) controller.

The wiring is quite simple once this has been established.

[jayzee]

Thanks for the reply plumbbob

I DO want to control both hot water and central heating

when I bought the programmer although it is a central heating and hot water one, the instructions that actually came with it were for the lower model which is only single channel.

I found the proper manual on the web which is where the image I have posted comes from but this manual I think covers both the single and dual channel model which is why there are 2 diagrams.

but basically the programmer I have has the connections as per the second wiring diagram headed "wiring the programmer", the "wiring the time switch" diagram i think must be for single channel controllers.


If this is the case how do I wire my 4 wires from the boiler to the 6 connectors on the programmer.

thanks again for the help

J

[plumbbob]

Ok, so based on what you say, here goes.

Remove the link wire between pins 2,3 and 4 on the boiler connector block as shown on the diagram.


Join the neutral from the boiler to neutral on the timer.
Connect pin 2 (Live supply to programmer) to the live pin on the Drayton.
Link pin 3 (Switched Hot water) to pin 3 (HW) on the programmer.
Link pin 4 (Switched C/H) to pin 4 on the programmer.

Good luck and happy bill saving. Lol