Recommend cable type for Horstmann Programmer

joebre

Central heating is presently controlled by an APT mechanical time clock with stats on 3 zones plus hot water.

I want separate time and temperature control and am looking at a Horstmann Digital Programmer http://www.uk-plumbing.com/brochure/horstmann/ChannelPlusH47XLDatasheet.pdf

I intend pulling the new cables from the Programmer myself. I am not able to work out the wiring diagram on the link above.
Can somebody please advise what size and type of cable I would need.

Many thanks

Joe

davelerave

you need a supply and 4 channels anyway .theres a multicolored yy that might suit or a t+e and 2 twin browns even .

fishdog

I am not able to work out the wiring diagram on the link above.

I did a drawing for this in the sticky above (circuit drawings). I would like to think that it is clearer than the one you posted. Take a look and read wwhat I have said below.

1.5 cables are large enough for everything because the current drawn is only small (< 3 amps).
Note: earth cables are not shown in my drawing.

1) From the zone valves in the hotpress to the boiler a 4 x 1.5mm sq. cable.

2) From the time clock to each stat a 1.5mm sq. brown with earth. I use digital stats that do not require a neutral. They take a AA battery that lasts for years.

3) From each stat to its corrisponding zone valve a 1.5mm sq. brown with earth.

4) From the spur outlet to the time clock a 1.5 T+E.

5) From the time clock to the zone valves a 1.5 T+E.

Install a 4 x 6" plastic junction box in the hotpress to join all of the cables to the zone valves. The zone valves generally com with a flex connected to them. Bring all of the cables in through the back of the box and exit to the zone valves with 20mm stuffing glands to make the job look good! Be aware of cable routing. It is now a regulation that all cables in a hotpress are installed so that clothes can not be put on them like a "washing line".

From the isolator at the boiler to the boiler it is a regulation to use a heat resistant flex. A fan isolator can be used as the 3 pole isolator at the boiler.

Good luck!

joebre

Thanks fishdog for your reply.

I had seen your post in the sticky but I posted the pdf as it was specific to the programmer I was buying.

My situation is slightly different to your scenario.
3 storey house. Stat on each floor plus clyinder stat. Solenoid valves are located on each floor, near each stat, rather than in hot press.

I have a mechanical time clock on ground floor. I thought that I would have to pull 4 core cable to each of the 4 stats. However, I opened the clock today and I found 4 brown wires which I think go to each stat. I now think that I will be able to replace the existing clock with the programmer, without having to pull any more cable. ?

davelerave

joebre wrote: »

Thanks fishdog for your reply.

I had seen your post in the sticky but I posted the pdf as it was specific to the programmer I was buying.

My situation is slightly different to your scenario.
3 storey house. Stat on each floor plus clyinder stat. Solenoid valves are located on each floor, near each stat, rather than in hot press.

I have a mechanical time clock on ground floor. I thought that I would have to pull 4 core cable to each of the 4 stats. However, I opened the clock today and I found 4 brown wires which I think go to each stat. I now think that I will be able to replace the existing clock with the programmer, without having to pull any more cable. ?

i think you might be lucky .theres prob a wire going to each stat.hopefully the boiler is swiched by the mvs and not the timeclock.check if the mvs are 3-wire or five-wire first if you can .

edward543350

get a seven core licy cable and run it from the time clock to the hot press jb and then run another cable from the hotpress to the boiler which should be 4 x 1.5 nym/T+E the extra core is for frost stat.the licy cable comes with numbers on them as well so it easy to use;)