In article ,
Paul Roman writes:
I notice from the central heating diagrams that 4 (and sometimes 5)
connections need to be made between the junction box and the programmer.
Is there a particular cable for this or is it usually knocked up with a
couple of runs of twin and earth?

IME, it's usually done with a couple of runs of twin or triple and
earth. I needed 7 core for mine, and after a long hunt, I found a
small electronics shop in Luton which sold 7 core suitable for
mains use (H05RR-F7, IIRC) by the metre. Recently went back to get
some more and they've closed down - bugger.

--
Andrew Gabriel