Do I run a long length of flex all the way from the cylinder upstairs to the boiler, pump, and valves, downstairs or should I run a short length of flex from the cylinder thermostat to a junction box in the airing cupboard and then use twin and earth for the long run to the boiler? Or doesn't it really matter? Do you use whatever is to hand?
On the subject of using whatever is to hand, I am also replacing the old clockwork time switch with a digital programmer. I know I can buy multicore wire to connect to this but if I have 2 or 3 core cable already, can I just use a few lengths of these?
I have something in the garage. I cant remember if it is 2 or 3 core. If it is 3 core, can I use this for the thermostat and just snip off the earth or is that considered bad practice? Should earths always be connected to something?
If it is 2 core, is it alright to use that to run from the wiring centre to the programmer since the programmer does not need an earth? Or is it good practice to always have an earth (there is a brass terminal in the back plate to connect one to if required).