Batteries? I'm beginning to suspect that the gremlin that lives inside it
has died as it's not turning at-all now. Plus point is that central
heating
is on predictably now, however not so good as my wife keeps turning it
down
at night before coming to bed so she's not too warm. Unfortunately I'm
first
up in the morning and have to turn it up again.

I'd take a picture though I don't know which box the camera's in, and sods
law dictates that the cable to connect same to PC is in a box at the other
end of the house. I did find this however, which sort of indicates that
replacement could be a 'doddle'.

http://www.sunvic.co.uk/Select%20Pro...s/207ins_w.pdf

Am I correct that replacing this control unit would fall outside the
requirements to be done by a CORGI registered individual? Also, if anyone
could suggest an alternative unit (pref available in the UK via post...?).


It is a doddle. Most programmers now use the backplate shown on the link,
and all you have to do is wire the new one as given in the wiring diagram.
This is nothing to do with CORGI.
Adam