Set Square wrote on Sunday (22/02/2004) :
I am considering overhauling and zoning my central heating later this year,
and would like separate control of each rad. I'm looking for motorised
valves which are as small as possible and which will fit on 15mm pipes. The
only ones I can find are 22mm. [Yes, I know I can use reducers - but the
whole thing is still too big].

Solenoid valve are available which are quite small, the problem might
be the noise they make as they energise and de-energise. They are
though much more reliable than motorised valves.

--

Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.org