"Christian McArdle" wrote in message
...
If an extra pump is needed for a conservatory heater, then are there
small pumps available? The standard CH pumps seem too large to me.

A zone valve would be fine instead. You can
zone off with individual pumps
or with zone valves. Pump zoning also requires
one way valves which are hard
to find in a quiet configuration. I much prefer
valve zoning, particularly if the main pump is
a good one, such as a Grundfos Alpha.

I prefer pump zoning as valves restrict flow. Look insude a 22mm, and you
see a 15mm orifice. Pumps are more reliable too. If using a fancoil heater
you will need flow through it. 90% the existing CH pumps can't do it in a
retro fit, unless the fancoil is near to the boiler/pump and the pipes are
22mm most of the way. Conservatories at times are at the end of the CH
circuit with only 15mm conveniently available.

Small pumps? Grundfos make a small secondary circulation pump called the
Comfort for secondary circulation applications. I see no reason why it
can't be used on a CH loop, but check with Grundfos if you can get hold of
anyone with sense there. It comes in many variations, with integrated:
timer, stat and non-return valves. A basic unit with integrated non-return
valve may fit inside a fancoil units case (depends on units of course). It
can be switched on via the fancoil wall mounted thermostat or
programmer/stat and give extra flow to the fancoil unit. It is not cheap
around £100. There may be other makers making small pumps, but I haven't
seen them, perhaps others may know of one.

If cheaper smaller pumps were available, then a 3 zone setup: upstairs,
downstairs, DHW cyl, could have a small pump for each zone taking up little
space at all.