"Alan Campbell" wrote in message
om...

Yes I do.

Basically, they back off the power as flow restriction increases, so
for example, if you have TRVs, the pump doesn't run its nuts off and
become noisy. It has a peak pressure point at just below 0.5 m^3/hr.
Above this it has a typical head/flow curve. Below it the power is
reduced as restriction increases.

I found that mine therefore runs a lot quieter than erstwhile models.

There are a few other features such as a deblocking function.

http://www.grundfos-www.com/alpha/frames_html.htm

Nice product and well worth having.


Would it work as well on a microbore system ?

My installation consists of 22mm (may be 28) pipe which does a circuit
under the 1st floor. From this, each rad has a tee down to microbore
(probably 10mm). Only a short distance for the upstairs rads and down
behind the plasterboard walls for the downstairs rads.

I guess there is more resistance in this setup than an 'ordinary'
setup.

It will work just as well on Microbore.