"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.

My installation, heating loop, conists of a two-floor teeoff
with, on each floor, the distribution pipes stepping down
to each rad. Every rad is fed by 10mm pipes but the distribution
pipe steps down at each stage; -

=22==22-10-15==15==15-10-10===10==
| |
|
Rad Rad Rad
| |
|
=22==22-10-15==15==15-10-10===10==

each floor has a minimum of copper although it uses
several sizes of piping. The design/installation was at
a time when copper prices were going through the roof
-and Belgian paratroopers were dropping onto the
coppermines in Zaire (or was it the Congo.?)


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

Alan

--

Brian