"Tim Lamb" wrote in message
...
In message , Doctor Drivel
writes

A good pump should last 10 years minium if fitted properly. Cheap pumps
dop't last.

Huh! These are Grundfoss and far from cheap.

Sounds like they are not fitted right.

Hmm.. This is a fairly big system; 21 radiators all fitted with TRV's
except two on bypass. The pump becomes noisy as the system reaches
temperature, particularly on overrun and hence the change to the adaptive
type.

A Smart pump is the way, but it seems the pump would have been better on the
cool return and with adequate flow, which it appears it was not getting. I
have seen pumps that are well installed last 20 years and more. Also
cycling does not help at all. Pumps running as cool possible, no cycling
and without stress just last. The boiler pumps on heat bank when on the
return do not cycle, when anti-cycle stats are installed, and just last.

Look at the Navitron web site and forum. They have many there who use
solar panels and solid fuel with heat banks.
http://www.navitron.org.uk/forum/index.php

They are pretty negative about wood burning boilers:-(

They do talk about how they are connected.

What is not understandable about a heat bank?

Pass.

They are simple and highly effective.