"Christian McArdle" wrote in message
t...

Having by-pass valves with condensing
boilers is not recommended and
should be avoided. These raise the return
temperature reducing efficiency. Try
Grundfoss Alpha pumps.

Of course, many condensing boilers have
internal pumps, so this advice can't
be followed.

It can be I said "Having by-pass valves with condensing boilers is not
recommended and should be avoided". Sound advice. There are many ways to
get around this. A heat bank/thermal store. Replace the internal pump with
a Grundfos Alpha. Install an intermediate buffer store - a 40 litre cylinder
heated by the boiler, with a fixed speed pump between boiler and pump and
Grundfoss Alpha between the rads and buffer cylinder, etc, etc.

The DIYers know all the answers don't they.



_________________________________________
Usenet Zone Free Binaries Usenet Server
More than 120,000 groups
Unlimited download
http://www.usenetzone.com to open account