"Set Square" wrote in message
...
If your pump
is running flat out, but is still not enough, I'd be tempted to install
another one very close to the existing one but in the other pipe - so that
one is in the flow and the other in the return. [Make sure they're the
right
way way round so as not to fight each other!] Connect them together
electrically so that they both go on and off at the same time. In effect,
one will be circulating water between the house and the boiler and the
other
will be circulating it round the radiators - but they will just be working
in series, so there's no need for any additional by-pass circuits.

Thanks - that's even easier to do.


[I hope that the long pipes between the house and out-house are well
lagged!]

In the process of doing so. This farm building had the original warm roof
concept - hot water pipes right under the tiles.