On Tue, 27 Sep 2005 10:18:22 +0100, in uk.d-i-y John Rumm
wrote:

TheScullster wrote:

I have tried major throttling of the downstairs rads to improve flow
upstairs, but do not seem to be able to get acceptable performance of
upstairs and downstairs rads to include items 6 and 7.

It does sound like a balancing problem (or perhaps lack of flow from the
pump in general - have you tried a faster pump speed (watch you don't
cause it to start pumping over)))

It may be you need to go back and rebalance the whole system from scratch.

Ahh... didn't notice you already suggested that.

So the question:

Looking at the pipe runs and radiator sizes involved upstairs, are 15mm
mains simply not up to the job?

15mm is good for upto 6kW of total rad output and you are going to be
nowhere near that...

That is the maximum heat load 15mm can carry, over some maximum given
length of flow + return. Lower loads can be carried further. Sorry I
don't have the actual lengths to hand.

Phil
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