In article ,
John Laird wrote:
Please go through the balancing procedure described in the FAQ.

To be fair, I think the OP has made some steps in that direction. Where
he probably needs help is in judging the amount to open up the LSVs on
the lower radiators so as not to starve the upper-floor units of heat.
I spent some time re-balancing my system a couple of years ago, and was
quite surprised that some radiator valves literally only need to be open
half a turn (maybe even less), while others needed to be fully open.

It's some time since I've read the FAQ, but isn't this covered in that?
Gate valves tend to be very non linear, as opposed to 'tap' types.

I didn't use a thermometer, it has to be said.

It makes life so much easier. And accurate DVMs that incorporate a
temperature probe are cheap these days - and will find more uses than a
pipe thermometer.

All my radiators have TRVs
and I wasn't entirely convinced that you can follow a rigid approach
with one valve when at the other end of the radiator there is another
working all by itself (and in general they are almost never fully open
or closed but constantly adjusting, especially during times when the
water is heating up). Even now, some radiators take a little longer
than others to warm up, but once the system is fully heated, they are
heating about as evenly as I would want.

I didn't believe just how important taking time to balance the system
properly was - thinking you could just rely on the TRVs. But if you want
the house to warm up evenly, it's vital.

With the vast majority of the OP's radiators on the ground floor, these
are the ones that will, in the main, need to be virtually closed off.

Yes.

He does have quite a large load but the boiler is spec'd at 24kW and
ought to be able to cope. Likewise, one would hope the boiler designers
fitted a suitable size pump integral pump.

But you need to key down the flow to the rads that are the offenders
before worrying about the pump. I've also got a three story house, and my
pump is set on minimum (out of three settings).

--
*Growing old is inevitable, growing up is optional *

Dave Plowman London SW
To e-mail, change noise into sound.