On 6 Oct 2004 04:14:24 -0700, (Simon Langford)
wrote:

I'm having difficulting getting the radiators on the 2nd floor of our
house to heat up. My efforts have so far involved closing down the
LSVs almost completely on the hottest rads (kitchen area and ground
floor), leaving the LSVs wide open on the 2nd floor, and somewhere in
between on the 1st floor.

Have you actually followed the detailed procedure, or is the above all
you have done?

On balancing radiators, the FAQ says...

"The important thing is that the return water coming out of each
radiator is good and hot. If it's only warm you need to open its Lock
Shield Valve (LSV) some more, or if it's already wide open you have to
close the LSVs on the hottest radiators instead."

True, but it then gives detailed instructions on what to do.

The problem is that the 2nd floor rads are still not hot (just warm),
and the ground and 1st floor rads now have cool return pipes. If I
open up the LSVs so get hot return pipes on the ground floor, then the
2nd floor rads are even less hot.

Do you think I need a bigger boiler (it's already a pretty big one)?
Or would a faster pump help?

If you *have* followed the FAQ procedure, it seems that there is some
inadequacy in the plumbing design. To track this down, try the
following:

Turn off the boiler.
Open both valves fully on one radiator and close down all the others.
Turn boiler back on.

If that radiator heats up, repeat for each of the others in turn.

If you find one or more that won't heat, then either

the pipe run is too long for the bore used,

or the pump is not producing enough pressure (too small, broken, set too
slow),

or there is a blockage in the rad or pipework (sludge or airlock).

or a combination of these.

The boiler size would only be a problem if it is firing continuously
flat out and the radiators are still not getting all equally hot.

If that does not help you will need to give us much more details of the
system and what it is doing.

Phil
The uk.d-i-y FAQ is at http://www.diyfaq.org.uk/
Remove NOSPAM from address to email me