quick rad balancing question

[sparkybird]

Thanks to advice on this forum, I'm in the process. My question is, once the first rad has been balanced and I move on, should the temp difference stay the same on it (ie between flow and return) or might it vary as I adjust the rest of the rads?

Also how long should I wait to ensure that the temp difference is stabilised and I move on to the next one?

I also noticed that on some of the older rads, when I opened the lock shield valve fully there was a little water escape - is this normal? Should I get them replaced with new?

Thanks in advance!

SB

 

[D_Hailsham]

once the first rad has been balanced and I move on, should the temp difference stay the same on it (ie between flow and return) or might it vary as I adjust the rest of the rads?

Yes the temp diff will change. Go round all rads in turn, then go back and start again. You may have to do this several times, but don't expect perfection.

how long should I wait to ensure that the temp difference is stabilised?

About 5 -10 minutes

when I opened the lock shield valve fully there was a little water escape - is this normal?

You shouldn't need to open the valve fully, but there's no harm in changing them. You can also try tightening the nut round the spindle

Start balancing with all LS valves a third of a turn open from closed and make very small adjustments.

 

[sparkybird]

Many thanks - that's very helpful - I can see it's going to be a long night!

The problem I have is that the top two rads (loft extension) were not heating up so I'm guessing that the lower rads (ground floor seems to be first from the boiler) are nicking all the heat, so I've turned the LV right down on these and opened the loft ones fully. Will go and check in 10 mins

SB

 

[sparkybird]

OK, so the top rads are now much hotter (not scorching, and they are slightly colder at the bottom than the top). To achieve this I have had to pretty much shut off the LSV on all the other rads - but on checking the difference in temp on the TRV and LSV on these is not much difference and in one or two cases the LSV is higher by 15 F even though the TRV is fully open.

The only two I've not adjusted are two towel rails (no TRV) and can't see how to adjust the LSV on these. They are both nice and hot. Could these make a difference?

 

[D_Hailsham]

The top of a rad will always be warmer than the bottom. If there is a patch of very cold in the centre at the bottom, it means there is a build-up of sludge.

If the LS valve temp is higher than the TRV end, it just means they have been put on the "wrong" ends. This does not matter; you balance as normal using the LS valve.

Did you remove all TRV heads when balancing?

Can you post a pic of the valves on the towel rails?

Current Building regs mean you should have TRVs on towel rails; but it's not compulsory for you to upgrade.