Balancing rads - 2 queries

[spursfan323]

1. Do I need to remove the cap of the LSV in order to adjust it? A lot of articles advise to do so, but I can't see any point. The cap seems to adjust the valve fine.

Untitled

• spursfan323
• 6 Nov 2011
• 1

Untitled

• spursfan323
• 6 Nov 2011
• 1

2. Do I measure the temperature of the (vertical) pipework leading to the LSV/TRV - or the valve/pipework between the LSV/TRV and the rad?

Thanks.

 

[matt1e]

Hi

If the other end of your rad has a TRV on it then that is not a lockshield valve
(well it is but it has the wrong top on it)
it should look like this

what you have at the moment is a lockshied with a manual adjuster on it, so as you have said,no need to take it off to adjust, you should try to get a proper cap for it though

you measure the temp on both sides of the rads (pipes) and note the difference

Matt

 

[D_Hailsham]

2. Do I measure the temperature of the (vertical) pipework leading to the LSV/TRV - or the valve/pipework between the LSV/TRV and the rad?

You measure the temperature of the copper pipe coming out of the floor.

If you are using clip-on thermometers you can just clip them to the pipe. But if you are using an IR thermometer you should wrap some black insulating tape round the pipe and measure the temperature off the tape. This is because the reading will vary inversely to the brightness of the surface (polished copper will show a lower reading to dull copper) and paint will also affect the reading. IR thermometers are calibrated to a black surface.

 

[spursfan323]

Brilliant, thanks a lot to you both.

I've timed the system and all 6 upstairs rads come on very quickly, pretty much simultaneously (give or take a few seconds) and all get piping hot.

The 6 downstairs rads take a few minutes to start coming on, and even then, with a few minutes lag between each one. One or two barely get hot.

Should I close the LSV's on ALL the upstairs rads by the same amount of turn, seeing as they all come on almost simultaneously?