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Identifying LSV valves

I have missing caps on many radiators - and ones that are there seem t

indicate LSV valves on different sides.

How can I identify which side is the LSV valve?!

Help

-- nico62

Reply to
nico62
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If you've got ordinary valves (as opposed to thermostatic valves) on the other side, it doesn't really matter which is the LSV - although it is perhaps more usual to have it on the outlet side.

When the radiator is on, feel the two pipes. The inlet pipe will be hotter than the outlet. Designate the valve on the cooler pipe as the LSV.

However, it is probably more important to have a knob-operated valve in a convenient place so that you can turn the rad off easily when required. If this is more easily achieved by having the LSV on the inlet and the knob on the outlet, then so be it.

Reply to
Set Square

They are actually identical valves with different functions. Doesn't make a difference IMHO which one you use to pre-set the maximum flow rate through the rad apart from perhaps noise.

Reply to
Dave Plowman (News)

It doesn't matter. However, you should consider replacing one side with a thermostatic radiator valve, except any rooms that have room thermostats.

Christian.

Reply to
Christian McArdle

Thanks for all the help above... having set output valves as LS through whole system, I have three rads that will not come on. I hav tried: Shutting valves on other rads (leaving LSV's alone) Shutting some valves (upstairs then downstairs)

All to no avail.

I have bled water out and tried valves - and they seem to be working a the water flow stops and starts ok...

The in pipe of the one I assume to be first in line of the three did g mildly warm - but it was so fleeting I have not been able to reproduce

Any ideas for what to try next

-- nico62

Reply to
nico62

Please explain in detail exactly what you have done.

Did all the rads get hot before you started?

Simply designating a valve as a LSV doesn't, of itself, change anything unless you then go on to change the setting of the valve.

Have you followed the procedure for balancing the rads?

Reply to
Set Square

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