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Postby Britannia » Sat Nov 08, 2008 3:46 pm

I am currently training as a plumber and am unsure if the TRV should be fitted to the flow side of a radiator or the return.
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Postby plumbbob » Sat Nov 08, 2008 10:40 pm

If you read the text book, it tells you to always fit the TRV in the flow side the same as the on/off valve it replaces. Indeed if older TRV's are installed in the return side, because they were directional, they may make a loud noise. Newer valves needed to be mechanically "set" for flow direction before installation. Now as far as I know, all new TRV's can be fitted in either flow or return without adjustment.

I personally prefer to fit them on the end of the rad that is the most open to the room regardless of flow direction. My colleague meanwhile, for neatness, prefers to always install them on the right hand side of the rad.
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Postby Steve the gas » Sun Nov 09, 2008 4:34 am


If the TRV is Bi-directional then either end - flow or return,but, if not the flow,

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Postby sparx » Sun Nov 09, 2008 8:00 pm

I understood from my controls course that either will be ok but if fitted on flow side should be installed horizontally, if on return vertically, as higher temp on flow will cause valve to cut off early if sensor too near rad.
A mere leckie (who does boiler controls as a major part of my work) so I will bow to those with more up to date knowledge,
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Postby htg engineer » Mon Nov 10, 2008 11:37 am

The majority of them can be fitted to either the flow or return. If in doubt check the manufacturers instructions.

As with Plumbob - I also fit the TRV to the end i think would be best for example to allow for easy access.

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Postby Britannia » Tue Nov 11, 2008 10:56 am

Thanks guys for your help
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