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Radiator connector size

Looking at TRV and lockshields in Screwfix and BES, it seems the standard union with a radiator is 1/2". All the radiators in my house seem to be much larger than that - maybe 1". The radiators are all c1980 vintage. Is this a non-standard or old size?

None of the radiators have TRVs and many of them have weeping valves, so could all do with sorting. Am I going to have to try and find reducers if I want to use modern fittings, or might I even have to bite the bullet and replace the radiators entirely? thanks tony

Reply to
Tony
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Your old radiators are probably 3/4" BSP. They *could* be 1" BSP but that is unlikely. Bear in mind that these sizes refer to the *internal* diameter of the pipe, so the threads on 3/4" BSP are just over an inch in size.

If your old radiators are sound, there's no need to replace them - but do give them a good wash out with a hosepipe or pressure washer. You can buy

3/4" to 1/2" reducers from a plumbers merchant.

Also bear in mind that newer radiators with fins have a considerably higher heat output than the non-finned variety (which I suspect yours are) - so if you fancy having less of your walls covered by radiators, buy new ones.

Reply to
Set Square

On a TRV, the O/D of the thread that fits the rad is approx 1" - or more like 0.9". This is larger than the thread on the 1/2" compression fitting 'pipe' end.

A rad of this age will almost certainly be standard, so you're ok.

Reply to
Dave Plowman

On Thu, 22 Apr 2004 09:02:14 +0100, in uk.d-i-y Tony strung together this:

What you want to do then is remove the 3/4" tails and put the 1/2" ones that come with the new valves back in place. I'm not sure which bit you're looking at, there is the thread into the radiator and then the thread onto the valve itself, a picture of your rad maybe?

Reply to
Lurch

Small high output rads aren't a new idea. Thermapanel were making them 30 years ago. Are they still on the go?

Reply to
Dave Plowman

Agreed - but they're much more *common* now! (I only *suspected* that the OP's rads would be unfinned).

Reply to
Set Square

Your suspicions are correct... not a fin to be seen on any of the 24! radiators in the house.

I think now I might well go for new 300mm radiators rather than persist with the old ones - they're going in a completely refurbished room so it seems reasonably to put in shiny new radiators too. tony

Reply to
Tony

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