Radiator tails

[CPCUK]

This is another pretty daft question but I would like to know the following.

I've noticed that the lockshield valves are connected to my radiators with a large nut ie, outside diameter about 30mm. The tail is installed using a hex radiator key.
I have these:

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• CPCUK
• 9 Oct 2012
• 1

I went over my parents and noticed all there rads had lockshields with drain off on them but they connected to the radiator with a standard size nut, ie, 25mm.
Parents have these:

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• CPCUK
• 9 Oct 2012
• 1

Are these interchangeable? I would like to have the ones with smaller nuts if possible.

Also, is it a good idea to have drain off's on all radiators or is that just a waste?

Thanks[/img]

 

[Terry lambert]

You should be able to change the valves over, obviously using the tails that come with the new valves.

You should have drain Valves on all low points. There is a slightly different type of tail where the drain point is between the valve and rad, which would then allow you to isolate and drain that radiator independently a lot easier.

 

[denso13]

The nuts obviously aren't interchangeable but the thread size will be the same. Therefore you can change the complete valve, tails and all.

Drain offs on each radiator are useful if they are fed individually from above, for example, but not required if you have a main drain cock which drains all rads.

 

[CPCUK]

Thanks for your replies.

Currently the only drain off valve I have is on one of the rad's in the lounge. This rad is fed from a drop from the back bedroom. I was considering sticking them on all rads like my parents (her CH was quite a new install throughout) but if you guys think I'm wasting my money then I wont bother.

I have Drayton TRV3 valves on 11 or my 13 radiators and most of them seem to be a bit sticky so I purchased a load of TRV4's which I plan on installing. The lockshields I thought I'd renew at the same time as I drain the system down. Should I just buy standard lockshields and have just a couple of drain off's downstairs and with none upstairs?

The valves with drain off between the valve and valve are like this:

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• CPCUK
• 9 Oct 2012
• 1

The only trouble with using this I think is that the existing pipework needs to be moved slightly to make the connection!

Thanks

 

[Terry lambert]

Yes the tails are a little bit longer.

Lock shields and then a drain off on every drop would be fine.

Pointless to have them like this on upstairs rads

 

[Madrab]

The nuts obviously aren't interchangeable but the thread size will be the same. Therefore you can change the complete valve, tails and all.

Not sure if it would be relative in this case if your rads are not too old but have come across 1/2" rad tails on older ones as against 15mm, though if they were, it's just a case of swapping out the tails, job's a goodun

 

[CPCUK]

Thanks again for your info. I think I'll be sorting this out this week.