How do I remove a radiator without a lockshield/union nut?

6 Mar 2011
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United Kingdom

Apologies if this is somewhere on the forum or Internet, but for the life of me, I cannot find anywhere that describes what to do. Here are two photos of each end of the radiator in question that I was attempting to remove:

Now, I understand the left side, and am unsure what to do with the right side.

So far I have:

- turned the boiler off
- switched the boiler fused spur off
- turned the water stopcock off
- turned on all the taps until they drained dry
- attached some clearflex/tygon hose to the draincock on the kitchen radiator and put the other end of the hose near the drain outside
- opened all the TRV valves in the house to maximum
- opened all the bleed valves in the house from upstairs down to downstairs
- waited for several hours for the system to drain until barely a trickle flows out of the draincock/hose

I was about to undo the union (?) nuts off the sides of the radiator with an adjustable spanner and looked at the right hand side of the radiator above and am stumped as to what to do.

The massive nut caked in paint seems like it's part of the radiator and I tried undoing it with a pipe wrench (the slip-adjust simple type) and it didn't seem to want to turn.

I bought 4 female end caps which I would think would cap off the pipes/valves when the radiator is removed, but what on earth do I do on the right side? It doesn't look like a (normal sized?) female end cap could fit on what would remain if I managed to get the nut undone at that end.

We've got plasterers booked for 8am Saturday to plaster the lounge, so I'm keen to get the radiators off in time for then. We're also planning on replacing them with new ones.

The remaining radiators in the house all have lockshield + TRV stats on them, with the exception of the bathroom radiator, which appears to have two lockshield valves.

It might be painfully obvious as to what I should do, but as I've never seen a radiator plumbed in like this, and the fact that it's caked in paint, I can't see what should undo.

Is it a plastic compression fitting or something? If it is, can I undo it and get some sort of compression fitting plug/cap?

If not, any ideas?
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Seems you MAY hae a one pipe system!

Regardless you will need to drain the whole system.

Then perhaps you may be able to fit some lockshield valves or temporary caps!

Forget about the paint encrusted mess that is screwed into the radiator.

Undo the fitting on the pipe itself, and put a compression cap on there. You may be able to reuse the old nut and olive with a new cap.
If not, cut the pipe just below the nut, clean it up and fit a new valve - which is what you will need to do anyway for the new radiator.
Brilliant, so I'm on the right track... system is drained, and fine with getting new valves when it's time to fit the new (yet to purchase) radiators.

As I don't really know what the pipe fitting is, is it a standard size? Can I go to B&Q tomorrow and get a compression cap to fit, or are there a few similar sizes? I suppose if there are a few sizes I can just buy one of each!

Pipe itself seems to be 15mm diameter... gonna have a look at loosening the small nut...

edit: going to leave it til tomorrow as not sure what's going to happen when I undo the nut, it could break, and I need sleep!

edit2: woke up and got a rotary tool on the go and took as much paint off as I could without making too much noise at 7am. Can see a bit clearer how the pipe joint works now, and tried twisting the small nut and it rotates (was a bit worried it might be soldered).

So, I'll drop by B&Q on the way back home to see if they have any caps that look like they fit, and get a straightforward compression cap to go over a bare pipe as a guaranteed-to-work backup plan.

Cheers again for the help! :)
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It is a Conex compression fitting. It will be 1/2" BSP. All 15mm compression fittings are 1/2" bsp thread at the compression end.

Get a 15mm compression stop end:

Remove the nut and olive and screw it into the nut on your pipe.

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