Radiator Bodgery

[GMM]

I know this is an outrage and I should be hung drawn and quartered for even contemplating it but needs must (!)

I have an old 6-foot single radiator in the bathroom which is beyond the end of its life and showing (since yesterday) a small rust hole/leak. I have a 1m double that would do the job in its place. I'm planning to renovate the room comprehensively later this year but currently have very little time available to do any major surgery on the CH system.

What I would like to do is join some copper or plastic pipe to the old valves then mount the new radiator to this. This will save me draining it all down, lifting the floor and re-routing the pipework for the moment. It will also, of course, look dreadful but it's a temporary measure so I'm not worried about that.

I know you can get extending tails, but they wouldn't stretch this far, so the question is, what do parts I need to join the 'radiator' side of a valve (TRV and LS) to 15mm copper tube? I'm imagining it will be something like a 3/4 tap connector but I'd rather make sure I have the right thing before I get up to my eyeballs in the job!

Normally I would just go and chat with my local PM but I went round there this morning and to my horror they have closed down, so I need to go and cultivate a new one somewhere.....

Cheers chaps

[news]

If this is the same as the one I just did then the connection to the valve was 3/4 BSP and the tail into the radiator was 1/2" BSP, probably tapered thread but PTFE string worked fine.

The 3/4" Nut should fit over a 22mm pipe and olive for the valve end then a 15mm x 1/2" male connector should fit the radiator end. Then you will need a 22mm to 15mm reducer to join the pipes.

AJH

[Chris Hogg]

Stuff all that!

If you're only after a temporary bodge ATM, see the recent thread started by Road Hog on the 21st Feb on repairing a pinhole leak in a radiator. The best solutions IMO were to patch it with a bit of plumbers putty, which will stick to wet surfaces and 'goes off' after being kneaded, or the other solution, to use a self-tapping screw in the pinhole, probably with some sealing compound in the thread as well, and remembering to shut both valves on the rad while the putty or whatever is hardening. Either are quick and easy solutions, to tide you over for the refurb later in the year, and much simpler than the complex arrangement you seemed to be planning.

[Andrew]

When one pin hole appears, you can bet that a few dozen more are lurking..

I would change the rad. One end can use the existing lock shield fitting, and on the other side just fit an inline trv or lockshield so the compression outlet/inlet is horizontal. Just use a length of copper tube horizontally to reach the existing vertical pipe which will have an olive previously used to connect to the original 90 degree trv or lockshield. Use a 90 degree compression instead.

[Chris Hogg]

Well, quite, but AIUI the OP only wants a temporary fix until he does a proper job later in the year.

[Roger Mills]

As others have said, it may be easier to put a temporary patch on the rust hole.

But, if you really want to do what you suggest, it is perfectly feasible but the fittings you need will depend on what type of tails your current valves have.

All tails have 1/2" male BSP threads at one end, which screw into the radiator. Older valves have conical connections between valve and tail - and these come in two different sizes and several different threads!

Newer valves have 15mm compression fittings - both for the tail and for the supply pipe. This enables such valves to be used in either orientation.

I'll deal with the compression type first, because these are easy. All you need is a length of 15mm copper pipe and a 15mm straight compression coupler each side. Remove the tails from the old rad and fit them to the new one, leaving the olives and nuts in place. Use the couplers to attach a length of pipe to each side of the new rad - making use of the olives and nut already on the tails, thus leaving a spare olive and nut each side. Cut the pipes to length to marry up with the valves, and use the spare olives and nuts to attach them to the valves.

If you have the conical fittings, it's best to keep the tails with the valves. So you'll need two new plain tails, two couplers and two 1/2" female iron to 15mm compression fittings. Remove the tails from the old rad and re-attach them to their valves. Screw a 1/2" female iron to 15mm compression fitting onto each tail. Fit the new plain tails to the new rads and fit a compression coupler onto each tail. You then just need to fit a length of 15mm pipe between each pair of compression fittings.

You will, of course, need to use PTFE tape on the tail threads before screwing them into the rads and, if appropriate, on the tail to female iron connections.

[Roger Mills]

Except that the OP wants to avoid any draining down - so that means that the valves need to remain in their original positions.

In my previous post I had assumed that the OP wanted the temporary replacement radiator in the middle of the gap left by the longer original - probably because he mentioned pipes (in the plural) for extending the reach of the valves.

But if it's acceptable to put the replacement rad at one end or other rather than in the middle, the existing tail, etc. can be used that end

- only requiring the other end to be extended.

[Tricky Dicky]

If the OP needs to take one valve of a pipe in order to put in a bridging pipe, what's wrong with pipe freeze?

Richard

[Dave Liquorice]

If the system is open vented, block the feed and expansion pipes (you can get tapered "bungs on strings" desigend for 15 and/or 22 mm pipes). Shut both valves, drain the rad, you can then remove *ONE* valve and very little water will escape as no air can get in. A vertical up opening one won't glug but may have a little flow, A horizontal or vertical opening down pipe might glug, and if one does a fair bit of water may emerge...

Provided there is only ever one open to the air point in the system at any one time you should be able to do one end, shut that, then do the other.

In theory if you de-pressurise a sealed system the same should apply but I've never had a pressurised system. I have succesfully used the above technique on an open vented system though.

[Brian Gaff]

And byy the time you have done it you still have air in the system and might have well done the whole job in the first place! I hate CH systems. Brian