Solder Joint and freeze plugs

Hi all,

I am adding a radiator and have got as far as having the radiator on the wall, mostly plumbed, flushed out in case I had left any swarf and such in there and pressured 10 10 BAR to check for leakyness.

Now I just need to connect it to the rest of the system, for which I intended to freeze the pipes, cut and add a soldered fitting to them.
However, in one of my rare "stop and think" moments, I wondered if this is a wise move. If I was to freeze a pipe (vertical) and then proceed to cut below the ice plug, will I just end up having a lot of mopping to do as soon as I go near said pipe with a blowtourch? Surely the heat will just travel up the copper and melt the ice?

Would I be wise to go and purchase compression fittings for this last little bit of the job? or even a couple of 15mm compression fitting isolators? Or, am I just being paranoid and it will all be fine provided I freeze far enough away from the soldering?

T.I.A.

Firstly it will melt the ice and secondly the water in the pipe will stop the pipe getting hot enough for the solder to run properly within the fitting. You will have to go with compression or push fit.

Also I wouldn't fit isolating valves to heating pipes. In my experience the constant heating and cooling hence expanding and contracting always tends to end up with the valves leaking from the centre. As a personal rule I never fit balofix valves to heating pipes. They tend to end up with having to drain down in the future to remove them so I find it best to just bite the bullet and drain down. Do it once and do it right. This has always served me well.

The Rothenberger Turbo II freezer suggests no soldering within 450mm (18") of the ice plug. I think that's OK if you are quick, but personally I'll only solder:

a. Within 3 feet if the plug is level with or above the joint;
b. Within 2 feet if the plug is vertically below the joint;
c. If I can use a pipe expander to create a joint which only requires one solder ring. (For either a. or b.)

If you could freeze the pipe well away from the radiator, perhaps under floor boards, you could take the risk. Good luck.

Thanks all.

I think I will go for compression fittings for now. Unfortunately, I can only freeze above where the join will be, on vertical pipes as my house is built on a slab so all pipework is under the upstairs floor and this is a downstairs rad. I do not want to try to get the bathroom tiles up to get to the pipework up there.

I am reluctant to drain down at this stage as there will be some major work on the heating next summer which will involve draining down anyway. for now I just want a bit of heat in an extra room for this winter.