Problem with radiator valves

Rhino666

Hi

The radiators in my house were fitted 25 - 30 years ago and unfortunately some of the valves need replacing - leaks etc.

I bought a load of new valves with the idea of leaving the large nut and tail in the radiator and the compression nut and olive on the 15mm feed pipe and simply slot in the new valve body.........Good idea at the time but no cigar.............The threads on the feedpipe compression nut and the large radiator tail nut are finer than the threads on the new fittings !! Tried to find valves with the same threads at the Plumb Centre, PTS and Coventry heating and plumbing but no-one can help.

Firstly can a plumbing expert possibly suggest a supply for these valves, which appear to be totally standard apart from the finer pitch threads ?

Failing that I will need to use the new valves. It is easy to change the radiator tail and large nut but the problem will be with the 15mm feedpipes, where the olives have been forced into the pipe with tightening. Is there any way I would be able to cut off the old olive and create a new seal with what is now probably a slightly deformed pipe ? I know I could cut the pipe and solder on an extension but I want to avoid this if at all possible.

Thanks

Rob

alanobrien

I went through this exercise myself a while ago except i had some ancient spacers to deal with as well.

I would advise replacing the whole valve, including the radiator tail. removal and replacement of radiator tails is quite easy but you may need to get a special spanner for it at BandQ etc as they may use a lug drive to tighten them up.

You will also need to seal the threads with PTFE tape or sealing compound (tape is easier).

As regards the existing olives on the pipes you can cut these off with a junior hacksaw providing you do it carefully. Clean up the pipes with wire wool and fit the new nuts and olives. Thats all i did with a pressurised system and it works fine.

Rhino666

Thanks for the reply Alan

I am mainly worried about the distortion on the 1.5mm pipe caused by the compression nut tightening on the old olive. There is no excess play in the feed pipes to allow the pipe to be cut and reused. Removal of the old olive would be quite easy with a dremmel but surely the distortion caused by the old olive would make seating a new olive impossible even with sealant ?

I have tried to find a UK plumbers forum without success - does anyone know of one ?

Thanks

Rob

alanobrien

Rhino666 wrote:

Thanks for the reply Alan

surely the distortion caused by the old olive would make seating a new olive impossible even with sealant ?

Rob

It shouldnt. The olives are generally quite soft, softer than the pipework. I did exactly what you are describing to 14 radiators (28 valves) and never had a single leak when i fired up the new pressurised system

But as i mentioned, i did carefully remove the olives and cleaned the pipe work extensively with wire wool.

Other than that i did nothing special.

Fleeting_Glimpse

Hi

You need to replace the whole valve.

When you put the olive on the 15mm pipe work....wrap a few strands of PTFE tape around the olive and the thread of the radiator valve...to make a 'seal' if you know what I mean.

Turn all the valves off ( both ends ) and make sure all the bleed nipples are shut before turning back on.

Open each valve, check for leaks, fill up the rad and check for leaks again...then move to the next rad.

Check for leaks again when the system is hot and again when cooled

robv_3

If the copper pipe is mis-formed you will need to cut the copper tail and add a new bit of pipe using a coupler.

uncle_buck_3

A good tip for removing old olives without damaging the pipe is to only hacksaw about ¾ of the way through the olive, then use the blade of a flat bladed screwdriver in the slot you have cut to twist & snap the olive, it should then just slide off the pipe.

mdbs

If you have damaged pipes (from the compression of the olives) you have little choice but to replace, however, if you buy "TECKTITE" not sure that the spelling is correct, these are a push fit coupler that is also "Brass" coloured and looks quite nice, far nicer than an normal compression fitting.

This method makes it all very quick and easy