Iso valves leaking

[Scott M]

I wanted to do some work on my ensuite shower but no way to isolate it. I removed a bit of platerboard from the wall in room behond it to expose the pipes (gery plastic Hepworth 15mm) and got a plumber out to fit a couple of isolation valves. Both valves are leaking very slowly, just a drip over a few hours. He has been back a couple of times and tightend them, put some paste around the pipe and valves but it is still dripping. He said they are just difficult to get to seal up.

Any advice as to what I can do now? Are Iso valves on plastic pipe (with inserts) the best way? Would the Hep2O valves work better or should I maybe take them off and put some PTFE tape on the threads? Would I just make things worse?

Thanks

 

[Gasmk1]

Presume he has used compression has he used metal inserts as the plastic ones will probably malform when tightened too much may be best as you say to use the hep ones or replace a small section in copper and use compression. I would use the hep ones as otherwise there would be too many joints

 

[WC1]

Plumbing is sometimes difficult but I don't know any plumber who'd be able to leave a leak like that.
He sounds more like a diyer than a plumber !
Brass iso's aren't designed for plastic pipe.
I always try and match fitting to insert to pipe.
Did the "plumber" use inserts - always needed on plastic pipe.

 

[Scott M]

To be fair, he is a local plumbing and heating engineer with a good rep. I don't know what inserts he used but he did say you can treat the plastic pipe just like copper with these things but they can be difficult to get proper seal.

The drip is very slight and evaporates before it gets enough to run down the pipe, it just annoys me.

I didn't want to take them off and put the Hep shut off valves on if I am just going to make it worse but may just give it a go...

 

[WC1]

Get him back. Imo

 

[ShaunCorbs]

Yep get him back it shouldn’t leak get him to cut the pipe 2” further down and re make the joint

 

[Ric2013]

Your plumber is right. You can use compression onto plastic and it usually works well. I think one manufaturer claims sometimes compression fittings have short insertion depths and if so, they won't work, but otherwise all should be well.

But if he's a plumber, leaving a leak is never acceptable so he needs to sort it.