Repairing MLCP pipe without pressure too

[andyscotland]

Called out by my mother in law this weekend to no heat in her system. Discovered system was emptying as fast (faster) as the header tank could fill.

 

After an awkward wriggle under the floor, I discovered the original "plumber" has made no attempt to crimp the connection on this elbow onto the pipe to the  external drain down valve (at basically the lowest point in the system 😱) and it has evidently decided this weekend to move a bit and turn from a slow leak to a fast one. By my calc I think we've lost at least 200L of water under the floor since yesterday. God knows how much since this was done a few years ago.

 

 

 

I do not own/have access to a press tool for this connector. I am not at all convinced I'll find a plumber willing to wriggle the extremely tight subfloor route to get to it.

 

Any ideas? If I cut the pipe immediately above the elbow is there a compression elbow I could use instead?

 

Pipe has no manufacturer listed afaics, printing says "005m UFH MULTILAYER PE-RT/AL/PE-RT butt-welded PIPE TYPE I 16x2.0mm T=85°C P=10bar ISO 21003 CLASS 2/10bar,5/10bar 04:31:43 10/09/2019".

 

Argh!!!

 

No wonder my own project is years behind schedule  constantly having to fix up after "pros" elsewhere 🤬

[Nickfromwales]

You can cut the T out and revert to compression 16mm fittings to connect this lot back up.

 

You use 15mm comp joints but they have 16mm nuts / inserts / olives to adapt from 15>16mm. A lot of decent merchants carry these nowadays if you just ring around. 
 

Not sure how much pipe drops out of the T so hard to advise. Can you take that bit of insulation off to show what ‘we’re’ working with? 

[dpmiller]

MLCP fittings seal on the inside of the pipe don't they? I'd be tempted to fashion something up to put a crimp on the external sleeve- a U-bolt tightened down on it a couple of times maybe?

[Nickfromwales]

12 minutes ago, dpmiller said:

MLCP fittings seal on the inside of the pipe don't they? I'd be tempted to fashion something up to put a crimp on the external sleeve- a U-bolt tightened down on it a couple of times maybe?

Needs to be equal pressure opposing on all sides so the fitting and insert don’t deform. 

[andyscotland]

2 hours ago, Nickfromwales said:

You can cut the T out and revert to compression 16mm fittings to connect this lot back up.

 

You use 15mm comp joints but they have 16mm nuts / inserts / olives to adapt from 15>16mm. A lot of decent merchants carry these nowadays if you just ring around. 

 

Thanks - if I'm reading that right sounds like the pipe takes an insert (like it would if Hep2o/speedfit/etc, but obviously for a 16mm pipe) as well as the compression fitting?

 

Presumably my normal plastic pipe cutter will cut through it ok?

 

2 hours ago, Nickfromwales said:

Not sure how much pipe drops out of the T so hard to advise. Can you take that bit of insulation off to show what ‘we’re’ working with? 

 

I don't think I have another commando crawl in me today. I was half expecting to see the "who dares wins" crew waiting for me when I made it back out the hole earlier. As part of the works she had done they fitted fancy wooden flooring across the whole downstairs so the only remaining subfloor access is though a small cupboard a looong way away, via several very small holes in the subfloor walls🤦‍♂️

 

I'd say between the ends of the crimps on the T and the elbow there is probably just enough (but not much more) to get to full insert depth on a compression elbow.

[andyscotland]

Phoned round merchants this morning and - after blank-sounding noises from the first 3 - found one who had what I needed, exactly as @Nickfromwales described. The insert is part of the adaptor rather than being a separate thing as I'd first imagined.

 

Thanks very much for the advice @Nickfromwales - I might have given up after the first couple of calls if I'd not known for sure the part existed.

 

Bought enough to replace the T if I had to (not crawling down here twice) but there was enough length on the stub to just swap the elbow. Went together very easily, now just lying in the wet dirt waiting for the system to refill enough to do an initial leak check but it feels very secure.

 

Now found a new go-to plumbers merchants!

 

Couple of photos to give others confidence if ever in this position.

 

Here's the adaptor with insert, split olive & oversized backnut (obviously the insert pushes fully into the pipe, just showing what it looks like):

 

And then the finished joint:

 

[Nickfromwales]

34 minutes ago, andyscotland said:

Phoned round merchants this morning and - after blank-sounding noises from the first 3 - found one who had what I needed, exactly as @Nickfromwales described. The insert is part of the adaptor rather than being a separate thing as I'd first imagined.

 

Thanks very much for the advice @Nickfromwales - I might have given up after the first couple of calls if I'd not known for sure the part existed.

 

Bought enough to replace the T if I had to (not crawling down here twice) but there was enough length on the stub to just swap the elbow. Went together very easily, now just lying in the wet dirt waiting for the system to refill enough to do an initial leak check but it feels very secure.

 

Now found a new go-to plumbers merchants!

 

Couple of photos to give others confidence if ever in this position.

 

Here's the adaptor with insert, split olive & oversized backnut (obviously the insert pushes fully into the pipe, just showing what it looks like):

 

And then the finished joint:

 

Bingo.