Plastic vs Copper pipes for radiators

[Alexphd1]

16mm mlcp (same as picture above) but thats with a standard 15mm danfoss trv.  This is the uponor part for connecting 16mm to a 15mm trv or lockshield. https://www.underfloorstore.co.uk/product/uponor-compression-adapter-mlc-uk-16-15mmft

[Onoff]

My bathroom towel rail is fed from 16mm Pex-Al-Pex. 16mm Pex-Al-Pex to 15mm elbow:

 

 

 

Hole filled with CT1 & covered now with a chrome pipe shield:

 

 

I really hope that compression elbow in the wall doesn't leak!

[Simtronic]

I have used those fittings on all my underfloor heating and fan coils and not one has had a drip. 

[Onoff]

14 minutes ago, Simtronic said:

I have used those fittings on all my underfloor heating and fan coils and not one has had a drip. 

 

Good to know.

[ruggers]

11 hours ago, Alexphd1 said:

16mm mlcp (same as picture above) but thats with a standard 15mm danfoss trv.  This is the uponor part for connecting 16mm to a 15mm trv or lockshield. https://www.underfloorstore.co.uk/product/uponor-compression-adapter-mlc-uk-16-15mmft

Thanks, I didn't think it was as simple as that, so it's just a pipe inset that slides inside the 16mm pipe and the tapered end fits inside a standard 15mm compression fitting or lockshield. The nut on the 16mm pipe has a thread that fits the 15 compression fitting?

 

This looks the same as the link you posted too. https://pswtradesuppliers.co.uk/brass-compression-fittings/89-adapter-16mm-pipe-x-15mm-compression-fittings.html

And at the manifold end, just use 16mm eurocone fitting with 3/4 thread like this: https://www.underfloorstore.co.uk/product/warmus-compression-adapters

 

 

I didn't realise you can fit a range of pipe sizes from12/15/16 into an UFH manifold, you just buy a eurocone to fit your pipe size with a 3/4" thread and the taper takes up the gap and makes the seal if that correct.

 

 

 

[ruggers]

9 hours ago, Onoff said:

My bathroom towel rail is fed from 16mm Pex-Al-Pex. 16mm Pex-Al-Pex to 15mm elbow:

Hole filled with CT1 & covered now with a chrome pipe shield:

I really hope that compression elbow in the wall doesn't leak!

Theres not really any other way to do a sharp 90 degree from a wall into a towel rail where you need chrome pipe. But there shouldn't be too many of these in a house and compressions are fairly solid when used correctly. Nice job.

[Alexphd1]

It is that simple!

 

For the towel rail you get a 90 degree trv like this https://www.radiatorvalves4u.co.uk/trv/052-modern-trv-corner-chrome-thermostatic-radiator-valves.html?gclid=CjwKCAiAiML-BRAAEiwAuWVggpsfPYJtmzEb_AFX5j_qoQM7DnFvGIVCNheRcZskPKjvZ0hnlRJNehoCLgUQAvD_BwE  (never fitted this model can't comment on quality) that saves a compression elbow. 

Again we just used a two lockshields (I like the danfoss as the the Allen key bit to open is concealed by a cover) that turn back directly into the wall.

[ruggers]

Brilliant, so the corner TRV you sent will just give the same look as onoff's picture above but a few less joints & pipe. Feels like a big relief resolving this so i can now select some components.? a decent manifold.

[PeterW]

4 hours ago, ruggers said:

 

I didn't realise you can fit a range of pipe sizes from12/15/16 into an UFH manifold, you just buy a eurocone to fit your pipe size with a 3/4" thread and the taper takes up the gap and makes the seal if that correct

Some you can, some you can’t. The Wunda ones are good value as they have interchangeable connectors so you can mix and match hence why I suggested them. 

[Onoff]

3 hours ago, Alexphd1 said:

It is that simple!

 

For the towel rail you get a 90 degree trv like this https://www.radiatorvalves4u.co.uk/trv/052-modern-trv-corner-chrome-thermostatic-radiator-valves.html?gclid=CjwKCAiAiML-BRAAEiwAuWVggpsfPYJtmzEb_AFX5j_qoQM7DnFvGIVCNheRcZskPKjvZ0hnlRJNehoCLgUQAvD_BwE  (never fitted this model can't comment on quality) that saves a compression elbow. 

Again we just used a two lockshields (I like the danfoss as the the Allen key bit to open is concealed by a cover) that turn back directly into the wall.

 

I did get some of those originally from memory but I'd brought the pipes out too low and wanted the rad midway between floor and window cill.

[ruggers]

14 hours ago, PeterW said:

Some you can, some you can’t. The Wunda ones are good value as they have interchangeable connectors so you can mix and match hence why I suggested them. 

I'm going to contact them later today for some prices. They also have a good warranty compared to some if it's worth anything in the small detail. Thanks to everyone for the help.

[NewToAllOfThis]

Has anyone tried to bend plastic pipe with tight 90 degree angles with successful results, what is the tightest achieved and best way of achieving it and tools / method used 

[joe90]

1 hour ago, NewToAllOfThis said:

Has anyone tried to bend plastic pipe with tight 90 degree angles with successful results, what is the tightest achieved and best way of achieving it and tools / method used 

Usually done with one of these.  https://www.underfloorshop.co.uk/product/pipe-bend-support/?attribute_quantity=1&gclid=Cj0KCQiAzsz-BRCCARIsANotFgMarJVnVBWUJUhx06m2rTrmcDwhVBRXxKnuzl7bh9UPlF9MExRf2N4aAq7_EALw_wcB

[WillCram]

On 28/11/2019 at 18:59, Alexphd1 said:

Just out of curiosity are we talking a full UFH type of manifold or just a old school micro bore type manifold? We are using a ufh type manifold on our upstairs rads so we can control flow temp from thermal store and no TRV's just room stats via phone app. 

 

I dont like painted copper pipes as it's very rarely painted nice (always paint over the valve nuts etc). I do like plain copper or chrome pipe especially to towel rails etc. I would not have push fit fittings on show either as the pretty bulky. Most of our jobs we took the white mlcp (uponor) plastic pipe rite to the radiator valve and used a chrome nut. Never had any customers complain. 

 

Ps carpet had yet to be fitted at that job.

Hi, How did you you manage to insert the 16mm plastic pipe into the 15mm radiator valve, such that you could use the chrome nut? I'd love to do mine this way, but can't see how to do it. Did you trim/chamfer the end of the plastic pipe to make it fit into the valve body?

[Nickfromwales]

1 hour ago, WillCram said:

Hi, How did you you manage to insert the 16mm plastic pipe into the 15mm radiator valve, such that you could use the chrome nut? I'd love to do mine this way, but can't see how to do it. Did you trim/chamfer the end of the plastic pipe to make it fit into the valve body?

You cannot interfere with the pipe in any way, shape or form. So the answer to that is “NO” 

 

As per the link in that comment;

 

https://www.underfloorstore.co.uk/product/uponor-compression-adapter-mlc-uk-16-15mmft 

 

[WillCram]

35 minutes ago, Nickfromwales said:

You cannot interfere with the pipe in any way, shape or form. So the answer to that is “NO” 

 

As per the link in that comment;

 

https://www.underfloorstore.co.uk/product/uponor-compression-adapter-mlc-uk-16-15mmft 

 

Ah! Brilliant! Thank you so much Nick, and for such a prompt reply 🙂 Many thanks, Will.

[Nickfromwales]

7 hours ago, WillCram said:

Ah! Brilliant! Thank you so much Nick, and for such a prompt reply 🙂 Many thanks, Will.

No probs.

You can 16x15mm fittings in straight or angled, and I used to run 16mm under the floors, then have a compression 16x15 elbow, and bring 15mm copper up to a 15mm rad valve. I do not like to see pushfit pipe, but MLC is much hardier, so it’s fine for this instance, and then just down to personal preference.

[MikeGrahamT21]

9 hours ago, WillCram said:

Ah! Brilliant! Thank you so much Nick, and for such a prompt reply 🙂 Many thanks, Will.

 

And if you get the right shaped eurocone, you can do what I did, and pop that inside your TRV, so you get a direct 16mm connection to the 15mm TRV

[WillCram]

3 hours ago, Nickfromwales said:

No probs.

You can 16x15mm fittings in straight or angled, and I used to run 16mm under the floors, then have a compression 16x15 elbow, and bring 15mm copper up to a 15mm rad valve. I do not like to see pushfit pipe, but MLC is much hardier, so it’s fine for this instance, and then just down to personal preference.

Agreed; I'll be doing the same as you with the MLCP direct to the rad valves. I just like the idea of a seamless run under the floors, so no possibility of a leak. I was surprised by the toughness of the pipe (PEX-AL-PEX in my case) so yes, definitely fine for direct connection to the rad. Thanks again Nick.

 

[WillCram]

1 hour ago, MikeGrahamT21 said:

 

And if you get the right shaped eurocone, you can do what I did, and pop that inside your TRV, so you get a direct 16mm connection to the 15mm TRV

That was my thought too Mike. Thanks for confirmation; always good to know that someone has tried it and been happy with the result. Cheers, WIll.

 

[MikeGrahamT21]

1 hour ago, WillCram said:

That was my thought too Mike. Thanks for confirmation; always good to know that someone has tried it and been happy with the result. Cheers, WIll.

 

Yeah its bang on, but not all the eurocones fit.

 

Made this mistake on a single radiator that I was rushing to put on, in the end i thought the TRV design must have changed, it was only after i'd put a 16-15mm converter on, did I realise i'd just picked up the wrong eurocone!! Loosing my marbles i tell ya!

 

From memory the single seal ones are the ones that fit, the double seal ones are too wide.

[Nickfromwales]

Also, some TRV’s have a very short / shallow depth for receiving pipe vs the lock shields. 
Check that detail! 

[WillCram]

On 19/05/2022 at 07:31, Nickfromwales said:

No probs.

You can 16x15mm fittings in straight or angled, and I used to run 16mm under the floors, then have a compression 16x15 elbow, and bring 15mm copper up to a 15mm rad valve. I do not like to see pushfit pipe, but MLC is much hardier, so it’s fine for this instance, and then just down to personal preference.

Hi Nick, a further question if I may?!

I've ordered (and received) the Uponor MLCP (16mm) to 15mm compression fittings, but there are no split olives included. I'm guessing I need split olives in order to hold the MLCP in situ once pushed into the body of the compression fitting? Otherwise the MLCP is free to be pulled out, because the nut is not applying any pressure to it? (Pics included, One with the compression fitting as supplied (without the olive) and another showing where I think the olive is needed). Just seems strange that the olives wouldn't be suppled, which is why I"m probably overthinking the whole thing!

Cheers, Will.

[MikeGrahamT21]

6 minutes ago, WillCram said:

Hi Nick, a further question if I may?!

I've ordered (and received) the Uponor MLCP (16mm) to 15mm compression fittings, but there are no split olives included. I'm guessing I need split olives in order to hold the MLCP in situ once pushed into the body of the compression fitting? Otherwise the MLCP is free to be pulled out, because the nut is not applying any pressure to it? (Pics included, One with the compression fitting as supplied (without the olive) and another showing where I think the olive is needed). Just seems strange that the olives wouldn't be suppled, which is why I"m probably overthinking the whole thing!

Cheers, Will.

Yeah you 100% need one of those olives for the compression

[WillCram]

4 minutes ago, MikeGrahamT21 said:

Yeah you 100% need one of those olives for the compression

Thanks for confirming, I thought as much! Seems a bit cheap that they're not included!

By the way, I used the wrong nut in my photos. The actual one is narrower and deeper, as per the pics in your original post.

Cheers,

Will.