MLCP pipe system - any experience

[AJB Temple]

I intended to install a pellet burner for heating my new kitchen (presently in an outbuilding that I will connect to the house). I am having second thoughts and may use large vertical radiators as elsewhere in the house (I have replaced practically everything) like this:



I don't do central heating plumbing myself, so had a chat with my regular plumber. It is a 35 metre run each way through roof spaces to get to the furthest possible radiator point in order to connect back to 26mm copper from the external boiler (which terminates in the airing cupboard where there is a Megaflow system.) The boiler is due for replacement and will be resized to suit the full system and any likely additions.

All current plumbing is soldered copper, but because I have to do a 5 metre span for a connecting room that is not built yet, the plumber has suggested MLCP, either Imeti or Gerpex. I had never heard of multi layer composite pipe before. He reckons it is better than push fit, but requires special tooling (which he has). The pipe comes in insulated and uninsulated form. I would use insulated, largely because of the unbuilt span.

I am two minds about this, partly because it ties me to a plumber who has the tooling system (£2k he says), which I think may be tied to the pipe manufacturer as well. He is suggesting Gerpex or Imeti. We would still use soldered copper to connect to the rad valves.

Does anyone have any experience of MLCP? At present I have no idea of cost.

 

[Rorschach]

I don't have any experience of MLCP I am afraid however I think my general opinion still applies.
I wouldn't want to use anything that required specialist tooling to install/repair. It's all very well at the beginning, but what happens when something goes wrong or you need to make changes.

 

[Eric The Viking]

Do you mean 28mm copper? If so there is excellent lagging already available: We used Isover here (Armaflex on the solar as it needed to be more bendy).

I wouldn't use any pipe system that's pre-insulated simply because it's not adaptable enough - you can't choose how much insulation you get, nor access the pipework as easily if you need to modify it.

Run away from anything needing special tooling, unless there is some overarching value to you (not your plumber!) in using it. That said, the spot price of copper can't be low at the moment, so the pipe might be a significant cost.

There is a big disadvantage of larger sizes of copper pipe (above 22mm - that would be 28mm, 35mm and so on): it is very rigid, so can be a nuisance to fit. You don't bend it, you fit elbows and couplers. This increases the time everything takes, and you have to stand it off whatever your fixing surface is, to allow for the insulation. But the results are neat,

We had a small amount of 35mm in the house when we moved in, as the original CH plumber panicked I think, but it's now slowly being recycled into DX ports etc, for woodwork. I can't imagine you'd need anything more than 28mm.

Can you route the pipework through the inhabited bits of the house as much as possible? It's far more efficient from a heating point of view - even the best insulation leaks heat...

In our case we now have the boiler in the side attic (walk-in) of a three-floor house, so the pump is working against gravity. Even so, it works well. 28mm on the combined return, but we only need 22mm for each of the two main zones. A few years ago we downsized some of the piping, from 28mm to 22mm on the middle floor (a leftover from the old system we replaced), and that improved radiator temperature significantly.

The Isover insulation didn't used to be sold in sizes smaller than 22mm, but you can now get it as suitable for 15mm pipe. For one radiator (ground floor, low output in the scullery) I put flow and return in the same 22mm insulation sleeve (10mm pipe), as that made it easier to route and get through a roughly 60mm thick wall. It's probably the furthest from the boiler but works fine. I used Isover 22mm round the 15mm kitchen hot tap feed, under a draughty floor, and it completely cured the cool-down issue. If it was used late evening, at 6AM, there is still almost piping hot water at the tap, before it's had time to come down from the tank.

I don't think there is an overarching best answer, but I remain nervous of using plastic piping, because I'm an old fogey, probably.

 

[AJB Temple]

Thanks Eric TV. I was not being clear. We need to get back to the large size pipe that comes from the boiler (which is outside) to the Megaflow etc in the house. The other option is to T off copper elsewhere in 6th radiator system, but that is only 15mm and we don't think it will be efficient. I think the intention the polder has is to use 20mm MLCP from the airing cupboard. This will run under the floor of two bedrooms, than across what is presently a void but will be oak framed next year, into the loft space of an adjacent barn where it will be connected whatever rads I fit.

I don't mind plastic piping. The pipe feed to the house from the mains is plastic, and I have about 400 metres of it underground through the garden. The good quality push fit systems I think are perfectly OK internally, but I prefer copper (prices have shot up) whenever any pipework is visible.

Adrian

 

[clogs]

I've amazing success with HeP2O.....and other high qual plastic pipework....
I've used it for normal plumbing duties as well as underfloor heating.....
don't get stuck into specialist heating pipework cos in a few years things will change and nothing will fit or be able to add on....
other plastic pipework is made to work with copper pipe and ALWAYS will be....
on diff jobs I've gone from copper to plastic and back to copper because of the diff routes pipes will always have to take....
Just to add HeP2O will take from -15 to boilling.....and u can also use normal insulation...

 

[Spectric]

Hi all

I don't have any experience of MLCP I am afraid however I think my general opinion still applies.
I wouldn't want to use anything that required specialist tooling to install/repair. It's all very well at the beginning, but what happens when something goes wrong or you need to make changes.

I may be old school but have to agree with Rorschach, why use something specialised or vendor specific when you can use good old compression fittings or endfeeds on copper pipe. Easy to repair or modify in the future without having to source specialist parts and tooling. I believe that plastic pipe and push fit were developed to allow the modern property developer to cut cost and employ semi and unskilled workers rather than time served who want to do a decent job.

 

[Rorschach]

Hi all



I may be old school but have to agree with Rorschach, why use something specialised or vendor specific when you can use good old compression fittings or endfeeds on copper pipe. Easy to repair or modify in the future without having to source specialist parts and tooling. I believe that plastic pipe and push fit were developed to allow the modern property developer to cut cost and employ semi and unskilled workers rather than time served who want to do a decent job.

Plastic and push fit are not a cost cutting exercise, good quality plastic pipe and fittings is comparable in cost to copper and solder joints (though a bit quicker to fit I concede). Plastic has many advantages in the right situation, the most obvious example being you can bury plastic water pipes in your garden. Using plastic inside the house can allow for much longer runs with no joints, snaking easily around objects and allowing for easy modification and repair.
Copper also has many advantages, again in the right situation such as when you need resistance to UV light or something that might be prone to getting bumped or exposed to heat.

 

[AJB Temple]

Yes thank you Rors, but I know all that (though it is a fact that plastic is a LOT cheaper than copper currently). What I am after is actual experience of MLCP as it is an emerging system gaining wider acceptance.

 

[Rorschach]

Yes thank you Rors, but I know all that (though it is a fact that plastic is a LOT cheaper than copper currently). What I am after is actual experience of MLCP as it is an emerging system gaining wider acceptance.

My post was just a reply to Spectric really, and maybe for the benefit of others.

 

[Eric The Viking]

I had to google Megaflow. We have the same idea here, but with an extra coil from the solar system.

How far is the run from the boiler to the tank? The biggest losses are immediately next to the boiler and (obviously) the longest runs. Basically the hotter the water the more heat is lost from it. You do gain from bigger pipes in that respect, as long as everything is well insulated.

I would get as much insulation round the run to the tank as possible, plastic or copper notwithstanding. In our installation they sit next to each other, and the escaping heat dries the rest of the walk-in airing cupboard.

Like you I would be happy with plastic as a temporary solution (the HDPE used underground doesn't have the same issues as pipes in properties). But bear in mind the fun of finding a plastic pipe buried somewhere - with copper you can simply use a metal detector.

 

[AJB Temple]

Hi all



I may be old school but have to agree with Rorschach, why use something specialised or vendor specific when you can use good old compression fittings or endfeeds on copper pipe. Easy to repair or modify in the future without having to source specialist parts and tooling. I believe that plastic pipe and push fit were developed to allow the modern property developer to cut cost and employ semi and unskilled workers rather than time served who want to do a decent job.

The reasons are:

I need to bridge a span between buildings, the linkage not being built yet as per my original post. It is a great deal more work and risk to do a 35 metre run in copper, that I will beed to protect from risk through the entire winter outside. I can buy a 100m roll of composite pipe, fully insulated, and have hardly any fittings and hardly any risk of leaks. I am working to the application rather than a materials preference.

Secondly I detest compression fittings. They are bulky, ugly and a weak spot. My former FIL (now dead) was a commercial heating engineer and he taught me to bend and solder copper. I still have his tools - but not his skill. I could do it in copper and I still might, but the purpose of the thread was to seek experience of people using MLCP. The view of people who have never used MLCP may be interesting but don't actually help the problem I need to address with this site. But thanks for taking the time to post. Adrian

 

[Spectric]

Hi there

Adrian compression fittings may be bulky, some may think them ugly but they are certainly not a weak link. They are tried and tested and unavoidable, connections to boilers, valves and radiators are all compression as you know. What people are pointing out is that using new technology comes with it's risk and if there are not many people with experience of this MLCP then does that not tell you something.

 

[AJB Temple]

Thanks Roy. I suppose my point really is that I can do soldered joints and I have bending gear for copper pipe, so I see no need to use compression fittings to do long runs of 35 metres under floors. I think they always look awful when they are visible except for final termination to, in this case, bronze finished valves. I tend not to do plumbing work myself as I know my limitations and I have too much work on. I dislike the faff of all the draining down etc.

MLCP is quite a new product, relatively speaking, so I am not so surprised that no-one has experience of it. My gut feel is that it will become ubiquitous in high end developments and office fit outs, as it has many apparent advantages. I am not worried about being an early adopter of new technology and the plumber I work with on my projects is excellent.

For this part of my house, I will finish the fit out and that will be it. I will not alter it at all and so I am not that worried about future changes and fixes. However, I accept that there is a risk and that due to tooling it is beyond DIY scope. For that reason I may well make an insulated bridge out of soil pipe and run copper or push fit through, as I can do that myself at my leisure or get Ollie the plumber to do it.

However, I agree that a system that anyone can work on is better than one that requires specialised tools, in a domestic environment.

KR, Adrian

 

[MikeJhn]

Plastic pipe is used a lot in France, but the problem I have with any of these plastic pipe's in CH systems is the radius the pipe must take to come out of the floor slab with its associated corrugated conduit, it looks dam ugly.

Any pipework that needs to span 5M will need supporting even if its only a catenary wire, better if its more solid though.

Just a word on Pellet Boilers, they are noisy, and unless you have it hopper fed (hang ups are a regular occurrence) they are also labour intensive, humping bags of pellets is not a job for a senior citizen.

 

[AJB Temple]

Thanks Mike. I meant a pellet type "log" burner. We investigated replacing our oil boiler with a pellet type, as there are significant grants, but I would have needed to construct a building to house the fuel, so I decided against it.

The MCLP composite system comes in either coils or straight lengths. In this application it would be coming in a straight line at first floor level. I do realise the span has to be bridged. That is not a problem.

 

[Blackswanwood]

My wife is a director of a small house builder and they have just had a board meeting around our kitchen table so I took the opportunity to ask the director who actually does the building.

His answer is that MCLP is a great product as it’s quick to fit and doesn’t need heat which is in line with what you have said. The fittings are apparently quite expensive but he wouldn’t be surprised if it works out cheaper than copper at the moment which again is I think in line with what you have found.

His view is that any plumber or heating engineer will have most of the tools needed already and was surprised at the cost your guy has quoted.

It has been specified on other projects his main business have done and they have had no problems.

We have a wood pellet boiler - I don’t recognise the earlier comments about it being noisy etc.

I hope this helps.

 

[AJB Temple]

Thanks BSW. That is very helpful and thank you for taking the trouble to ask. I have seen Ollie (plumber) since and it turns out he meant he has £2000 worth of tools and fittings in stock, most of which is fittings.

Adrian

 

[HOJ]

I cant give specific advice, however as a business we adopted MLCP pipe, Uni Pipe/Emmeti, over 20 years ago, we have the capability to handle 32mm MLCP (hydraulic crimp tools and bender), probably got a couple of thousand £ in tools and stock at cost.

As BSW has indicated, and in my experience of working with others, (professional installers) most of us are geared up for using these products, a principal reason for using these systems is so we can comply with the strict site rules for controlled and restricted "Hot work"


Compression adaptors are available to connect to standard plumbing products so conversion is not a big deal, (but they can be pricey)

Also, they have an Aluminium foil layer, so can be detected with a pipe detector.

 

[AJB Temple]

Thanks HOJ.