Plastic pipes for central heating?

[waltone]

Does anyone know or have used 'plastic piping' for the runs in a heating system, and is this method OK with the push-on fittings? My sons new house needs a new system of pipe work for the new boiler and wondered about this method. Are there any against's about it?
Thanks for any input
Waltone

 

[kevplumb]

however i am biased

just nipping out to catch a mole

 

[cozzmic]

Watch out for rodent damage nothing better than a mouse to turn it into a sprinkler system. Also have had problems in the past with air permeating through the walls of the plastic and b*ggering up the system with sludge. The newer stuff (barrier) should be Ok but I've seen too many knackered systems so I don't use it unless I get an A.I for it.

ps A.I (architects instruction)

 

[ChrisR]

I no will longer use push fit joints anywhere inaccessible. Have seen too many leaks for no apparent reason. Compression are OK if done right.
There are long-term concerns over how well the seals in pushfit joints will cope. They often rely on just one cheapest quality rubber O ring. Some makers give 20 year guarantee - they're guessing and hoping!

In fault conditions some boilers, on sealed systems, do not control temp well enough and the plastic pipe bursts.

 

[Agile]

In my view plastic pipe is unsafe to use on a sealed system because its bursting pressure and temperature can be reached during fault conditions as Chris says.

Perhaps I can put the question to you, unless there is a special reason to use plastic then why not use copper with all the advantages and none of the disadvantages?

Tony Glazier

 

[ChrisR]

Because, Tone, for us mere mortals without your omnipotent skills, plastic is a damn site quicker to use!

 

[mrscalex]

I've seen enough new builds round this way before the p/board cladding has gone up to know plastic/speedfit is a very common way of doing it. I'm told some plumbers like to make the drop from the ceiling in copper though.

This doesn't make it the correct or best way to do it before I get slapped-down for my amateur tuppence worth. I'm merely relaying an observation which would indicate high frequency of deployment.

It's also a good way of inserting perpendicular runs through joists post-build. Notching the under-side of a joist (assuming the ceilings are down for refurb) is a bad idea and trying to start a 10 foot length of copper into a 400mm gap is a pyhsical impossibility.

Soldered joints can fail too. My brother's recently flooded kitchen and collapsed ceiling is proof of that.

 

[Agile]

You are quite right it is used a lot. But that does not mean that it is the best material to use. There are a lot of shoddy new builds. Very little speculative building is to a quality spec.

Plastic is also rather surprisingly MORE expensive to buy than copper for the typical job.

I also agree with Chris that its usually quicker to install but then I dont want to do "cheap" jobs so I quote for copper and if the client wants a cheaper job he gets one.

I dont have much of a problem with plastic for water supplies or with quality metal pushfit connectors like Tectite and copper pipe for heating.

Tony

 

[PEDANTICVINDICTIVEMAN]

Hep20 barrier pipe is fine, even with standard pipe BG will put you on 5 star cover if system is installed correctly and inhibitored, who cares if it doesn't last forever, you aint gonna live forever either, when it needs repalacing it will be a job and keep someone employed later on, get a bad batch of copper tube and that can be a nightmare as well, seen whole houses with pin holed copper weeping away, coppers not what it was, too much recycling and impurities.

 

[Agile]

Now was it really copper or that copper plated steel which was used during the early 70s when the Ian Smith regime in Rodesia were unable to transport the Zambian copper to the rest of the world? A prudent plumber tests with a magnet!

I do have to say that I have never seen heating pipes made of copper pinholing yet although if I did I would first suspect too much flux left in the system. Perhaps some substandard copper may have leaked out!

Tony

 

[Nige F]

Good grief,Agile,you must be as old as me...One of my first jobs was with the plated thinwall steel in a big house with a tightwad owner. Still pass it sometimes and wonder about how long it lasted. I was the apprentice . Not agile myself,Arthritis got hold of me a few years ago..should have used kneepads. As to plastic. Did a house heating system for a friend recently. Tried out hep20 barrier on a 7 rad sealed system. Had to put leaksealer in as the pressure dropped slowly over and over. That`s what he wanted to use.

 

[ChrisR]

Fwiw the only pushfits I haven't seen leaking yet are the twistlock Speedfits. Their inserts add a few O rings too, though they mean using PEX (white) pipe which is horrible to use - needs lots of elbows which defeats the object. Nothing unusual about tectite, they still rely on a simple O ring and they squirt like the rest. The body is brass but that isn't what fails.
Copper joints do fail but only where they haven't been made properly, as far as I've seen.
It's probably true to say that most new CH installations are using plastic now, so I must be unlucky. I'm not happy with the number of joints which leak a LOT , or the number of installations where as in the post above, the pressure won't stay up.

Anyone (other than DIA) using Unipipe? That's the one with the aluminium layer so it stays bent where you bend it. I don't have the expensive crimp tool for it so have used their compression ends. Very little holds the pipe into the ends though, if you pull hard they come out. If the pipe were a bit cheaper I'd use it all the time, with the crimped ends & tool.

 

[doitall]

Time and money Chris, go out and buy one, or you can hire one on a job basis, ( tax recoverable)

 

[PEDANTICVINDICTIVEMAN]

Dont know whats wrong with u guys, I dont seem to suffer this leaking problem with Hep20, I do undo every joint to check it has joined properly though, particularly on 10mm joints, and use a smear of silicone lube to help on copper pipes.