CH system, copper v's plastic piping

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I'm replacing my complete system and had 4 quotes.
Combi system quoted by all.

BG rep says they won't use any pipes but only copper. No real reason given other than "it's proven" and plastic isn't. (He's by FAR the most expensive)

Two quoting "Hep" barrier pipe with copper tails into rads and boiler.

The last claims that barrier plastic pipe still allows oxygen to penetrate plus the push fit joints also allow oxygen into the system. Reckons he's seen plastic piped systems where the rads have corroded within 5 years or less. He proposes using pipe which is a combination of plastic outer and copper inner. He called it some name but can't remember it and I can't find anytrhing on the web relating to it.

Any truth in the last one's claims?
If do, will inhibitor prevent the corrosion

Thanks
 
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mmm

poly pip alone will ingress air, but barrier will not.

barrier is poly pipe but is laminated with metal to stop the air wotsit
 
Good question, interested in reply. Is speedfit really all its cracked up to be, long term and safe to bury between floors?
 
I use copper mostly, I have used barrier, it's cheap to run, fittings cost more but less of them used, sometimes it's preferable as can drill joists instead of slotting them.

I would use copper at home.

You'll get someone to use copper but without stick up BG prices if you keep asking.

If you do go plastic I don't like the new tectight sprint fittings, still recon tectight original is best push fit fitting. I just use hp20 barrier for all plastic applications with stainles inserts and tectight.
 
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Well I don't like plastic pipe, and will not use it, other than "Unipipe" which is a press fit. do a quick search on yahoo.

BG is always a £1000.00 dearer than anyone else anyway.
 
doitall said:
Well I don't like plastic pipe, and will not use it, other than "Unipipe" which is a press fit. do a quick search on yahoo.

BG is always a £1000.00 dearer than anyone else anyway.


each to his own do :)
 
each to his own do :)[/quote]

So it sounds like this is the general opinion - no real positives or negatives to either copper or plastic.

I'm happy to go with plastic but does anyone have an opinion on the "push fit joints also allow oxygen into the system" comment - just a salesman's scare tactic?

And if it CAN get in, how effective is the inhhibitor at preventing my new rads / boiler etc being eaten away?
 
tartansand said:
... does anyone have an opinion on the "push fit joints also allow oxygen into the system" comment .....
Yeah, bull-excrement.

Even if it was possible for Oxygen to percolate through the push-fit seal, it would be so minuscule in quantity as to be utterly insignificant. Contrast the tiny area of push-fit seals with the large area of pipe surface (were infiltration of oxygen can be a problem if a suitable barrier is not incorporated into the pipe wall).

Anyway if you're worried about push-fit joints you can use ordinary brass compression fittings with plastic pipe (half the price), but remember to use the liners the same as with push-it. You should add inhibitor to your CH system water anyway.
 
Yep each to his own is correct.

Known problems with plastic pipe and fittings.

They can and do fail, regularly. :(

Any marks or scores on the pipe will not provide a watertite seal.

The pipe should be supported along its length or it will sag between the joists (bit like curtain draps) as it heats up, this can and will present problems with air collecting in the high spots, and water sticking in the dips causing air locks and bad circulation, it will also make filling and draining a major problem.

Another big problem that is emerging is; rodent damage, it seems they quite like Hep 2° pipe.

Shucks, I wouldn't install it in my house, so why should I chuck it in yours.

Old dinasaur that still has some pride in his work.
 
doitall said:
....Another big problem that is emerging is; rodent damage, it seems they quite like Hep 2° pipe.....
How common is that? Or the plastic coating of electrical wiring being eaten through for that matter, despite the universal and long term use of plastic coated wiring. Unless there is a known rodent gnawing through cables/pipes problem in your area, you can forget about that.

Loads of plastic pipe and fittings have been installed throughout the world for decades now. for the most part it works fine, providing it's properly installed. My only concern is how it will all shape up in say 30 years time, but that won't be my problem (like Global Warming really!).
 
Plastic pipe is a different material to cable, and the little buggers have taken a fancy to hot Baths :rolleyes:

Perhaps you can remember Armaflex lagging and how they love that.
 
Last time I was at Center Parcs they had major problems with rodent damage of the plastics heating pipework beneath the houses.

They had 500 or so houses, mostly worcester highflow 400s, many full of sludge after just five years, because they were being constantly refilled due to leakage.

Rodents will knaw it, but if you don't have rats or squirrels indoors, shouldn't be a problem.
 
doitall said:
Plastic pipe is a different material to cable, and the little b*****r have taken a fancy to hot Baths :rolleyes:

Perhaps you can remember Armaflex lagging and how they love that.


doit is right i have had to go to a few knawed pipes, not enough to change my mind on poly though.

as for lasting thirty years is not the life of copper about 25?
 
Well, I'm quite happy using plastic pipe, though usually PEX and with compression fittings. In many situations it's just so much quicker and cheaper. Of course it looks naff when exposed to view, but there's no rule that says you can't mix and match as the fancy takes you (just keep plastic CH pipework at least a metre away from boilers). A bit of copper, compression joint, a run of plastic, push-fit joint, another bit of copper with soldered joints, etc... (But keep heat and flux away from plastic!).

PS. What's all this about knawing? Do you mean gnawing?
 

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