Plastic or Copper piping?

[petercj]

Agreed. Plastic has its place, especially for heating systems in new builds. The problem with plastic is it's perception by non-plumbers, who think that soldering is the hardest part of the job (lol) so therefore, plastic pipe means they are instantly competent plumbers.

On a side note, please correct me if i'm wrong, but i thought that sludge in a system was a byproduct of the reaction of ferrous, non-ferrous metals, moisture and air within a heating system, which the inhibitor, well, inhibited. Therefore, less copper = less sludge?


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Magnetite aka sludge (the black stuff) is produced by steel/iron radiators

 

[TBServices]

Magnetite aka sludge (the black stuff) is produced by steel/iron radiators

Yes, but is it not the chemical difference between the copper and the steel that creates the magnetite? I can't remember where I picked this up, probably from college.


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[petercj]

Yes, but is it not the chemical difference between the copper and the steel that creates the magnetite? I can't remember where I picked this up, probably from college.


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Magnetite in radiators is a product of corrosion, and the more oxygen there is in the water the faster the process will be - IF plastic pipe did allow air to pass, then that would explain excessive sludging. I've never heard that plastic will reduce the tendency for magnetite to form.

 

[SimonG]

Nowt wrong with plastic, when installed correctly. Trouble is most of the time it's thrown in by people who don't read the mi's. It's a nice addition to the arsenal and has it's place. I only have two issues with plastic, vermin chewing it and muppets installing it incorrectly.

Was there all this commotion when we went from lead to copper?

 

[TBServices]

Magnetite in radiators is a product of corrosion, and the more oxygen there is in the water the faster the process will be - IF plastic pipe did allow air to pass, then that would explain excessive sludging. I've never heard that plastic will reduce the tendency for magnetite to form.

Right, hence the barrier. So when we're talking about excessive buildup here, we're on the assumption of using the incorrect pipe.


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[DirksPlumbing]

Right, hence the barrier. So when we're talking about excessive buildup here, we're on the assumption of using the incorrect pipe.

Well yes but no. The barrier is only hindering the process of oxygen intrusion. It is not a stop. If we are talking about excessive sludging in short period of times then most likely non barrier pipe has been used. But without inhibitor a plastic system has no chance but sludging. Hence my favorite MLCP as the metal layer is oxygen proof not only a barrier.
Although massive sludging can be caused by leaks as well because of adding constantly oxygen rich water to the system.

As for the copper mentioned in the process of sludging then that is explained by the fact that the different metal ions dissolved in the water do speed up the process of corrosion massively but once the oxygen has been used up then that stops. Meaning if you had a system that does not comprise anything but steel and plastic the process would be slower. But due to the oxygen intrusion still never stops. Just that would require a complete absence of other metals but the sort of steel used for the radiator. It actually could endanger SS heat exchangers as them would start rusting then just as normal steel.

So there is an easy rule: If it is open vented system use inhibitor, if it is a sealed system comprising plastic use inhibitor, if it is a sealed system comprising metal aka copper use inhibitor. The last theoretically does not need it that urgent but how do you make 100% sure that the integrity of the system never ever gets disturbed? As soon as the customer has to top up the system or the boiler comprises plastic fittings or..., well you need it.

But then again we should keep that quite as the volume of system cleans has dramatically reduced over the recent years and I have no other explanation than the use of inhibitor becoming more wide spread. At least for me.

As for the antibacterial feature you can use PVCC pipe as well as it even reduces buildup of lime scales. I had been told that PVCC would be preferred by NHS?

 

[petercj]

Look for the relevant British Standard markings on the pipe:-

John Guest Speedfit - The World Leader in Push-fit Fittings, Pipe and Plastic Plumbing Systems - PEX BARRIER PIPE IN COILS

 

[TBServices]

Good answer dirks!


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[petercj]

Good answer dirks!


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There is a lot of cobblers talked about the use of plastic in central heating systems - plastic has been widely used in the manufacture of vehicle radiators for the past 25 years without major problems - with water at 100c +.

O rings have been used in aero-engineering for decades - next time you take off in a plane spare a thought for the fact that your life depends on those O rings in the system holding up!

A Valliant staff engineer told me that most of the blockages he sees in heat exchangers can be linked to muck being downloaded from header tanks when the system is drained.

A mild steel container such as the average household radiator is going to corrode and produce some kind of debris, however, the process can be slowed down by using inhibitors. Copper and SS are a different matter - both are alloys, and so the quality of each will dictate how well they perform in use. Copper pipe in reasonable nick has been found in Roman ruins. Good quality SS is very resistant to corrosion, and I doubt that corrosion would ever be a problem with a SS heat exchanger unless a problem was caused by a chemical within the water - most metals don't like common-a-garden salt, including aluminium alloys, and poor quality SS can be affected by salt. However, water in a CH system is the same water that goes round and round, and so the content of such water is bound to be fairly stable. Limescale for example, requires fresh water to be constantly introduced and heated to produce a scale. Magnetite (as the name suggests) is magnetic, and so will generally stay in the radiator in which it is produced. The chemicals used to clean CH systems work because they lift magnetite into suspension, making it easier to flush out.

Whereas the problems caused by sludge and scale are unlikely to be all down to myth, the companies who make flushing and cleaning chemicals have a vested interest in exaggerating the problems. If a radiator is so full of sludge that it doesn't heat up as it should, then obviously it needs cleaning out.

For a CH system to become severely sludged, or for a heat exchanger to become blocked by scale, the process is going to require freshly oxygenated water, probably a lot more than can be passed by a plastic pipe, even if it hasn't got a barrier.

How many people on here can honestly say they always check the header tank for muck and debris before draining a system?

Much easier to say that a blocked heat exchanger can be traced to plastic pipe than admit that it's become blocked due to muck being introduced into the system from the header tank, or some other external source.

Whilst copper is usually the best choice, plastic pipe is another - much hated and defiled as it is by many people in the trade.

 

[DirksPlumbing]

There is a lot of cobblers talked about the use of plastic in central heating systems - plastic has been widely used in the manufacture of vehicle radiators for the past 25 years without major problems - with water at 100c +.

Much easier to say that a blocked heat exchanger can be traced to plastic pipe than admit that it's become blocked due to muck being introduced into the system from the header tank, or some other external source.

Whilst copper is usually the best choice, plastic pipe is another - much hated and defiled as it is by many people in the trade.

I am just struggling to explain all the sludged up sealed systems. Or the ones been build from scratch.

And I hope your car mechanic does not fill pure water into your cooling system. Even the use of tap water is to avoid unless there is an emergency and nothing else available.

Just as I hope that you would see the difference between algae etc. and magnetite. A magnet helps on that.

As for the planes, are you gonna go and service the boiler/pipe system at a similar frequency? Do your customers allow that to you?

 

[Tap dancer]

As a so-called "custard" (a term that I feel is derogatory to the people who pay you) I would always specify copper for any work I had done, and would avoid buying any house that was plumbed with plastic.

This goes back to very bad experiences with my 3rd house, which used plastic pipes.

PS They were grey plastic, but don't know what they were called.

 

[petercj]

I am just struggling to explain all the sludged up sealed systems. Or the ones been build from scratch.

And I hope your car mechanic does not fill pure water into your cooling system. Even the use of tap water is to avoid unless there is an emergency and nothing else available.

Just as I hope that you would see the difference between algae etc. and magnetite. A magnet helps on that.

As for the planes, are you gonna go and service the boiler/pipe system at a similar frequency? Do your customers allow that to you?

So how do you explain the conclusion that those sludged up systems are due to the use of plastic pipe?

The pressure inside a vented system is considerably greater than the 14 lbs per square inch on the outside of the pipework, so how does air get sucked in? If there was a vacuum inside the pipe and no barrier, then I could see how it might happen!

Accepting that copper is generally the better choice than plastic, I do believe plastic pipe gets made a scapegoat for all kinds of ills and mistakes made when fitting systems.

Due to an extension before I bought the property, a third of my home is done in plastic, and there have been no problems with it since the mistakes made by the plumber / GSR who fitted it were put right, i.e. using it right up to the boiler, not clipping as required, and muddling up flow and return - he connected the boiler up the wrong way around! It's not just DIY'ers that create problems when using plastic.

If someone on here asked about a leak in copper pipe, the general response would be: "well it sometimes happens", but if it was plastic there would be a queue of people claiming it was evidence that plastic is no good.

I do see the long-term security of the O rings as a potential problem - as I recall, the manufacturer's say they are good for 25 years, but what then? Some kind of sealer that can be left permanently in the system maybe. Sooner or later it's going to be a problem for someone to solve, that's for sure.

Probably only a matter of time before plastic radiators become the norm, so hang on to your headache tablets.

 

[Blumper]

...oh dear, we have bitten the hand that feeds us, a paying custard...!

 

[Doodlebug]

There is a lot of cobblers talked about the use of plastic in central heating systems - plastic has been widely used in the manufacture of vehicle radiators for the past 25 years without major problems - with water at 100c +.

O rings have been used in aero-engineering for decades - next time you take off in a plane spare a thought for the fact that your life depends on those O rings in the system holding up!

A Valliant staff engineer told me that most of the blockages he sees in heat exchangers can be linked to muck being downloaded from header tanks when the system is drained.

A mild steel container such as the average household radiator is going to corrode and produce some kind of debris, however, the process can be slowed down by using inhibitors. Copper and SS are a different matter - both are alloys, and so the quality of each will dictate how well they perform in use. Copper pipe in reasonable nick has been found in Roman ruins. Good quality SS is very resistant to corrosion, and I doubt that corrosion would ever be a problem with a SS heat exchanger unless a problem was caused by a chemical within the water - most metals don't like common-a-garden salt, including aluminium alloys, and poor quality SS can be affected by salt. However, water in a CH system is the same water that goes round and round, and so the content of such water is bound to be fairly stable. Limescale for example, requires fresh water to be constantly introduced and heated to produce a scale. Magnetite (as the name suggests) is magnetic, and so will generally stay in the radiator in which it is produced. The chemicals used to clean CH systems work because they lift magnetite into suspension, making it easier to flush out.

Whereas the problems caused by sludge and scale are unlikely to be all down to myth, the companies who make flushing and cleaning chemicals have a vested interest in exaggerating the problems. If a radiator is so full of sludge that it doesn't heat up as it should, then obviously it needs cleaning out.

For a CH system to become severely sludged, or for a heat exchanger to become blocked by scale, the process is going to require freshly oxygenated water, probably a lot more than can be passed by a plastic pipe, even if it hasn't got a barrier.

How many people on here can honestly say they always check the header tank for muck and debris before draining a system?

Much easier to say that a blocked heat exchanger can be traced to plastic pipe than admit that it's become blocked due to muck being introduced into the system from the header tank, or some other external source.

Whilst copper is usually the best choice, plastic pipe is another - much hated and defiled as it is by many people in the trade.

Can I ask, what do you do? What is the main role of your job? What are you? Are you an engineer? A doctor? What qualifications and experience have you got? How many sludged up blocked systems do you came across? Sorry for all the questions, just curious.


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[petercj]

Can I ask, what do you do? What is the main role of your job? What are you? Are you an engineer? A doctor? What qualifications and experience have you got? How many sludged up blocked systems do you came across? Sorry for all the questions, just curious.


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Attack the argument, not the person dear boy!

 

[Doodlebug]

Attack the argument, not the person dear boy!

Sorry, you've lost me there. Who's attacking who? Not sure where you got that from. I asked you a question.


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[Millsy 82]

I am not a big fan of plastic and the only time I have used it was when I was site bashing I will personally always choose copper. But most of the problems that I have come across with it have been installation faults ( or somebody undoing the fitting thinking their funny) I would have no problems with fitting plastic in my house but I would have to fit it same as with copper as alot of the time its not the material but the muppet fitting it.

As long as its all tested correctly ( the last lot I used was poly plumb and the rep told me to test it to 10 bar so that the grippers would dig into the pipe and hold it and never been called back to any of it that was also their way out of claims if the pipe didnt have the marks they wouldnt pay out) then I cant see a problem.

 

[Gray0689]

Plastic is great all new hoses should be done in it for rads all to manifolds no joints and no fittings

 

[Resolute]

Plastic is great all new hoses should be done in it for rads all to manifolds no joints and no fittings View attachment 7801

You'll be fitting plastic rads next!

 

[Gray0689]

Where in 2012
new houses should have total control the days of upstairs downstairs and hot water only are gone should be every room has separate temp controls

 

[Gray0689]

You'll be fitting plastic rads next!

If they where efficient you bet I would

 

[Doodlebug]

You'll be fitting plastic rads next!

I hope you leave your number with this customer. Lol


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[petercj]

Sorry, you've lost me there. Who's attacking who? Not sure where you got that from. I asked you a question.


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I’m a brain surgeon, and I read the posts on this forum between operations for R&R!

I can tell you why you and your colleagues at British Gas see so much sludge, it’s because whilst charging around £25 a month for looking after your customer’s central heating systems (Home Care) you completely ignore the water in the system, i.e. no checking and no topping up of the inhibitor.

Then when the system is sludged up you tell your customers that for a mere £599.00 BG will power-flush the sludge out, and then thereafter you will actually check the state of the water.

No doubt you tell them that all their plastic pipe-work needs replacing as well!

“Looking after your world” … Best advice = read the small print in the BG Home Care contract very, very, carefully.

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[Dannypipe]

You're not really a brain surgeon are you....? Surely you would have said neurosurgeon to sound more realistic.

 

[DirksPlumbing]

So how do you explain the conclusion that those sludged up systems are due to the use of plastic pipe?

Not my conclusion. If you use inhibitor and make sure there is enough present plastic does tend not to sludge up excessively either.

The pressure inside a vented system is considerably greater than the 14 lbs per square inch on the outside of the pipework, so how does air get sucked in?

Who talks about air getting sucked in? And forget about a plastic pipe wall it is mere a thick membrane. How do you guess gets hydrogen into expansion vessels even though the pressure is equal both sides? It simply has to do with the fact that nature is based on chaos so if there is a low concentration on one side and a high concentration on the other side it will try to level them out.

If there was a vacuum inside the pipe and no barrier, then I could see how it might happen!

Accepting that copper is generally the better choice than plastic, I do believe plastic pipe gets made a scapegoat for all kinds of ills and mistakes made when fitting systems.

Agreed.