Re: Central Heating - Mixed iron and copper pipes

[BigWallop]

We are in the process of buying a house in which new rads and boiler, and bits

> of copper pipe, have been grafted onto an old iron pipe system. The surveyor > says we might get away with it using inhibitors for a year or so, but we really > ought to have all the iron pipe removed and replaced with copper, so almost a > complete repiping job on the CH, in a large house. > > Does anyone know just how big an issue this is? If we are careful to keep the > system well inhibited how big a potential problem with corrosion would we have, > and would it really be reduced that much by getting rid of the iron pipe? > > Any views, or references to sources I could look at please? > > Peter >

Forwarding to uk.d-i-y, to get a better response.

[Andrew Gabriel]

All current heating systems are a mixture of iron and copper too. I wonder what your surveyor thinks radiators are made of? ;-)

Unless there's some reason other than just iron pipework (such as lots of leaks visible), I wouldn't worry about it. Yes, you should make sure the system has inhibitor in it, just as with any heating system. If I was refilling an old system, I might be temped to flush it with just plain water, incase any of the flushing agents turn out to unblock micro leaks which had sealed themselves.

[BigWallop]

Sorry folks, but I've cross posted this question to get a better response from more knowledgeable people. :-))

[Andy Hall]

I'd always been given to understand that provided that you interface between the two using brass fittings that the electrolytic/galvanic action is substantially reduced anyway, and with inhibitor corrosion is pretty much eliminated.

.andy

To email, substitute .nospam with .gl

[IMM]

Surveyors are good at concrete, not much else.

A system flushing agent should do no harm. Powerflushing creates all the leaks.

[Peter Gray]

Thanks all for your responses, and for copying my query to a more sensible place!

I've got a Corgi going in next week to take a look. Speaking to him on the phone this afternoon he gave an explanation of the problem I found more convincing than my surveyor's! He said the real concern is around the joints between the copper and iron. If they haven't been done well then local corrosion can lead to them leaking. The impression he gave me was that if they had been done well it was probably OK, but we are going to talk about it more next week once he's had a look.

Peter

[Martin]

Bigger, yes, but "more sensible"? Shome mishtake, shurely... :-)

-- Martin

[remove barrier to reply]

[N. Thornton]

Surveyors will want to mention anything that has any possibility of causing problems later on, as they can be got if they dont. They leave you the buyer to decide how big an issue these things are - from irrelevant to major.

Iron piping is more prone to leaks and splits than copper, due to corrosion and some other issues. Thus the odds of a leak are greater, but if it works OK I cant see any sense in ripping it out. It might spring a leak in 30 years and need fixing, who knows.

Lets take a guess and say theres a small chance of a need to replace the pipes one day, but probably not.

Regards, NT