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https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl DIY Forum >> Plumbing Questions >> Copper pipework https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl?num=1273491139 Message started by MrD on May 10^th, 2010, 12:32pm

Title: Copper pipework
Post by MrD on May 10^th, 2010, 12:32pm

I have re-run most of the central heating pipes in a friends house and although all pipes have been cut to length and have the fittings all in situ, I have yet to solder them. The combi boiler is not due to go in until the end of the summer.
So my question is: Can I solder them now and let the boiler installer flush the pipes out then OR will I have to solder them together nearer the time (I know the latter is best but I want to pressure test my runs)

Any advice greatly appreciated

Mr D

Title: Re: Copper pipework
Post by CWatters on May 10^th, 2010, 8:52pm

If you are going to pressure test your bit why can't you flush it as well?

I'm not a plumber but in my experience copper is a lot easier to solder if you thoroughly clean the joints (pipe and fitting) with wire wool, then immediately coat with flux, assemble and solder them. If you don't clean the joints or leave the copper to oxidise again it will be a lot harder.

Murphy's law also says you will forget to solder one if you do them later.

Title: Re: Copper pipework
Post by thescruff on May 11^th, 2010, 1:23am

No reason why you can't complete the job, solder, test and flush the pipes. In fact it's recommended.

You should cap any open end to keep the creepy crawlies out. Speedfit caps will do for that as you can take them off for reuse.

Remember if you're doing any gas, it must be exposed for the engineer to inspect and test.

Title: Re: Copper pipework
Post by MrD on May 11^th, 2010, 6:04pm

Sorry if I wasn't clear on my post but I know how to solder. My concern was on the flux eating away at the pipework. Would flushing the system via a mains pressure surfice? Obviously I won't be able to add any flushing chemicals.

Thanks again

Mr D

Title: Re: Copper pipework
Post by thescruff on May 12^th, 2010, 1:30am

wrote on May 11^th, 2010, 6:04pm:

Sorry if I wasn't clear on my post but I know how to solder. My concern was on the flux eating away at the pipework. Would flushing the system via a mains pressure suffice? Obviously I won't be able to add any flushing chemicals.

Thanks again

Mr D

I don't think anyone suggested you didn't, but if you know how to solder, you will apply flux to the pipe only, and as a result very little flux will get in the pipe.

When you have completed the pipework you should water pressure test it, after which you can drain down and flush with mains water, drain down and cap any open ends.

Title: Re: Copper pipework
Post by MrD on May 12^th, 2010, 4:59pm

Thanks Scruff thats all I wanted to know.

Thanks CW for your input too
:)