underfloor heating problems

[Norcon]

Rothenberger-Rolot S2 are the best brazing rods available.
Cu - 92.8%
P - 6.3.

About £40 quid per kilo.

Silver can be added which of course increases the price and lowers the skill required to use them.

 

[flowboy]

Thanks for the tip.
I've done a fair bit of brazing to steel when I had a nice little oxy torch set up but they stopped supplying those oxy cyls a few years back. Silver I've used on m/c fuel tank repairs but not much else. Actually I think it was silver recommended for solar not braze. Possibly because of ease of use.
What torch do you use?

 

[Norcon]

I've got boc kit.

 

[Norcon]

Well I stripped my gauges down and they cleaned up a bit but really replacement is the only option & as I said, put a filter in as well.

With all this phosphorus stuff etc e're getting off the thread here but... Re. brazing v's soft solder, I read somewhere that in some solar installs' the system can reputedly get hot enough to soften the solder = loose joints. Brazing is recommended in those cases.
I am intrigued in the "no black sludge in France" & the common use of copper brazing there. Is that your actual experience?
Acid flux is likely a major contributor to bad corrosion in our systems; we are supposed to flush it all out before commissioning & not blather it on excessively to start with!

A good insight here....
http://www.ukplumbersforums.co.uk/plumbing-forum/4045-plumbing-france-part-1-a.html

 

[Onetap]

Thanks for the tip.
I've done a fair bit of brazing to steel when I had a nice little oxy torch set up but they stopped supplying those oxy cyls a few years back. Silver I've used on m/c fuel tank repairs but not much else. Actually I think it was silver recommended for solar not braze. Possibly because of ease of use.
What torch do you use?

It wasn't intended as a tip, FB. Soft soldering is perfectly adequate. I've never yet seen a properly soldered joint that had leaked or come undone.

It was intended more as a note of caution about getting acidic flux residues into a system. The active flux saves the installer time, but will cause problems in years to come if not flushed out and neutralized.

Brazing causes more discolouration and distortion of the joint.

I once had a holiday job bench brazing water heaters using copper/phosphorus rods. No flux needed and quite easy once you'd got the hang of it.