Over Fluxing on Central Heating fittings

[Coaster]

hello,
Recently, a friend of mine had an acquaintance fit a new radiator with about 6 metres of pipe and 12 soldered elbows. I had noticed that the person fitting it was scooping way.. WAY!!! too much flux on the pipes.

Later, I was asked to fix his cockups..

I noticed globules of flux on the outside surfaces which I cleaned off.

He didn't do a very good job fitting the pipes either, and ended up cutting and fitting new sections on pipe.

The main problem is, when I cut the pipe to re-fit an elbow, I noticed the pollock had used so much flux, there were green trail marks inside the pipe, running abour 3 or 4 inches down.

bearing in mind he fitted 12 elbows..
I've added Fernox F3 to the system and planniong on keeping it in for the week.

Should I flush out in a week and add second dose of F3.?

Any comments would be helpful in correcting the good hearted eeejot doing "a favour"

 

[Whitespirit66]

Once with F3 should be OK. Flux is acidic, and you are right to be worried about large amounts of it in a ch system. However, the water in the system will go some way to neutralising the acidity. A plain water flush after the F3 will be enough, before refilling again and adding Corrosion inhibitor.

Did he wipe the flux from the outside of the joints. If there are discoloured areas on the fittings, wipe over with a damp rag.

Plenty of elbows. Suppose the other bloke didn't have a bender?

 

[Coaster]

He's Supposed to be a plumber but i don't think so. The only pipe benders he's got is his knees. No he didn't wipe the pipes. I did it after he left when i saw the big flux globules.

 

[neds]

As my old Tutor used to say, flux was the boiler killer!

 

[doitall]

Big problem if you have any stainless steel in the system like a cylinder or boiler.