Boiler Cleaning

I am changing some fittings on a copper water tube boiler and when looking inside it looks quite grubby - almost like soot on the main firetube?

I was considering filling with a cleaning solution but wasn't sure what to use.

What is generally recommended?

Alan

Greetings Alan, I would suggest Citric Acid crystals for a copper boiler, flushed into the boiler with hot water through a safety valve bush, aggitated as much as practical, depending on size, allowed to cool, and well flushed with cold water.

About a heaped teaspoonful for a largest 3.5 in boiler, up to a heaped tablespoon for a large 7 1/4 gauge boiler.

Citric acid is safe to use & will not damage boiler fittings. Some people use drain cleaner etc, but its strong acid content can do damage, as well as being dangerous to use hot.

The residue can be flushed down the drain.

try a home brew shop for bulk supplies.

Regards

Leighsteamer

Beware! Somewhere I have read a discussion on various boiler cleaning chemicals where they warn that Sulphuric Acid causes the hard chalky deposits to undergo a chemical change, resulting in the deposit becoming even harder and more difficult to remove and resistant to further use of even very strong solutions of SP. Most toilet/drain cleaners contain either SP or Caustic Soda.

I think it would be very wise to go for the more gentle Citric Acid and see what results.

Rgds

JC

Sorry, I typed SP in error - should have been SA

JC

Thanks people, I always use citric acid for the kettle but it was the black appearance which was confusing me! However having another look although it appears black (but not sooty like soot) I cant actually see any 'scale' but I can't actually see the area where the main heating goes on so I will give it a workout with the CA

The boiler in question is a marine boiler which measures about 10 inches long by 6 inch diameter and going a bit off topic I would like to paint the ends (which aren't lagged) matt black any recommendations?

Alan

Hi Alan, what you are seeing is probably a thin layer of copper oxide, a black oxide of copper which forms when the copper in your boiler becomes warm. The same thing happen on the outside with age, the copper turns black.

Regards

leighsteamer

To paint the boiler ends, theres paint you can get for painting barbecues, it comes in a rattle can. Nice mat black, until it gets over heated, then it goes gray. Ian S C