About 20 years ago a number of us bought in-line gizmos for treating water from a guy we knew and wanted to give a bit of work.
The things were supposed to consist of different metals, producing an electric cell, although he had other types.
Our area had very hard water.
All of us noticed a dramatic improvement, central heating heat exchangers not clogging up etc, and one guy’s pipe joints decalcified and started leaking (he was impressed rather than annoyed).
I heard something from a water engineer (?) at the time, that differing gizmos worked in different areas, but nobody really knew why.
We just put them in to help out a guy, we didn’t really care whether they improved things and would have ripped them out if they had made things worse. As it was we were impressed - it could have been a coincidence with the Water Co changing its source of abstraction. Possible, but unlikely.
My view is test the things out, or rather get one or two people to test them.
Sometimes things can be both a scam and effective.
When the Daily Mirror ran a story about these phony magnets a few weeks ago its online edition was swamped by people praising the product and saying that it was the best thing since sliced-bread. It turned out that all these people were distributors of these products posing as satisfied customers.
The UK Advertising Standards Authority also found against these products and the phoney claims being made about them :- ASA
If these things worked at all, they would be used widely in the generating and heating industries.
Water treatment chemicals cost money, but compromised pipework costs very much more, if they worked you could reduce maintenance, increase reliability, reduce the number of redundant systems, maintain efficiency.
Since industry does not employ these devices, where even a couple of percent improvements can amount to large sums of money, you can draw your own conclusions.
Not necessarily uncritical. I installed the thing expecting it not to work, as did my friends. From my point of view not having to get a decalx or a replacement calorifier every year was a pleasant surprize.
Personally I suspect that the type we used only works in certain areas, which is what I heard from an independent source.
I doubt that feeding my boiler Obecalp pills would have had beneficial results
