[Bored chemist]

I was also big skeptic on this but the explanation that the magnetic field reduces the propensity to precipitate out, maybe somehow altering the way the crystals start to stack together, sounds quite plausible to me. This is lime scale I'm talking about, not Fe oxide

Well, it doesn't sound convincing to me.
Limescale isn't magnetic, nor are the ions from which it's made.

[wolfekeeper]

Everything is slightly magnetic, it's not inconceivable, but it's not been proven to work.

[Bored chemist]

I was also big skeptic on this but the explanation that the magnetic field reduces the propensity to precipitate out, maybe somehow altering the way the crystals start to stack together, sounds quite plausible to me. This is lime scale I'm talking about, not Fe oxide

Well, it doesn't sound convincing to me.
Limescale isn't magnetic, nor are the ions from which it's made.

Everything is slightly magnetic, it's not inconceivable, but it's not been proven to work.

No, Not everything is magnetic. Some things are attracted to magnets, some- like water are repelled.
However it's important to remember that the effect of a magnetic field on most atoms or ions is tiny. Even the huge fields used in MRI machines only slightly  affect the protons  they image. The thermal motion knocks them back into random motion rather quickly.
The calcium ions typical of lime-scale are even more weakly affected by magnetic fields than the protons.
And, of course, these "magic" pipe-cleaners are not using huge superconducting magnets to generate a field like MRI scanners.
There si absolutely no way these things can work on lime-scale.

[wolfekeeper]

No, everything is magnetic, paramagnetic, diamagnetic, ferromagnetic etc. etc. etc.

So the question probably isn't really even whether it affects scaling, the question is whether it does it to a noticeable degree. It might even conceivably make it worse.

Most of the evidence seems to say it doesn't affect it measurably though.

[pippystardust]

I cant see how it could possibly work   If it did then surely it would only provide a limescale free band around the pipe where the magnet is...this theory was probably started by dippy hippies who think that crystals actually DO stuff that influence your life /health/happiness etc    IE complete crap !

[wolfekeeper]

Yes, I would think that as soon as it leaves the magnetic field that brownian motion and so forth would derange any alignment at all; it would decay ever-so rapidly.

I did read somewhere that somebody was getting a positive result, but that was later established to be due to them accidentally adding ions to the water, and the ions were changing the structure-they'd plumbed the gadget in wrongly and it was contaminating the water.

[acecharly]

Please nobody throw anything at me...but im a plumber/GasSafe heating engineer and I fit a device called a MagnaClean, it is fitted to the heating system and not the domestic (drinking/cleaning etc) water. Its basically a pot that is cut into the heating flow pipe with a magnet in its centre. This collects debris/sludge from your radiators and is quite effective. I never install magnets on the domestic side of a water system though. I have seen them before and id say if they do  work it may be down to the magnet lining up the positive and negative ions up so as they dont attract one another although how slow the water would have to run or strong the magnet would have to be for this to be effective im unsure.

[daveshorts]

Nothing wrong with using a magnet to collect ferrous metals fragments and associated sludge, that would damage a pump, or gum up your system, that makes sense... this is very different from using it to 'soften water'.

[SeanB]

I use magnetic plugs to remove ferrous debris from oil in pumps and compressors, as they then are not going to cause any further damage. Generally I get a light coating every few months of operation, pretty much normal, caused by wear of the cast iron bores.

[Tunsarod]

I was sceptical about this; 45 years making a living in the electromagnetic and electronics world and I figured it was a load of codswallop. In the last three years I have been repairing a variety of laundry and kitchen equipment in a hard water area and without a doubt, where these things are fitted, be they electro-magetic or just magnets, they make a difference. As was said ealier, you still get limescale but it's softer and easy to remove. It must be something to do with the calcium molecules lining up with each other. The same argument is applied to the idea of magnets applied to fuel lines though I do not have any experience of that application.   

[Bored chemist]

Data isn't the plural of anecdote.

[magneto]

if you're 'bored' you might consider finding another field to consider for awhile.  in that state not a lot of inspired awareness happening.  but inspiration doesn't exist anyway, right?

[Peter]

The pipe magnets DO work.

I've been fitting them for many years.

They don't prevent scale getting through (obviously but the scale doesn't stick anywhere near as much to the pipework.

The other thing is that if you fit the magnet to pipework which is already scaled-up, a lot of the scale comes off the pipe and blocks stuff downstream So you find e.g. shower heads getting bunged up with scale and having to be rinsed out, but this settles down after a few months.

[ladyfilosopher]

This has been one of the most interesting discussions I have read for a while. (who's the geek, now?) I am changing my boiler and needed to know about this very subject about how lime could be affected by magnets or in any case how the lime could be jostled and not allowed to attach itself to the pipes and kettle. The Magnaclean commenter confirmed what a plumber giving me a quote for installation had told me. I had thought that the magnaclean's magnetic filter was also for the descaling. Now I am convinced that I will install both the magnatised water conditioner and the magnaclean, one for the household reality and the other for the boiler and radiators. I appreciated the pros and cons presented in the discussion. Fabulous how you all kept on topic and furnished a non chemical engineeer with enough information to make a decision. Thanx

[blackswann]

I am sales rep for a  heating installation company and see a lot of boilers etc in homes  recently  i called to a 80 year old ex engineer who fitted a magnet to the water pipe  he had probléms with limescale he said overa period of a year it removed all the limescale from his system include the water cistern in the wc etc . i am now going to do the same at  home have

[Jan]

Looked up this site as I had just remarked to my husband that our gas kettle no longer has limescale in it after fitting a magnet to the incoming water supply pipe - it works!

[Tim]

I was wondering whether the effect of these magnets on limescale has nothing to do with any effect on the copper pipes but rather something to do with the composition of the limescale itself. Looking it up on Wikipedia (not the world's most reliable source I know but also not as unreliable on science questions as some would think) I find that there are at least three limescale types that contain iron (Wustite, Hametite and Magnetite - FeO, Fe2O3 & Fe3O4) so maybe the 'works in some areas but not others' could be to do with the type of limescale minerals found in those areas, in the iron content of the water. Just a thought.

Also I'm fairly sure that at some level magnetism can affect non-ferrous materials. Like inducing an electromagnetic field - like this:

- so who's to say that it can't have an affect on the copper pipe or the calcium element of Limescale.

[PeterFW]

Fascinating debate. Surely this could be settled by means of a simple experiment? Run two lines of hard tap water, subject one to a magnetic field and leave the other alone. Test the outgoing water for conventional hardness, and filter and run crystallography tests for the forms of  carbonate in suspension. At the same time the test could check for deposition over a longer timescale. Mass balance test on Ca to check that its all accounted for. Sort the question out once and for all! Anyone got a lab?

[jonnyleonard]

I have personally used this method for stopping the build up of lime-scale for over 25 years, in France, America and now in England, the kits come with 2 double magnets which wrap around the pipe you fit them about 7 cms apart so the magnets are repelling, this changes the properties of the lime-scale particles and it then DOES NOT build up on elements, inside hot water pies etc. The prof who you sent it too for comment didnt even notice that the guy who prompted the discussion said  REMOVE how could it if it wasnt a filter??? 

[AndyJ]

Perhaps bored chemist would not be bored if he stopped theorising and carried out  an experiment or two