Electric water heater, limescale and the magnesium anode

If you live in an area where the water is hard… you better know this things 😀 Limescale WILL be your biggest nightmare, and proper maintenance of your hot water producing devices is going to be crucial. You may not be interested to clean and remove the limescale from your own water heater, but you will know to call somebody to do it. (Unless it´s to expensive and it´s actually cheaper to just replace the whole damn thing #savetheplanet or wtf? – will get back to this later )

In 2016 December we installed a brand new, 80liter electric water heater. Shortly less than a year later I had the feeling that the heater was running way to much. We have differentiated electricity, meaning we pay less for the electricity used at night, (when the general demand is lower) so our water heater was set to run overnight. But because I was working quite a lot for many nights, after a while I had the feeling that the heater is running “all night”. I wasn’t entirely sure, just a hunch that bugged me. Hence we decided to take it apart i 2017, end of November.

I remembered, that my dad many years prior this explained to me how limescale can “grow” on the heating element, so I suggested my husband to check it. He was a bit in doubt, but agreed. We had not to much idea how to do it, but since there were screws in the heater bottom area… it was not that difficult.

First step for us was to turn off the water heater a day before, and use up the hot water.

Second step was to turn off the main water tap, and empty the whole system.

Third step is to remove the pipes and than take off the water heater from the wall and open it up.

One year of running:

I have to say, we were truly shocked. The heating element was full with encrusted hardened limescale, no wonder it had to work overtime to heat up the water! The anode (not visible in the pictures) still had “juice” on it.

The clean up was fairly easy. Removed as much limescale from the heating element that I could, and carefully I soaked in a cut off 2 liter water bottle with a mix of hot water and vinegar, let it stay like that overnight. Before we installed it back was again shiny and almost looking like brand new.

To FIX this issue, there is ONLY one thing you can trully do: install a water softening system. It’s not a cheap solution, and also requires space and maintenance.

We opted for a poly-phosphate crystals dosificator, very cheap and easy solution, basically a little “cup” with crystals in it and the water passes trough it. This is NOT WATER SOFTENING, it’s called “Water Conditioning” (and it won’t remove anything from the water) and the theory behind it is the following:

As untreated water passes through the water filter descaler, a small amount of poly-phosphate dissolves very slowly in the water stream and changes how the calcium and iron react in the water.


2 years after the first clean up:

For some totally unknown reason, we forgot to do the “one year after”. But we did the 2 year after, and this is what we noticed:

  • the limescale is present, although it seems less for the 2 year period of time, compared with the 1 year amount.
  • it was not so badly tied to the heating element, was falling off much easier.
  • still needs overnight soaking
  • the anode – which usually has a warranty of 2-3 years was almost completely “eaten up”. this is NORMAL and to be expected, even the alternative name “alternative name of sacrificial anode” suggests the role of being “chewed” by stray currents in the water. If there is no anode installed in a water heater, the stray current will “find a way” and generally the result is a leak somewhere in the body of the water heater.

The Magnesium anode

This is a small Magnesium anode, probably from a smaller water heater. It was the ONLY one available.

You would think people are more aware of this things, how they work, how can it be changed, especially here where the water is extra hard, where the most used water heating system is this. But to my utmost surprise, even SOME people working in plumbing and specialized hardware store were not aware of the existence of this things. I completely understand if most housewife don´t know what´s happening inside a water heater, but I would expect a store clerk to have at least the faint idea what they are how they work and on which shelve they keep them.

Store one person one was looking at us like we asked ice cream in the meat section. No, I have no idea what you are looking for. Luckily there was a brighter guy there, who joined us and quickly was able to bring out one. It was not for the right type of screw, but at least HE knew what the f.ck we were searching for.

He sent us to a different store, not to far away, where to my joy and happyness a lovely young woman greeted us. We explained her what we need, and it took her about 30 seconds… to go to the shelve, and bring out the little anode. Without any hesitation…

The thing was good, in terms it was the same screw size, just a bit smaller. For temporary replacement is better to have it, like not have it at all.

In meantime, we can now put together the water heater and find an ONLINE source to order the right size, because changing it won´t require us removing the water heater form the wall.

Some conclusions:

  • if you live i n a place with very hard water, you need to take the maintenance of your water appliances very seriously
  • adding a poly-phosphate “filter” will help at some degree, but it´s not a magical solution to the problem
  • everybody talks about “saving the planet” but generally NOBODY really cares to have small, consumable parts easily available
  • if my dad would not have told me about this things, we would never opened the water heater in the first place, and would probably ended up buying one in short perid of time after the warranty is expired due to some leak produced by the missing less than 10 euro passive part.
  • the water heater companies don´t give a crap about the environment (no surprise there) or to produce any replaceable passive part according to the same standard. I mean… I completely understand to need different length for the 30l, 50l, 80l, 100l water tank, but still can´t understand why each brand has to use different type of screws – making it incompatible between them (rhetorical question, I do understand) Because if we were “average” consumers, who have no clue, would have looked for a replacement “magnesium anode for Feroli”. And guess what, they are not so easy to find, and not everybody knows that the same type of “magnesium anode” will work from any other brand IF the screw at the end of it will fit our tanks other screw.
  • just quietly wondering how many times completely good, already produced devices are thrown out due to bad maintenance
  • also quietly wondering what % of parts are thrown out… because they are never used up and they are incompatible with any other brand´s device
  • In our case, I also wonder how much a generally simple task of changing the magnesium anode or cleaning up the water tank would cost if we were in the position to “call the expert”.

A final note 🙂

My dad used to tell me: lucky for those who have no idea what´s happening in the pipes. He told me this when he fixed the water pipe in his sister´s house, who had a nervous breakdown seeing the junk and dirt getting out from the old rusty pipes she had.

And as you can see from the pictures… we also had quite a lot of shit. Most of it is limescale, but we also have some sand. When there is very heavy rain, we often have muddy water for a short period of time.

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