ᐅ Desalination of Heating Circuit Water in Single-Family Homes with Gas Boilers – Necessary or Just a Sales Gimmick?

I live in a detached house with 150 sqm (1,615 sq ft) of living space, built in 2016, with KFW70 energy standard. Heating is provided by a gas condensing boiler; all rooms have underfloor heating.
During the last maintenance of the heating system, the technician recommended installing a water demineralization unit for the heating circuit.

Is this advisable or necessary?
What costs can be expected for installation and ongoing maintenance/refilling of the demineralization cartridge?

I have found very little information on this topic online. I would appreciate any opinions and experiences.

In 2014, our heating system was replaced, and the company recommended installing a water softener for the heating system. We had one installed for the entire house, and it works great for the tenants now. None of the devices get scaled anymore, and there are no more limescale stains. It’s definitely worth it. Salt tablets come in 25 kg (55 lb) bags and cost about 10 euros at the hardware store. We use around two bags per year.

Uh... call me a nitpicker if you want, but something seems off to me here:

After the heating system maintenance, the technician recommends a water softening system for the HEATING? Personally, I would at most change the water and install a filter at the refill connection. If that’s what he means: yes, I agree—I’d have to check what it’s called in our case, but nowadays it’s basically standard. Calling it a "water softening system" sounds a bit grandiose...

@Nida35a: On the other hand, I think you’re referring to a DESCALING SYSTEM—and that’s quite a philosophical issue. Something like that wouldn’t be allowed in my house, for example—partly because I drink water straight from the tap and therefore don’t want any salt in it...

So, I checked it out myself:

Search online for resideo – you’ll find an NK300SE-VE-1/2A. It’s a refill unit with a full deionization cartridge – that’s how it’s installed in our basement, directly fitted during the installation of the new system.

You can buy it online starting at around 410 euros.

It’s basically straightforward – water connection on one side, heating system connection on the other – done. I would have it installed by the heating engineer and book a flushing service at the same time – after almost 10 years, that can’t hurt...

Running costs? Negligible. This unit is only used for refilling, so it lasts a long time. Ours is now two years old and still almost fully operational.

Odyssee77 schrieb:

During the last maintenance of the heating system, the heating technician recommended installing a water desalination system for the heating circuit.

Reason for this? That is my number one question. If there is a good reason, only then should I consider what and how to do it.