ᐅ Is a Heating Water Softening Unit Worthwhile?

Hello everyone,

I am having a house built, and currently the plumbers are installing the pipes. I have received a quote from them for a Hydraulic Energy Station (HES) for around €500.

The house will have underfloor heating and a heat pump. Is an HES useful in this case? Especially since we have relatively soft water here anyway.

How often does underfloor heating need to be refilled? Is it possible to do this yourself? You can buy demineralized water compliant with VDI 2035 standards online.

This question concerns only the heating system, not the general domestic water supply.

Why does the heating technician want to install the HES?

baddy schrieb:
How often does a underfloor heating system need to be refilled?

Normally, it doesn't need to be refilled at all (in the current house, it was last done 3.5 years ago during commissioning; in the previous house, never).

baddy schrieb:
You can buy demineralized water compliant with VDI 2035 online.

And how do you get that into the heating system?

He wants to install it because our drinking water does not comply with VDI standards.
With a standard garden pump? That's what I had in mind, but does that actually work?!
I don’t see the point in installing a system for 500€ to use it once every five years, plus I’d still have to buy the cartridges.
Or alternatively, if it needs refilling, call the plumber.

baddy schrieb:
He wants to install it because our drinking water does not comply with VDI standards.

Then he has formally taken the correct approach. Although it can also be said that the initial filling should be done with “proper” water and you can turn to a professional if needed (whether you actually do that is another matter). That would also be completely fine. The HES system is only needed for the filling—if filling is necessary at all.

baddy schrieb:
Using a standard garden pump? That’s how I imagined it, but does that really work?!

Probably not—LOL

baddy schrieb:
I don’t see any sense in having a station installed for 500€

A very important point. Warranty. If you simply fill it with tap water—when needed—the installer might void the warranty due to misuse by the homeowner. But after five years in any case, there is no warranty anymore—except if there are extensions, for example for heat pumps, when service contracts are signed, etc.—however, that is then an additional service on the individual device from the manufacturer, not the heating installer.

What exactly are your water quality values?

Too bad, I thought you could fill it like with a gas heating system 😀. The hardness here is 9 dH, conductivity 291, pH 7.8

baddy schrieb:
thought you could fill it like with a gas heating system

Let’s put it this way: a heating system is a heating system—regardless of the energy source. So yes, in practice, oil, gas, heat pump, pellets, and others can all be “simply” filled like that or follow the formally correct procedure (with a water treatment system or through a heating technician).

In practice, I actually only know owners (among friends/acquaintances) who connect the hose to the pipeline and top up as needed. The only exception is with extremely hard water.

9°dH is already relatively soft, and I would personally reject a water treatment system.