Underfloor heating grooving - experiences?

Today we had the first mentioned appointment and the gentleman advised against milling. After taking over the house, we will meet again and then the thickness of the screed will be checked or drilled in detail to determine the further procedure.

By the way, he would recommend the Viessmann Vitodens 300 or 333. I had already come across the system before, but I would be interested in your advice regarding the hot water tank. We are a family of four (2 kids - 2 years & 6 months). The heating installer mentioned 120l-160l. Would that size range be suitable for us? What capacity would you recommend?

Hello Witalja,

and how are things looking for you now?!

I also have big projects coming up like the installation of underfloor heating + hot water preparation.
There are two of us, and I got myself a 300L hot water tank. Slightly oversized. But future-proof ;D

In principle, nothing further has happened yet. The second HB recommended Brötje EcoCondens Kompakt BBK 22F to me (with hot water storage of about 100l). Well, it may be future-proof, but as far as I had read, it is also inefficient. But 100l seems a bit too small to me. However, I have not really had an extensive exchange yet. Something should move forward on the matter again in three to four weeks. I have now abandoned the milling-in for myself.

When does it start?

So with 100l it will be difficult with the bathtub, right? Although with some luck you can fill a 160l tub, since the temperature in the storage is higher than in the tub, but after that all the warm water is gone. Or if several people want to shower one after another. On the other hand, the question is up to what power the system reaches as a maximum. About 18kW would be enough for an instantaneous water heater for showering.

Okay. If your heating system has the necessary capacity for it, then I would choose a slightly larger hot water tank (than 100L). Saves later retrofitting / renovation work and costs. Then you are on the safe side. The construction site at my place starts in about 2 weeks. I will have the underfloor heating installed exactly as the floor is now. I will not remove the screed. So the floor will be raised by about 9cm. Insulation underneath, underfloor heating on top, screed on top, done. (The prerequisite for this is that the structural engineering must support it.) Advantage: saves time and hard work. Disadvantage: I have to raise new door frames and the door passage by about 9 cm.

So I will definitely choose a larger storage. I think 160l is a good choice.
The Brötje Kompakt was rated at 22kw.

So similar to us.

I haven't even considered that option yet. Even though I tend towards the more unpleasant variant. At the beginning we will also be a bit under time pressure because we will go on vacation a little over three weeks after taking over the house (we had booked it before the purchase). During that time, I would accordingly like to have the screed laid. Whether that will actually work out is still up in the air.
Feel free to update here regularly on how you are progressing and whether any complications occur.