Heat pump is not compatible with a water-bearing fireplace

we never had it on :)

Mathematically, however, it was required. It hangs behind the door on the wall and does not bother anyone. It also didn’t cost a fortune.

We received over €500 reimbursed from the main contractor. I would have to look up what was added up there. With the chaotic crew, I wouldn’t be surprised if the towel radiator still appears in the heating load calculation.

Hi, Is the radiator supplied from the same mixing circuit as the underfloor heating, or does it have its own mixing circuit?

Yes, it has the same mixing circuit.

I have also heard about varicose veins. Brian's mother already said: "I heard about germs that have antennae and bite," which she surely meant the underfloor heating. And with that, we have already identified the most trustworthy source for this suspicion [i(denti)fiziert].

We have four electric towel radiators. None of them was turned on more than once - but every year a different one corrodes from the inside (the first after two years, brand manufacturer) and then the floor had to be cleaned for hours, and of course a new radiator had to be purchased and installed. Of course, everything was covered by warranty, but it was still annoying. If I leave one thing out in the next house, then it will be that. Matter of taste.

OK, that's just how it is when you first heat water with loss and then pump it through the screed. But it also works without the water, and the heat pump only heats in the room where it is necessary.

Now I get it. You have an air-to-air heat pump. I've never read anything good about Proxon and company. But it doesn't matter as long as you are satisfied yourself. For example, we have 21.5 degrees everywhere during the heating period. Currently less on the north side because we haven't started heating yet and it's not necessary at the moment.

Now I got it. You have an air-to-air heat pump.

No.
The air-to-air heat pump does not produce radiant heat.

Yes, it has the same mixing circuit.

Then you either heat with unnecessarily high system temperatures, which is neither beneficial for the efficiency nor the operating behavior of the heat pump, or the towel radiator barely contributes to the heating load. Heating with high system temperatures means strong throttling of the underfloor heating. This results in only a small volume flow in the heating circuit. Heat pumps generally operate with high volume flow. If the volume flow is too low, the heat pump cannot release the heat and must shut down. Even with a separation buffer like yours, this problem can only be slightly mitigated. Therefore, the recommendation is either an electric towel radiator or wall heating. The room temperatures are then not controlled via the ERR, which can only switch on and off, but via the flow at the heating circuit distributor. Ideally, the ERR should remain open almost permanently in almost all rooms to guarantee sufficient volume flow. They can be used in the bedroom. It is best to deactivate the ERRs that are not needed, so that no one can accidentally cut the volume flow and electricity is saved. The room temperature is adjusted by means of the flow of the heating circuits! This should be calculated in advance (hydraulic balancing). In the first years, optimization is then necessary (thermal balancing). A smart control is not required for this, only a thermometer and some time.