Set controlled residential ventilation KFW 70 with underfloor heating

Thanks to you! In December, the two of us had about 120m³ with roughly the same values.

We also use night setback, even though the entire house has underfloor heating. The temperatures don't really drop much overnight. Whether you actually save money directly through the setback is certainly doubtful, but I have another positive effect from it. At these mild temperatures around 0°C, my gas heater cannot modulate down far enough and starts cycling. This is certainly not as inefficient with a gas condensing boiler as it is with a heat pump, but it still probably costs a few percent. This way, the heater can heat properly for about 30-45 minutes in the morning instead of cycling throughout the night. The condensing effect is thus certainly better utilized.

So, for the record.

The stove is here and running.
It fits exactly as we had imagined.
Heating during the day with the stove, all doors open and the whole house warms up nicely, perfect.
The gas meter has only moved minimally.

It looked different at night:
From about 11 PM to 9 AM, approximately 2 kW were wasted.
I think this is because during the day, as the thermostat notices it's warm enough and turns off the underfloor heating, the floor hasn't warmed up sufficiently yet.

Well, let's wait and see...

I will now do another test:
All the time we had 2 time windows: 5-7 and 14-21, at 22 degrees and 18 degrees during the setback.

I will now switch to one time window from 5 am to 9 pm, also at 22 and 18 degrees.

I will also run this for 30 days and then draw a conclusion.

One more clarification question:
With the nighttime setback, it refers to the time when the heating runs at the lower temperature, right? Basically also between 2 time windows during the day, correct?

That means if you read "we have no nighttime setback," then the heating basically runs continuously?

I think I'm confused right now.

Night setback refers to the time when the heating runs at a lower temperature, right? Basically also between two time windows during the day, correct?

So if you read "we don't have night setback," does that mean the heating basically runs continuously?

I think I'm a bit confused.

With setback, one has to differentiate. Normally, it is said that a temperature of, for example, only 18° should be maintained during the setback. However, in a well-insulated new building, this means that the heating is completely off during this time because the temperature doesn't drop that quickly at night. In an uninsulated old building, the heating would then run at "low flame" and only heat enough to maintain the setback temperature.

Ok, thanks, then I was right.
Of course, that would mean our Kfw70 would be off, because the temperature only drops by 1 degree when I have the heating running in night setback mode from 9 PM to 5 AM.

I'm curious about the new result.

Afterwards, we will simply let the heating run continuously, basically from 0 to 0, and then decide how to set it.

Because if the consumption is no higher, it can also run continuously, then it is ensured that it is comfortable when you come home earlier.