Underfloor heating program too hot. Damage to screed - experts?

Hello,

21 days ago we had our cement screed installed and this morning the heating technician came and put the heating system into operation. In advance, he received a heating protocol from the screed installer with the required supply temperatures to be maintained (days 1-3 at 20 degrees, day 4 at 25, etc. up to a maximum of 45 degrees). This afternoon I came home from work and got a huge shock... It was very warm inside the house and the heating showed a supply temperature of 37 degrees. The screed also started to form bubbles in some places. I immediately turned off the heating and called the technician. Unfortunately, it was not the same one from this morning and he could not understand why it was set incorrectly; he only reset it and lowered the maximum value from 40 to 20.

I couldn’t see any major damage in the dark. The heating ran for about 6-7 hours with the wrong settings. Could there be further damage? What can I do to be protected in case of consequential damages? Thank you!

Nothing is missing at all! What is supposed to happen there?

Are you sure that comes from the heating and wasn't there before? I would have expected at most cracks by now.

With us, the screed was even continuously heated with 35 degrees flow temperature for 3 weeks, and it stayed as smooth as a baby's bottom ...

Where do you see a problem now? What should happen? Probably googled too much. You didn’t really expect the cement screed to be as smooth as a baby’s bottom before or after heating, did you?

I would have rather avoided installing the cement screed in the frosty temperatures of the last 3 weeks.

Cement or anhydrite?

Cement. But it was delivered 4 weeks early and not the usual 3 weeks before. We simply had no time pressure and therefore did not put too much pressure on the companies regarding the deadlines. Hence, almost 11 months of construction time

And yes, it was indeed smooth as a baby's bottom except for one spot.

No panic, everything is fine.