Can you tell me whether you can lay tiles on the screed, under which is already included a warm floor? The glue, of course, is special, for warm floors, but I am confused by the accelerated evaporation of moisture from the solution.
Tile installation only when the heating field is off, turn on the underfloor heating 3-4 weeks after tile installation.
If there is an opportunity to turn off the floor heating when installing tiles, then any sensible person will turn it off, if there is no such an opportunity, then turn off the floor at least in those rooms where the tile is laid
In general, it seems to me, you can not turn it off, if the surface temperature of the floor heating corresponds to the temperature of the adhesive. It seems to be most often from +5 to +25, it is necessary to look at the data of the specific manufacturer. I now maintain a comfortable 15-16 degrees in the house, the temperature on the floor surface is not above 18.5 degrees. And what happens to the adhesive at this t °? I strongly suspect that nothing. I do not plan to turn it off during installation. If your floor is "warm" – above 25-27 degrees Celsius, it makes sense to reduce the supply temperature a day or two before installation, wait until it cools down to 20 degrees and then start.