The 6 tons were the subject of discussion in one of your other threads. What would be an appropriate consumption in your view for a "new building Kfw 70" and what is this assumption based on? Apart from your horror, nothing gets through to the readers of the threads. I already asked above, and once again you did not answer, whether it was actually too warm in the apartments? Did you have 25 degrees in the place even though the thermostat was set to 20 degrees? If not, why then is the supply temperature too high? And why on earth don’t you finally call the professional craftsman?! The only thing that is not efficient is your approach (it is also not effective). Or are you just trolling – at this point that seems the most likely to me.