New construction with freshwater station: scalding/freezing = 1 shower

Dear forum members,

We had a fresh water station "sold to us" in our new building. So my question goes in the same direction as my predecessor's...

In short: I scald and freeze almost simultaneously during just one shower! That is quite an achievement! Unfortunately, it is usually too cold... by the way, of course also when no water is being drawn otherwise...

Is it possible that our plumbing expert set something incorrectly? Do you have any tips for a solution?

I am very grateful!

Best regards
Tita

Pretty sure yes. Freshwater has nothing to do with incorrect temperature control. Does this happen with all fittings? Perhaps a mixer is also defective. Or is everything modern and very small in size and someone else is pressing the flush....

Thank you for your response! Yes, it also happens with other faucets, but it feels less intense in the kitchen than when showering or in the bathtub. But of course, you notice it more there... As I said, it is independent of whether someone else in the house is drawing water elsewhere or not. I will probably contact our builder again. I hope I will be successful. First of all, thank you very much! Best regards, Tita