Defective lifting system, who pays?

You can believe me, it is like that, at least with engines. With windows, you are comparing apples and oranges, or are the hinges motorized?

With the heating, even if it is, for example, the pump, and ventilation also 100%.

What about electric roller shutters? Also no warranty from day 1?

Yep, if it’s the motor. However, the likelihood is higher that there will be a goodwill replacement where the window installer can possibly make use of their warranty with the manufacturer. This usually happens initially with reservation because the manufacturer checks why the motor is broken. Short circuits, for example on the connection side, are clearly visible. You’re welcome to keep searching, just because you’ve never heard or experienced it doesn’t mean it can’t be the case.

"Interesting" claim, but I wouldn't know how that fits into the current legal situation/jurisprudence. According to the Building Code, you have a 5-year warranty. This applies primarily to everything connected with the house. I find no restrictions for "pumps". if you have something concrete, please specify (belief is not enough for me).

Yep, if it's the motor.

Sorry, but you are talking complete nonsense.

According to the Building Code (Baugesetzbuch) 634a paragraph 1 number 2, the installation of roller shutters (motors) is considered work on a building. Therefore, defect warranty claims last 5 years.

According to VOB - if agreed upon - it is two years. For maintenance, also longer.

Warranty and guarantee are two totally different things after all. Unfortunately, most people do not know the difference. However, I deal with it regularly, and yes, with the statutory guarantee on "things," the burden of proof shifts after 6 months. But only in B2C transactions. Warranty applies as stated in the warranty conditions, which the warrantor can design quite freely. However, they must then adhere to them. And legally stipulated matters like the building code are something completely different.