Experiences with gas boilers, which brand etc.

Without being able to recommend anything to you directly, Brötje is also over a hundred years old and in my opinion also one of the well-known established brands.
What is important when choosing is also what your plumber installs on a daily basis, because normally he is only familiar with that and can help you directly, otherwise you always need the factory service.

It is my wife's house, which she has just bought.
Therefore, we do not have fixed heating companies there. When I search for local partners on the Brötje website, you find almost as many in the same area as with Viessmann. Just Hannover city... there is more selection than in the countryside where we live.

I think we will first see how big the price difference actually is. I have by now a better feeling about Brötje.
You don't read much more bad about it than about other brands.

Last year we replaced our boiler and obtained three quotes. It happened to be three different manufacturers. The unit from Brötje was the most expensive, followed by Viessmann and then Vaillant. The difference between Viessmann and Vaillant was small; in the end, we decided on the boiler from Vaillant.

Ours is a Junkers, it has been running trouble-free since 2017. It is easy to use.

Attached is the offer we received from our desired manufacturer. What do the experts say about it? :)

You don't have storage? Why not? If not, OK, then you need the power. If you do have storage, the boiler is extremely oversized.

Is the old heating system still running? If yes, please stay calm and switch to the heat pump slowly but surely. The gas price increase from the creation of the thread until today should actually be a clear enough hint.