How much should a new gas boiler cost?

Actually, the neighbors mostly shop with us because the nuclear power plants are shutting down one after another... Check the current situation in FR.

And the conditions under which nuclear and gas are supposed to become "green," you obviously haven't read either.

What does "is coming to an end" mean? Is it more of a feeling, or is there really something wrong?

A new boiler would probably be condensing, which might require a new flue system (this was the case with our very old chimney; I am not familiar with systems that are 20 years old). If that is the case, there would be a heat pump as an alternative. Especially since there are subsidies for that and there will be more in the future.

I would look at this without ideology once the subsidy uncertainty has cleared up.

If it is urgent, better talk to the local craftsman – he (and not the internet) has to carry out the work anyway.

Your effort to save the world is honorable, but hijacking almost every thread here to flood it with your heat pump nonsense is sometimes annoying. Here, someone is asking about a gas boiler, not, as you think, how to save the world.

And “we have to” absolutely nothing.

Heat pumps are all well and good, but what does your overall ecological footprint look like? Do you forgo vacation trips (plane? car? or local area?)? I hope you don’t have a car (whether electric or diesel doesn’t matter, bike or train) available? No cellphone? Or all that other tech junk from China (PlayStation for the kids, for example)? Hopefully not? In your house, is there only one heated room (the cozy living room)? In your big house, do at least 20 people live (high sqm per person isn’t very eco-friendly either, right)?

I’m really interested. I also know someone like that (who, by the way, doesn’t have a heat pump, heats his 1920s house with gas, apparently the economist in him shows), who wants to tell me (or the whole world) what to do (ecologically), but already owns his fifth car in a few years, has a hybrid company car parked in front despite home office, goes to Portugal with the camper, e-bike, e-scooter because he’s supposedly eco… Daughter zips around Europe with interrail, pursues horse riding as a hobby (yes, horses also have a poor footprint), always has the latest iPhone but nicely goes to Fridays for Future demos with dad and tells me “no, I don’t drink beer from a can… out of conviction” when he once stopped by for a beer… or all that stuff about how everything should be done.

I’ll bet my ecological footprint is better, despite a diesel parked in front, a powerful fun car in the garage, and an oil heating system in the basement, than that of some environmental terrorists… ;)

Did you see the smiley? I also didn’t say that we are currently shopping. Just wait until electricity demand rises further and energy from abroad is cheaper. If you really want to be green, you shouldn’t build a single-family house, have an air conditioner, travel, or even have children. The heat pumps in Germany do not save the global climate. But everyone is welcome to make a small contribution. Only the missionary approach should be avoided. Purely monetarily, in this case, a new gas boiler is better.

A new boiler would probably be condensing, which may require a new exhaust system (that was the case with our very old chimney; I am not familiar with systems that are 20 years old).

20 years old = is already condensing technology. So take out the old boiler, screw in the new one, and that's it. Initial cost probably around €2,500 all in for a basic unit. Sensibly, I would calculate around €4,000 all in.

No, the Sieger HG11 is still a heating value device without condensing technology. The LAS will also still be missing. I think 4T all inclusive in today's times is rather unrealistic.