Probably another wave of outrage is about to start and I'll be accused of bringing about the end of the world. But here, half-truths are always being spread from time to time.
My personal experience says the following.
The restrictions from 2024 refer to the installation of a new heating system. What counts as a heating system?
The gas boiler, the chimney or flue, the radiators, the valves and safety groups, the hot water boiler or instantaneous water heater.
As long as you don’t replace everything, it’s not a new heating system, but merely the repair or replacement of individual components. If the gas boiler breaks down in 5 years, you simply have a new one installed. If necessary, a used or demonstration unit.
Of course, you can clarify all this with someone who knows about it beforehand. This is usually the responsible district chimney sweep master.
This also applies to oil boilers, oil burners, or both. However, here you have to note that you can only buy condensing boilers now. The chimney must then also be renovated, from unbreakable stainless steel pipe to ceramic pipe. You can avoid this nonsense by stocking a well-used oil boiler including burner. They are currently available cheaply.
My old oil boiler was just measured by the chimney sweep. Best values. Built in 1992. I once bought the entire heating system on Ebay for 15 euros. With everything included. It has been running without problems for 15 years now with me.
My chimney sweep and energy consultant said about heat pumps that they usually only last 15 years. Then they are broken.