Finally, a simple and nice question again ;-)
Is there a heat load calculation or what kind of radiator was installed? Then you have two options.
1. Exchange 1:1
2. Exchange for a heat pump-compatible radiator
Heat pump-compatible radiators that work well with a heat pump even with rather poor energy efficiency are type 33 radiators. Radiators from the hardware store or "brand goods" are almost irrelevant. Maybe brand goods have slightly better values. Recently, I simply ordered (but for a whole apartment) online. Buderus (that's Bosch) radiators, which you can often find in hardware stores as well.
You can also decide based on appearance. Smooth or ribbed. Depending on the connection situation (where the pipes are located) there are different models. With appropriate adapters/S-connection fittings, for example, pipes placed "at the wrong height" can also be connected. Mounting material is usually included.
If you ever want to go towards a heat pump or reduce the flow temperature in the whole house, then take type 33 radiators directly. You can also check out or compare at heizungsdiscount24 (or other large shops).
Sorry for replying so late! I would simply like to replace somewhat good but inexpensive 22 series radiators. The plan is to additionally heat with an air conditioner.
The heating installer who explained our gas system to me said that you cannot simply read or set the flow temperature?!? It’s a Junkers ZSB condensing boiler (about 14 years old).
So if that’s the case, how am I supposed to try out how low I can go with the flow temperature?
I’m a bit clueless.
I do not want to replace the heating system.