Warranty on heating

Good evening,
our house was handed over about 1 year ago. So we are still within the 5-year warranty period. Our house has a "normal" radiator heating system. Subsequently, we had an underfloor heating system installed by a heating company different from the one used by the developer. Now the heating company that installed the original heating system on behalf of the developer claims that we have lost all warranty claims on the heating system due to the installation of an underfloor heating system (only on the ground floor).
Can you tell us if this is the case? I would be very happy to receive your answers. Thank you

How does the heating company justify that?

Was the already installed heating system somehow altered during the installation of the underfloor heating (even small details can be relevant)?

No, as far as I understood, only 2 "switches" or something like that were installed. The actual heating remained untouched

Good evening,

Can you tell us if that is the case?

Short & sweet: yes

Best regards from the Rhineland