James Reeder-Smith
This will depend if the bathroom radiator is set up as the heat sink/link radiator in the system - there must always be one radiator that is permanently on and links the flow and return of the system to protect the whole system in case all other rads are turned off and the heating tries to run. If this radiator is that one then no it should not be removed and capped, you will need to make another radiator the heat sink and ensure it never gets turned off (removed TRVs etc) to protect the system. once this is done yes you can cap the pipes and remove it (although you will end up with a colder bathroom).
