The problem is that the boiler cannot have "multiple recipes". It has the input filter, that can be deleted and output filter, that makes defined production. If the input filter will be nil, then any input fluid gives steam by the output.
I see the right solution as new entity, that has filters "steam" by input and output, as burner boiler, as electric boiler, as heat pipe boiler. Maybe uranium-heated boiler for extra big factories.