Whenever necessary for the purpose of enforcing the provisions of this Plumbing Code, or whenever the Plumbing Inspector has reasonable cause to believe that there exists in any building or structure or upon any premises, any condition which makes such building, structure or premises unsafe, the Plumbing Inspector may enter such building, structure or premises at all reasonable times to inspect the same or to perform any duty imposed upon the Plumbing Inspector by this Plumbing Code; provided that if such building, structure or premises is occupied, he shall first present proper credentials and request entry. If such entry is refused, the Plumbing Inspector shall have recourse to every remedy provided by law to secure entry.