(A) If, upon completion of an evidentiary hearing, the commission finds that the order appealed from was lawful and reasonable, it shall make a written decision affirming the order appealed from. If the commission finds that the order appealed from was unreasonable or unlawful, it shall make a written decision vacating the order appealed from, and making the order that it finds the chief should have made or remanding the matter to the chief for further proceedings.
(B) All decisions of the commission shall incorporate:
(1) Findings of fact;
(2) Conclusions of law; and
(3) An order granting or denying relief.
(C) When a final order is issued, the commission shall give notice thereof by certified mail to all parties to the proceeding.
(D) The decision of the commission is final unless vacated by the courts in an appeal as provided for in section 1509.37 of the Revised Code.