53 Pa. Stat. § 53318
Promotions shall be based on merits to be ascertained by examination to be prescribed by the commission. All questions relative to promotions shall be practical in character and such as will fairly test the merit and fitness of persons seeking promotion. The appointing officer or body shall notify the commission of a vacancy in the police force which is to be filled by promotion and shall request the certification of an eligibility list. The commission shall certify for each existing vacancy the names of the three persons on the eligibility list who have received the highest average score in the last preceding promotion examination held within a period of two years preceding the date of the request for the eligibility list. If three names are not available, the commission shall certify the names remaining on the eligibility list. The appointing officer or body shall make an appointment from the names certified based solely on the merits and fitness of the candidate unless the appointing officer or body makes objections to the commission regarding any of the persons on the eligibility list for any reason provided under section thirteen of this act.
The appointing body or officer shall have power to determine whether an increase in salary shall constitute a promotion.
53 P.S. § 53318