The commission shall act only by motion on all matters considered by it for determination, but procedural and evidentiary rulings may be made by the chairperson or presiding member subject to reversal upon an appeal of the ruling of the chair. A majority of the members of the commission shall constitute a quorum for the transaction of business. Action by the commission shall require the affirmative vote of three members, except that a lesser number may adjourn from time to time. (Prior code § 34.14.1414)