A stacked proportioning valve having a body with at least two sets of ports disposed at different positions along a longitudinal length of the body, each set of ports including at least three ports at different angular positions to couple to fluid conduits, a rotor disposed in the valve body has at least two sections stacked along the longitudinal length, each section comprising three fluid channels in longitudinal alignment with one of the sets of ports, and a drive shaft affixed to the rotor, the drive shaft to rotate the rotor over angular positions to fluidly couple together pairs of ports in each of the sets of ports synchronously as a function of the rotor's angular position. In embodiments a component of a plasma processing chamber, such as a plasma etch chamber is fluidly coupled by the stack proportioning valve to reservoirs of both a hot and cold chiller.