A rotary control valve (10) is provided for a liquid conditioning system. The rotary control valve includes a housing (12) having a chamber formed about a central axis. The housing includes a plurality of ports aligned with one another along an axis generally parallel to the central axis. A rotor (14) is located within the chamber and is selectively rotatable about the central axis. The rotor includes a central tubular wall extending along the central axis which includes a central fluid flow path. The rotor includes an inlet port adapted to provide fluid communication between the central fluid flow path and a source of untreated liquid. The rotor also includes a plurality of longitudinal sectors wherein each sector includes one or more radial chambers located in one or more tiers of the sector. One or more of the radial chambers in each sector includes an aperture to provide fluid communication between the central fluid flow path and the radial chamber. The radial chambers include respective peripheral apertures adapted to selectively place the radial chambers of a sector in fluid communication with one or more of the ports of the housing when the sector is rotated into alignment with the ports in the housing. Selective rotation of the rotor about the central axis to a selected rotational position opens and closes various fluid paths through the rotor and the housing.