A modular vacuum toilet, and a method of servicing such a toilet, are disclosed. The toilet is used with a vacuum toilet system having a sewer line placeable under partial vacuum pressure and a source of rinse fluid. The modular vacuum toilet comprises a frame and a removable bowl engaging and supported be the frame, the bowl defining an outlet and having a rinse fluid dispenser associated therewith. The modular vacuum toilet also has a valve set module. The valve set module includes a discharge valve having an inlet in fluid communication with the bowl outlet, an outlet in fluid communication with the sewer line, and a movable discharge valve member disposed between the discharge valve inlet and outlet. A rinse fluid valve is also incorporated into the valve set module and has an inlet in fluid communication with the source of rinse fluid, an outlet in fluid communication with the rinse fluid dispenser, and a movable rinse fluid valve member disposed between the rinse fluid valve inlet and outlet. The valve set module further includes a flush control unit having a circuit board operably connected to the discharge valve and rinse fluid valve for controlling actuation of the discharge valve member and rinse fluid valve member.