Abstract: A mobile unit for cleaning warewashers at a facility includes a base structure with wheels to facilitate movement. A cleaning system is mounted on the base structure and includes a tank, an external recirculation delivery line running from the tank and including a pump therealong and an external recirculation return line running back to the tank. The delivery line and the return line are connectable to a warewash machine for recirculating liquid from the tank through the warewash machine and back to the tank for cleaning of the warewash machine. The machine of the previous aspect may include an on-board controller that automatically carries out cleaning operations, or the machine may be a manual machine that is operator controlled.