US Patent 11172801 Full recovery tank shutoff

A cleaning system comprising a vacuum source, a current sensor, a recovery tank having a shutoff float configured to float on a surface of fluid within the recovery tank, and a controller. The vacuum source is in fluid communication with a suction inlet via first and second air paths within the recovery tank. The shutoff float is further configured to block the first air path upon the fluid within the recovery tank reaching a desired level. The controller is configured to receive, from the current sensor, a signal indicative of the current drawn by the vacuum source. The controller is further configured to determine, based on the current drawn by the vacuum source crossing a threshold, the fluid within the recovery tank has reached the desired level and control an operating element of the cleaning system upon determining the fluid within the recovery tank has reached the desired level.