A greywater recovery and reuse system is shown, including a body for collecting, reconditioning and discharging greywater. The body has an inlet connection to a source of greywater; a filter for filtering the greywater; a tank for receiving the filtered greywater; a disinfector for disinfecting the filtered greywater; a pump for discharging the reconditioned greywater from said tank to a toilet that needs flushing water; a discharge connection to a sanitary sewer system; a fresh water connection and a control system for controlling the operation of the greywater recovery and reuse system. The system includes a controller for operating the system and dealing with certain alarm and status conditions. Methods of operating the system are also comprehended.