Abstract: A pressurized fluid cleaning system includes a fluid source, a discharge line leading to a spray discharge element, and a motor driven cleaner such as a cleaning brush to clean the spray discharge element. A sensor in the discharge line responds to fluid back pressure above a pre-established level (or to flow rate below a pre-established level) to actuate a cleaner "on" switch. Additionally or alternatively, a fluid sensor in an overflow line from the fluid source responds to fluid in the overflow line to actuate the cleaner "on" switch. The sensors are also connected to a warning device and to a delayed response system "off" switch to shut down the entire system for human intervention.