The McDonnell & Miller 144706 model FPC-1000-U (boilerwize) is a universal, field-configurable electronic low water cut-off with the extended barrel probe. It is field-configured for 24-volt, 120-volt, automatic, or manual operation for steam and hot water boilers. The boilerwize probe type low water cut-off uses patented technology to monitor changes in water conductivity. When it exceeds the defined parameters, the decision to turn off the burner is made based on the volatility/variability of the resistance readings. This patented technology provides the best protection without turning off the burner unless there is a low water condition. As an added safety measure, the control will turn off the burner if it recognizes an out-of-water condition when it exceeds the sensitivity threshold.