A system prevents solenoids from overheating. The solenoid circuit has solenoids connected across a power supply. Control switches energize the solenoids by controllably connecting the solenoids to and from the power source. The protection system includes a master switch connected between the power source and the solenoids for simultaneously connecting and disconnecting all of the solenoids with the power source. A current sensor is positioned between the supply terminal of the power supply and the solenoids for detecting a current flowing between the supply and any of the solenoids and for producing a current-sensed signal. A controller detects abnormalities based on the current-sensed signal and responsively opens the master switch to disconnect all of the solenoids from the power source.