A water spray system applied directly to cooking units in a kitchen rather than to the ventilating duct for the cooking units. The system may be a wet system with water pressure maintained at spray nozzles which open in case of fire, or an open head, or dry, system controlled by thermostats and a solenoid water valve. Safeguards are provided against loss of water pressure, surges in the water supply line, flare ups after partial cooling of the thermostats, closing of a solenoid gas valve supplying gas burners in the cooking units as a result of momentary outages in the electric service supplying the control circuits, and other contingencies.