Abstract: An apparatus controls the treatment of water that flows through a cooling system. The electrical conductivity of the water is sensed. A valve control opens a system drain valve when the sensed conductivity is greater than a threshold, and closes the drain valve when the conductivity drops below the threshold by a given amount. The water drained form the system is replenished through an inlet and a mechanism measures the volume of water added to the cooling system. Chemicals to treat the water are fed into the system when specified volumes of water have been added. The sensing of conductivity can be inhibited for a certain period following the application of the chemicals. A possible system malfunction is indicated when the conductivity does not drop below the threshold after the drain valve is open for a given period of time.

Abstract: An apparatus controls treatment of water flowing through a boiler and includes a device that monitors the conductivity of the water. A controller opens a drain valve at periodic intervals, and closes the drain valve when the conductivity drops below a defined threshold. A mechanism measures the volume of water that flows into the boiler and a chemical is added to the water when a specified amount of water has flowed into the boiler. Alternatively the application of the chemical can occur at regular intervals of time. The chemical is applied for a user definable period of time. The application of the chemical is suspended when the cessation of water flow into the boiler is detected.