Patent ID: 8162232
Filing Date: 2012-04-24
Classification: C23F,F24H

Abstract:
1. A method of controlling the operation of a water heater, the water heater comprising a tank, a heating element, an electrode, and a sensor configured to detect an electrical characteristic of a circuit formed by the tank, the electrode, and water in the tank, the method comprising: applying a voltage to the electrode; acquiring a signal from the sensor, the signal having a relation to the applied voltage; determining whether the water heater is in a dry-fire state based on the acquired signal; limiting activation of the heating element when the water heater is in a dry-fire state; determining a conductivity of a fluid in the tank based on the signal when the water heater is not in a dry-fire state; wherein the sensor includes a voltage sensor; wherein the acquiring a signal from the sensor comprises sensing a potential of the electrode relative to the tank; wherein the method further comprises ceasing application of the applied voltage; wherein the sensing a potential occurs after the ceasing application of the applied voltage; and wherein the determining whether the water heater is in a dry-fire state includes determining whether the sensed potential is less than a threshold, the threshold indicating a dry-fire state.