Water heater status monitoring system

A method for determining a status of a water heater system, comprising:

• monitoring water temperature of a water heater that is heated by an appliance burner having an associated pilot device;
• monitoring a magnitude of a voltage output by a thermopile having a first end heated by the pilot device and a second end heated when the appliance burner is operating;
• and
• checking whether the water temperature exceeds a thermal cut out limit;
• and
• wherein:
• a fuel valve controls fuel to the appliance burner;
• the magnitude of the voltage output by the thermopile indicates a difference of temperatures at the first and second ends;
• if the water temperature exceeds the thermal cut out limit, then a monitoring is made for a change of the magnitude of the voltage output by the thermopile;
• if there is a decrease of the magnitude of the voltage output by the thermopile during an increase of the water temperature, then the appliance burner is operating and the fuel valve is closed to shut down the appliance burner;
• and
• if there is a decrease of the magnitude of the voltage output by the thermopile during an increase of the water temperature and the fuel valve is closed, then there is another source of heat affecting the water temperature and the second end of the pilot device.

A water heater system comprising:

• an appliance burner configured to heat water in a tank of a water heater;
• a water temperature sensor configured to detect a water temperature in the tank;
• a pilot device configured to ignite the appliance burner;
• a thermopile having a first end and a second end, and having an output voltage that represents a temperature difference between the first end and the second end;
• a control module connected to the appliance burner, the water temperature sensor, the pilot device, and the thermopile;
• and
• wherein:
• the first end of the thermopile is heated by the pilot device;
• the second end of the thermopile is heated by the appliance burner when the appliance burner is on;
• the voltage output of the thermopile is less, when the appliance burner is on, than the voltage output of the thermopile when the appliance burner is not on;
• the control module is configured to:
• monitor a water temperature indicated by the water temperature sensor and a voltage from the thermopile;
• monitor for a change of a magnitude of the voltage output by the thermopile when the monitored water temperature exceeds a thermal cut out limit;
• determine the appliance burner is operating and shut down the appliance burner when there is a decrease in the magnitude of the voltage output by the thermopile during an increase of the water temperature;
• and
• determine there is another source of heat affecting the water temperature and the second end of the thermopile when there is a decrease in the magnitude of the voltage output by the thermopile during an increase of the water temperature while fuel valve is closed.