Abstract: A household coffee machine of the type including a thermostatically controlled electric flow heater coupled to cold water supply and having a hot water outflow is provided with a calcification indicator connected electrically in parallel with the heater thermostat. The calcification indicator includes an indicator, such as a buzzer or glow lamp, in series with a thermal cut-out switch which is disposed in thermally responsive association with the line coupling the cold water supply to the flow heater. The series connected thermal cut-out switch and indicator have a high impedance in order to insure that the calcification indicator does not respond when the heater thermostat is closed.

Abstract: A coffee making machine having a calcification indicator system which turns an indicator device on and off to warn of the presence of calcine deposits in the water flow path of a flow heater is disclosed. The coffee machine calcification indicator system includes a glow lamp in a circuit arrangement with a signal flasher circuit. At least a portion of the calcification indicator system is connected in a parallel circuit arrangement with a heater thermostat switch. A calcification indicator switch is actuated at a time dependent upon the conclusion of the coffee making process to disable the operation of the calcification indicator device.