Household coffee machine with calcification indicator

摘要

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.