Open-loop control system of coffeemaker waterway

The utility model discloses an open-loop control system of a coffeemaker waterway. The open-loop control system comprises a water pump, a boiler and a brewing machine. The water outlet end of the water pump is connected with the water inlet end of the boiler, the water outlet end of the boiler is connected with the water inlet end of the brewing machine through the first water outlet end of a two-position three-way valve, the control system further comprises a potentiometer and a heater, the potentiometer is serially connected in a drive circuit of the water pump, and the heater is arranged on the two-position three-way valve. Voltage at two end of the water pump is regulated through the resistance of the potentiometer so as to regulate pumping pressure of the water pump, stability in different output water pressures of the water pump is guaranteed, and measurement is more accurate; by the heater arranged at the two-position three-way valve, heat loss of hot water can be reduced effectively.