The invention provides an automatic control energy-saving non-pressure water heater with domestic water. The water heater comprises a water heater liner, a shower water inlet pipe, a three-way joint, a water mixing valve, a heating pipe, a shower water outlet pipe, a water outlet normally open solenoid valve, a parallel flow connector, a shower nozzle, a domestic water inlet pipe, a water inlet normally closed solenoid valve, a domestic water outlet pipe, a water flow switch, a dry heating prevention water level de-energizing switch and a double-phase faucet. The water heater has the advantages that the plastic liner of the automatic control energy-saving non-pressure water heater is made of a PP-R pipe, thus the service life is prolonged; when the domestic water is used, the inlet water of the liner is controlled by the water flow switch, so that the liner reaches a non-pressure state, the defects that an open-type electric water heater cannot supply water for multiple places and is limited in function can be overcome, and the effect that cracking and water leakage caused by too large water pressure do not occur to a liner of a closed type electric water heater can also be ensured; and cold water pressure and hot water pressure are balanced through the parallel flow connector, the water temperature is controlled, and the defect of nonuniform outlet cold water and outlet hot water caused by different water pressures is avoided.