The invention relates to a mixed non-static pressure water heater, with long service life and central water supply function. It comprises a water bank, a heating system, a cold water tube, a hot water tube, while the cold water tube and the hot water tube are connected to the water bank. It is characterized in that: the inlet tube and the cold water tube have a closed electric control inlet valve between them; the water bank and the overflow tube have a open electric control overflow valve between them; the highest overflow point of overflow channel formed by the electric control overflow valve and the overflow tube is near or higher than the highest point of water bank; the power source of electric control inlet valve and electric control overflow valve are controlled by the water flow sensor; the outlet valve is a mixed water valve whose hot water inlet is connected to the hot water tube and cold water inlet is connected to the inlet tube; said water flow sensor is at the cold water channel formed by tap water tube, inlet tube, mixed valve and the outlet of mixed valve. |