The solar assisted gas winter experiments were carried out in a typical winter day in Shanghai, two models of domestic hot water and hot water heating were adopted. The experiment platform applied S7-200 PLC as control system, used WinCC as the data acquisition software. The water temperature, flow rate and the radiation intensity of the solar radiation at different points of the system were collected. On the basis of the data, the influence of solar radiation intensity, outdoor temperature and system operation mode on the solar energy guarantee rate and gas consumption in Shanghai area were studied. The experimental results show that the meteorological parameters have a significant influence on the solar energy guarantee rate and the gas consumption. In fine weather (average radiation amount is more than 400 W/m²) under the heating mode of guaranteed solar rate reached 82%, overcast to cloudy (average radiation dose of less than 250 W/m²) was 54%. In fine weather in the heating mode of guaranteed solar rate could reach 10.3%, in overcast or cloudy conditions only 5.09%.