Control method and control system of gas water heater

The invention provides a control method and a control system of a gas water heater, and belongs to the technical field of constant temperature type gas water heater control. The control method of the gas water heater comprises the steps that the current load is determined according to the current water flow, the current water inlet temperature, the current water outlet temperature and a preset heating coefficient; according to the current load, and the minimum load, the maximum load, the wind pressure alarm value of the minimum load and the wind pressure alarm value of the maximum load corresponding to the number of the opened current fire rows, determining a current wind pressure alarm value; and when the current wind pressure value is larger than or equal to the current wind pressure alarm value, the fan is controlled to increase the rotating speed, and/or at least one fire grate in a closed state is started, so that the wind resistance is improved. According to the control method of the gas water heater, t