Heat source machine formed by connecting gas water heaters in parallel and control method

The invention discloses a heat source machine formed by connecting gas water heaters in parallel and a control method. The heat source machine comprises a main water inlet pipe, a hot water convergence pipe, a main gas inlet pipe, gas water heaters and a system controller. The gas water heaters are connected in parallel through the main water inlet pipe, the hot water convergence pipe and the main gas inlet pipe. Each gas water heater is internally provided with a water flow collecting sensor, a water inlet temperature detector and a water outlet temperature detector and is connected with the system controller through a communication bus and a signal converter arranged on the communication bus. A water inlet electromagnetic valve is arranged on a cold water pipe of each gas water heater and connected with the system controller through a water inlet switch control line. During working, data of each gas water heater are transmitted to the system controller, the number of the gas water heaters needing to work is