The invention relates to a self-control preheating central 
water supply system for gas water heaters. The 
system mainly comprises a 
water heater main body, hot / cold water inlet / outlet pipes connected with the main body, and 
control valves arranged on the pipes. Two or more 
water consumption branches are connected on the hot water outlet 
pipe. The central 
water supply system is characterized in that: the 
water heater main body is also connected with a circulating device via pipes, a 
master controller and a flow meter are arranged inside the main body; the 
master controller is also connected with a 
remote manipulator, the circulating device is provided inside with a controller, a temperature-sensitive probe electrically connected with the controller, a water 
circulating pump and a flow meter, a one-way valve is arranged on the loop of the circulating device, the remoter 
manipulator, the 
master controller and the controllers are connected with one another by means of two-way non-polar safety 
voltage carrier 
waves, the main controller receives information from the controller of the circulating device and the 
remote manipulator and collects temperature and 
water flow data of the main body for further analysis and treatment, thereby forming the 
automatic control system of central water preheating. The system has the advantages of multiple functions, full-automatic 
intelligent control and good application effect.