Abstract: An automatic livestock waterer has a water trough, a float valve assembly, a water pump, and a heating system. The float valve assembly is positioned in the water trough to maintain a desired water level. The water pump has an inlet connected to a suction line for drawing water from a water source, such as a pond or stream, and an outlet for delivering water to the water trough via the float valve assembly. The heating system includes a gas burner located under the water trough for preventing water in the water trough from freezing during cold weather conditions. A rechargeable battery is connected to the water pump and the heating system for supplying power for pumping water and for electronic ignition of the gas burner. A housing supports the water trough in an elevated position above the ground and contains the heating system and water pump below the trough.