Gas heating water heater

The utility model discloses a gas heating water heater which comprises a water heater body, a main heat exchanger arranged on the water heater body, a combustor used for heating the main heat exchanger, a plate heat exchanger, a double-channel condensation heat exchanger, a heating pipeline and a bathroom pipeline. A first channel and a second channel which are not communicated with each other are arranged in the double-channel condensation heat exchanger; the heating water return end of the heating pipeline sequentially communicates with the first channel, the main heat exchanger and a first port of the three-way valve, a second port of the three-way valve is connected with the heating water outlet end of the heating pipeline, and a third port of the three-way valve sequentially communicates with the plate heat exchanger and the heating water return end of the heating pipeline. The bathroom water inlet end of the bathroom pipeline is connected with the bathroom water outlet end of the bathroom pipeline throu