A water heating apparatus includes: an exhaust gas passage through which an exhaust gas from a burner flows; a water flow passage through which water flows; a first heat exchanger configured to exchange heat between sensible heat contained in the exhaust gas and water flowing through a heat exchanger tube, and arranged at upstream side of the exhaust gas passage and downstream side of the water flow passage; a second heat exchanger configured to exchange heat between latent heat contained in the exhaust gas and water flowing through a heat exchanger tube, and arranged at downstream side of the exhaust gas passage and upstream side of the water flow passage; and a bypass pipe arranged in the water flow passage in such a position as to bypass the second heat exchanger and designed to allow a at least the predetermined minimum amount of water required for a burner combustion operation to flow therethrough into the first heat exchanger.