The invention relates to a novel water heater, which comprises a shell. The shell internally comprises a control cavity and a heating cavity; a water inlet pipe and a water outlet pipe are respectively arranged on two ends of the heating cavity; adapters are respectively arranged on outer ends of the water inlet pipe and the water outlet pipe; a water guiding cover is connected to the inner end of the water inlet pipe, and comprises an annular side wall; one end of the side wall is correspondingly connected onto an inner end pipe wall of the water inlet pipe; the other end of the side wall is sealed by a baffle plate; a water outlet is formed on the side wall and is located in the heating cavity. The side wall of the water guiding cover and the baffle plate stops the movement of water, so that the water can only be discharged from the water outlet of the side wall, helicoidally flows in the heating cavity under the action of water pressure, and can be heat more uniformly, the heat transfer efficiency is improved, and the heating effect is better; meanwhile, the novel water heater provided by the invention is simple in structure, small in size, and convenient to install; and people can get hot water anytime anywhere when going out with the device.