The invention provides an instant
refrigerant water heater, which comprises a compressor, a water
heat exchanger, an air-cooled evaporimeter and a
throttle that are connected in series. The invention is characterized in that, the water
heat exchanger comprises at least one
refrigerant pipeline, which is in form of coiled
pipe; on the
refrigerant pipeline, a
water pipe is looped for carrying out water heat exchange; the
water pipe has a water inlet and a water outlet, which form the heating channel of the water; the refrigerant pipeline and the
pipe are connected to form a refrigerant circulation
system. The advantages with the invention are that the refrigerant pipeline of the water
heat exchanger is located in the
water pipe for exchanging heat with the water, the heat-exchanging area is big, the
heat transmission rate is high, and the efficiency is high; the invention can be used once the heater is on, is very easy to use. In the water heat exchanger, the refrigerant pipeline is arranged in the water
pipe, and a refrigerant leaking arrangement is provided, which can prevent the water from being contaminated. The invention saves 75% energy than an electric
water heater, and is free from any accident such as personal damage due to current leakage or any
gas poisoning, is energy-saving, environmental friendly and safe to use.