Aquarium cold and hot water device

An aquarium cold and hot water device comprises a condenser, a compressor, an evaporator and a four-way valve, wherein a main valve pipe opening of the four-way valve is connected with a compressor high-pressure exhausting opening; a first secondary valve pipe opening of the four-way valve is connected with a condenser air inlet; a second secondary valve pipe opening of the four-way valve is connected with a compressor low-pressure air suction opening; a third secondary valve pipe opening of the four-way valve is connected with an evaporator air outlet; a drying filter is arranged between the condenser and the four-way valve; the condenser is connected with the evaporator by a capillary tube. The device can finish the conversion of cold water and hot water in one machine, and only a corresponding cold and hot switch needs to be changed, so that cold water and hot water can be obtained. The trouble of using a plurality of sets of devices is simplified.