What does dry rotation mean in a mini hot water pump? The "dry rotation" in micro diaphragm hot water pumps refers to the phenomenon where the inlet of the pump fails to provide sufficient liquid during pump operation, resulting in the impeller of the pump being unable to receive water support and rotating at high speed. This situation may be caused by water source interruption, pipeline blockage, damage to the inlet pipeline, unreasonable water pump inlet position, no liquid filled before the pump, presence of gas or other foreign objects at the inlet, or damage to the pump rotor. Why does a dc hot water pump need to run dry? The main reason why a hot water pump needs to run dry is to prevent the water inside the pump from freezing or crystallizing, which may cause damage to the pump. In a frozen environment, if the water inside the pump freezes or crystallizes, it can cause pressure and compression on the internal components of the pump, thereby damaging the se…