Abstract: A liquid heating device, comprising a pump for pumping a liquid, a convertor for converting of a flow of the liquid, heat exchange a unit, the convertor being formed as a cyclone connected with the pump and having a main spiral passage for a tangential supply of the liquid, passage a unit from withdrawal of the liquid, and an additional spiral passage which is directed toward a side which is opposite toward the main passage is directed, the spiral passages having outlets which are offset relative to one another along an axis of the cyclone.