A steam generator and a method for generating steam, the generator comprising a steam chamber fed with water from a water from a water reservoir for heating by a heating source to generate steam, steam being delivered out through a steam outlet, and waste water being evacuated through a drain, the steam generator comprising a control chamber, in fluid communication with the steam chamber so as that a water level in the control chamber is indicative of a water level in said steam chamber; at least one water level-sensor configured for detecting the water level in the control chamber; and a control unit receiving a signal from the water level-sensor. There is further provided a method of generating steam in a steam chamber receiving Water is fed from the water reservoir simultaneously to the steam chamber and to the control chamber, through a single feeding valve, the feed water being mixed with hot waste water drained from the steam chamber, upstream of a drain pump.