An electric flow-through liquid dispenser including means for avoiding retaining liquid between the dispensing outlet (9) and a heater (4) or cooler. Instead, the liquid may be recirculated through the heater or cooler in the next dispensing operation. Alternatively, the liquid may be evacuated before the next dispensing operation. Alternatively, the heater or cooler may be disposed immediately behind the outlet, so that the retained volume of liquid is minimized. A flow- through heating apparatus comprising a heated flow path and a downstream depressurising means is also disclosed. Also disclosed is a superheated steam generator using a flow- through heater.