A fabric treatment appliance comprises a steam generator having a chamber configured to hold water; a supply conduit configured to transport water to the steam generator chamber; a temperature sensor configured to sense a temperature representative of the steam generator chamber at a predetermined water level in the steam generator chamber; and a controller coupled to the temperature sensor and configured to control flow of water through the supply conduit based on the sensed temperature to control the level of water in the steam generator chamber. The disclosure provides methods of water supply control that can employ the temperature sensor.