ANTI-FREEZING OPERATION FOR ADDITIONAL FIRING AUTOMATIC BATH DEVICE

PURPOSE:To reduce a noise during an anti-freezing operation by a method wherein a temperature of hot water flowing in an additional firing circulation pipe passage is detected, the operation is carried out with a low capability in case of a high detected temperature of hot water and the operation is carried out with a high capability only when the detected hot water temperature is low. CONSTITUTION:When a detecting sensor 11 detects XON deg.C, a pump 6 is driven at its capability being high and as a remaining hot water in a bath tub 5 flows into a circulating pipe passage 4, a switch 7 is turned on and a temperature of hot water in the pipe passage 4 at that time is detected. When a detecting sensor 8 detects that the temperature is more than a hot water temperature XOFF deg.C where an anti-freezing operation is not required and detects that it is more than a hot water temperature X deg.C where a subsequent operation can be changed over to a low capability of the pump, the pump 6 is stopped and at the same time this signal is inputted to a micro-computer control part. In case that the sensor 11 may detect again XON deg.C, the pump 6 is operated while the capability is being kept of its low value. At this time, it is detected by the sensor 8 whether temperature is increased up to a certain predetermined temperature (t deg.C) within a certain time (t) and it is further detected that the increased temperature is attained, resulting in that it is discriminated that the detected temperature is more than the hot water temperature XOFF deg.C or not and if it is less than XOFF deg.C, an operation of the pump is continued and in turn if the temperature is more than XOFF deg.C, the operation is stopped.