PURPOSE: To obtain excellent hot water supply characteristics and fuel characteristics by using a DC brushless motor having variable number of revolutions as a motor for driving a combustion fan of a hot water supplying apparatus.

CONSTITUTION: A combustion fan 1 is driven by a DC brushless motor 2 having a large starting torque. Thus, the fan 1 itself has high response to start and stop. A supplying time of the air to be supplied by the fan 1 to a burner 5 is shortened to follow up a responding time of a fuel supply side. Accordingly, a time of outputting hot water from a shower can be, for example, shortened, and excellent hot water supplying characteristics can be obtained for a change for switching a hot water cock on the way or an abrupt flow rate change, etc. Since it has speed control characteristics which can variably control number of revolutions in a wide range, optimum air ratio can be set to a burning range when a high load is applied to the burner 5. Accordingly, excellent combustion characteristics are obtained for a wide range.