PURPOSE: To prevent radiation of heat energy accumulated in a heat exchanger for heating during the OFF of heating combustion to improve heat efficiency.

CONSTITUTION: The title hot water supplying and heating device is formed of a heat exchanger 2 for heating in which hot water is circulated by a pump 1 and heated, a temperature detector 3 to detect the temperature of this heating hot water, a heating fan 5 to feed air for heating combustion, a hot water supply fan 8 to supply combustion air to a hot water supplying heat exchanger 7, and a control means 17 to stop combustion in response to an OFF signal of the temperature detector 3 during the heating combustion and to stop the heating fan 5, while keeping the hot water supply fan 8 rotating for a prescribed time. By the operation of the control means, heat radiation from the heat exchanger 2 is prevented during the OFF of the heating combustion by stopping the heating fan 5, whereby some conveniences such as an improvement of heat efficiency can be obtained.