Combustion heat source device

A combustion heat source device comprising:

• a housing;
• a burner housed within the housing;
• a combustion fan configured to supply air for combustion to the burner;
• a heat exchanger configured to be heated by combustion of the burner;
• a temperature sensor configured to detect a temperature of fluid flowing into or out of the heat exchanger;
• and
• a controller,
• wherein the controller is configured to operate the combustion fan when the burner is operating,
• a rotation speed of the combustion fan when the burner is operating corresponds to a heating amount by the burner, and
• the controller is configured to increase the heating amount by the burner when the heating amount by the burner is within a first heating amount range and the temperature detected by the temperature sensor exceeds a first reference temperature corresponding to the first heating amount range, so that the heating amount by the burner enters a second heating amount range that is higher than the first heating amount range.