Combustion device and hot water device including same

A combustion device, comprising:

• a variable-speed fan;
• a premixing device having a gas flow path through which air flows internally by driving of the variable-speed fan, and a fuel gas outlet communicating with the gas flow path, in which fuel gas flows out from the fuel gas outlet into the gas flow path by negative pressure when the air flows through the gas flow path, and capable of generating an air-fuel mixture of the air and the fuel gas;
• a combustion chamber positioned on an exhaust side of the variable-speed fan so as to receive supply of the air-fuel mixture, and for combusting the air-fuel mixture;
• and
• an ignition device capable of ignition operation for the air-fuel mixture in the combustion chamber,
• wherein the premixing device includes a flapper capable of opening and closing a part of the gas flow path, and an opening degree of the flapper is larger in a case of a drive speed of the variable-speed fan being high speed than in a case of being low speed, and
• the ignition operation for the air-fuel mixture by the ignition device is configured as:
• a standard ignition operation in principle, which is executed in a first drive speed range of the variable-speed fan in which the flapper is in an open state, and exceptionally a non-standard ignition operation, which is executed in a second drive speed range of the variable-speed fan in which the flapper is in a closed state in a case where the air-fuel mixture is not ignited by the standard ignition operation.