Air heating apparatus

An air heating apparatus comprising:

• an expansion tank configured to store water;
• a water heating device configured to receive heat from combustion gas generated by a combustion reaction and heat the water;
• a heating heat exchanger configured to receive the water heated by the water heating device and conduct heat exchange between air to be released for heating and the water;
• a fan configured to supply the air to the heating heat exchanger;
• and
• a case in which the water heating device, the expansion tank, the heating heat exchanger, and the fan are disposed,
• wherein the case includes:
• an outer box;
• a first partition wall coupled to the outer box and configured to extend in a reference direction to divide the inside of the outer box into a first partition space and a second partition space;
• a second partition wall disposed in the first partition space so as to be perpendicular to the first partition wall;
• and
• a third partition wall disposed in the second partition space so as to be perpendicular to the first partition wall, and
• wherein the expansion tank and the fan are coupled to the third partition wall.