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 perpendicular to an up-down direction to divide the inside of the outer box into a first partition space and a second partition space;
• and
• an air guide seated on an upper side of the first partition wall and fluidically connected with a communicating hole formed in the first partition wall, the air guide being configured to extend upward,
• wherein the first partition space is located above the second partition space,
• wherein the heating heat exchanger is disposed above the air guide in the first partition space,
• wherein the fan is disposed in the second partition space below the air guide, and
• wherein a guide member is coupled to the outside of an upper end of the air guide to guide sliding of the heating heat exchanger in the reference direction.