Air heating apparatus

An air heating apparatus comprising:

• an expansion tank configured to store water;
• a water heater configured to receive heat from a combustion gas generated by a combustion reaction and heat the water;
• a heating heat exchanger configured to receive the water heated by the water heater and exchange heat with air to be discharged for heating;
• a fan configured to blow the air to the heating heat exchanger;
• a case in which the expansion tank, the water heater, the heating heat exchanger, and the fan are arranged;
• and
• a switch part electrically connected to an electric circuit for operating at least one of the expansion tank, the water heater, the heating heat exchanger, and the fan and configured to selectively open or close the electric circuit,
• wherein the case includes:
• an outer case having a first opening in a reference direction that is one direction perpendicular to a vertical direction;
• and
• a first opening cover coupled to the outer case and configured to cover the first opening when coupled to the outer case,
• wherein the first opening cover includes:
• a communication part passing in the reference direction and configured to expose a water inlet for replenishing the water in the expansion tank in the reference direction;
• and
• a water replenishment cover configured to cover the communication part, and
• wherein at least a portion of the switch part is in contact with the water replenishment cover.