A heat supply apparatus, comprising: an outdoor unit including a heat exchanger configured to exchange heat between refrigerant and water; a load unit using heat of heat-exchanged water as a load; and an indoor unit configured to supply water discharged from the outdoor unit to the load unit, and configured to supply water discharged from the load unit to the outdoor unit, wherein the indoor unit comprises: a case defining an outer shape; a first connection pipe disposed in the case and configured to transfer water introduced from the outdoor unit to the load unit; a second connection pipe disposed in the case and configured to transfer water introduced from the load unit to the outdoor unit; and a pump disposed at the second connection pipe and configured to pump water of the load unit to the outdoor unit; and wherein the second connection pipe comprises: a pump inlet pipe disposed at an upstream side of the pump, and a pump outlet pipe disposed at a downstream side of the pump, and wherein the pump inlet pipe is provided with a strainer configured to filter foreign substances contained in water introduced from the load unit; and wherein the pump inlet pipe comprises: a first pump inlet pipe extending upward from a lower plate of the case and including a bending portion that changes a flow direction; and a second pump inlet pipe connecting one side of the first pump inlet pipe and the pump, and wherein the strainer is disposed at an end portion of the first pump inlet pipe. an outdoor unit including a heat exchanger configured to exchange heat between refrigerant and water; a load unit using heat of heat-exchanged water as a load; and an indoor unit configured to supply water discharged from the outdoor unit to the load unit, and configured to supply water discharged from the load unit to the outdoor unit, wherein the indoor unit comprises: a case defining an outer shape; a first connection pipe disposed in the case and configured to transfer water introduced from the outdoor unit to the load unit; a second connection pipe disposed in the case and configured to transfer water introduced from the load unit to the outdoor unit; and a pump disposed at the second connection pipe and configured to pump water of the load unit to the outdoor unit; and a case defining an outer shape; a first connection pipe disposed in the case and configured to transfer water introduced from the outdoor unit to the load unit; a second connection pipe disposed in the case and configured to transfer water introduced from the load unit to the outdoor unit; and a pump disposed at the second connection pipe and configured to pump water of the load unit to the outdoor unit; and wherein the second connection pipe comprises: a pump inlet pipe disposed at an upstream side of the pump, and a pump outlet pipe disposed at a downstream side of the pump, and wherein the pump inlet pipe is provided with a strainer configured to filter foreign substances contained in water introduced from the load unit; and a pump inlet pipe disposed at an upstream side of the pump, and a pump outlet pipe disposed at a downstream side of the pump, and wherein the pump inlet pipe is provided with a strainer configured to filter foreign substances contained in water introduced from the load unit; and wherein the pump inlet pipe comprises: a first pump inlet pipe extending upward from a lower plate of the case and including a bending portion that changes a flow direction; and a second pump inlet pipe connecting one side of the first pump inlet pipe and the pump, and wherein the strainer is disposed at an end portion of the first pump inlet pipe. a first pump inlet pipe extending upward from a lower plate of the case and including a bending portion that changes a flow direction; and a second pump inlet pipe connecting one side of the first pump inlet pipe and the pump, and wherein the strainer is disposed at an end portion of the first pump inlet pipe.