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 . <EOS>