Who should pay for the maintenance of water pipes when the rented house receives the property transfer?

According to the "Property Management Regulations", the maintenance of public facilities shall be undertaken by the owner of the related property (i.e. the owner). Therefore, you should contact the landlord in this case. If the landlord is the owner, the expenses shall be borne by the landlord. If the landlord is not the owner, you can let the landlord contact the ultimate owner or contact the property management company, where there is the contact information of the house owner, so that the property management company can contact the owner directly to solve the problem.