No matter who the landlord complains about the leak in the rented house.

Legal analysis: the landlord can complain to the property if the rented house leaks. If the water leakage caused by house decoration affects the downstairs, the landlord shall be responsible for the losses caused. The landlord didn't change the fittings in time because of the aging water pipes, and the tenant just moved in and didn't know. The landlord is responsible for the loss caused by water leakage downstairs, and the tenant is not responsible. The tenant found that the water pipe was aging and the landlord did not replace it in time, causing losses downstairs. The landlord bears the primary responsibility and the tenant bears the secondary responsibility. If the tenant forgets to turn off the water pipe, the tenant shall bear all the responsibilities for the leakage loss downstairs.

Legal basis: Article 221st of the Civil Code of People's Republic of China (PRC). When the lease item needs maintenance, the lessee may require the lessor to maintain it within a reasonable period of time. If the lessor fails to perform the maintenance obligation, the lessee can carry out the maintenance by himself, and the maintenance expenses shall be borne by the lessor. If the maintenance of the leased property affects the lessee's use, the rent shall be reduced or the lease term shall be extended accordingly.