Your son signed a one year lease, which is a fixed term lease, not a periodic lease, so that legally the landlord can request payment in full up front. The monthly payment most people are paying is only a convenience, not a legal requirement.
Under certain circumstances you can withhold rent or reduce rent if the landlord fails to repair, but only when the failure to repair constitutes a breach of warranty of inhabitability, or his conduct constitutes partial or total physical eviction. Under such circumstances you should always consult a lawyer before taking any action.
