RIGL 23-27.3 & RIGL 45-24.3 are what you're looking for for building code and occupancy code respectively.

>It is also the landlord's responsibility to make sure all electrical, plumbing, sanitary, heating, and other facilities (and appliances provided as part of the rental agreement) are kept in operable condition and meet housing code standards.

and

>He or she is also obligated to provide hot and cold running water at all times and must provide heat (68 degrees minimum but it may be higher under some local ordinances) between October 1st and May 1st, except when heat or hot water are generated by an installation controlled solely by the tenant and supplied directly by a public utility connection.

RI Landlord-Tenant Handbook(PDF) is your friend, and should be your LL's too. Seems like they're one of the ones that give the rest of us a bad name.