765 ILCS 735/1
Whenever, pursuant to any agreement, either written or verbal, a landlord or his or her agent is required to pay for any water, gas or electrical service, the landlord shall pay for the services to ensure that the services are available to the tenant throughout the term of the lease and shall pay for the services in a timely manner so as not to cause an interruption of the services. If the landlord or his or her agent does not pay for such service, the tenant, or tenants in the event more than one tenant is served by a common system of water, gas or electrical service, including electrical service to common areas, which goes through a common meter in a single building, may either (i) terminate the lease; however, the termination of the lease under this Section does not absolve the landlord or tenant from any obligations that have arisen under the lease prior to its termination under this Section; or (ii) pay for such service if the nonpayment jeopardizes the continuation of the service to the tenant or tenants, as the case may be. The utility company shall not terminate service for such nonpayment until the utility company mails, delivers or posts a notice as specified in Section 3 to all tenants of buildings with 3 or more residential apartments. Upon receipt of such payment of the past due cost of such water, gas or electrical service owed by the landlord, the provider of such service shall immediately restore service to such tenant or tenants. In the alternative, the provider of such service shall immediately restore and continue such service to any tenant who (a) requests that the utility put the bill in his or her name; (b) establishes satisfactory credit references or provides for and pays a security deposit pursuant to the rules and regulations of the Illinois Commerce Commission applicable to applicants for new utility service; and (c) agrees to pay future bills. Any sums the tenant or tenants, as the case may be, pay for water, gas or electrical service that the landlord or his or her agent was required to pay may be deducted from the rent due by the tenant or tenants, and the total rent is diminished by the amount the tenant or tenants, as the case may be, have paid for the continuation of the water, gas or electrical service.
765 ILCS 735/1