Just one more thing to possibly add to your checklist.
Illinois Public Act 094-0741
Illinois residents and HVAC companies and service techs that perform work in Illinois be advised that House Bill 5284 requiring the installation of carbon monoxide alarms was signed by Governor Rod R. Blagojevich and goes into effect January 1, 2007.
Full text of the law is viewable at http://www.ilga.gov/legislation/publicacts/94/PDF/094-0741.pdf
Many will decry that the law does not go far enough and others will decry the intrusion of government into our lives. So be it.