I also install fire detectors, flood sensors, and carbon monoxide sensors all linked to the alarm system to provide additional protection for my property, tenants, and myself. 

What special rules do I need to follow (e.g. proper number and placement of smoke detectors and carbon monoxide detectors) that might apply to a rental property that don't apply to a primary residence, or where can I find these rules?

Combustion reactions change lots of chemicals into lots of other chemicals, some of them being things like Carbon Monoxide, Tar, etc.Vaping is just basically a humidifier. 

I recently installed Carbonic Heat in one of my buildings. 

I currently have properties in Granite City, IL but am looking to buy in the Edwardsville/Glen Carbon area as well.

We don't really have a check list that we follow, however these are the things we look for when we do complete an inspection:- Smoke and Carbon detectors are operational- No apparent leaks when running faucets and toilets.

There is a somewhat substantiated theory that many haunted houses (when the folks are mentally stable) are related to carbon monoxide posioning.

And I'm opposed to the natural gas space heat that some suggest- it can cause long-term, low-level carbon monoxide exposure.

@McKinley Carbone Hey neighbor, do you work with Justin Silverio? 

And two of the units don't have carbon monoxide or smoke detectors.