Furnace was operating when I arrived. The furnace is almost 20 years old. I found that the heat exchangers have failed. Screws are falling out that are responsible for holding the heat exchangers together. The furnace is leaking CO into the home. The furnace needs to be replaced asap and should not be ran. The furnace is very unreliable and is a fire hazard and a Carbon Monoxide hazard. The AC system is form 2008 and operates on obsolete refrigerant. The Azc system has inadequate flood protection. Both the AC and furnace are very old and may fail at anytime. The homeowner has been advised and assumes all risk and responsibility for operating an unsafe furnace.