Common HVAC systems in the Cary and Raleigh, NC, area, the packaged unit, also known as a “gas pack” is an efficient piece of equipment that contains both the AC unit and the gas furnace.
These units have a limited lifespan. If the home or the heating equipment is more than 8 to 10 years old, I strongly urge my real estate Buyer clients to have a licensed HVAC contractor check them, inside and out during their home inspection. In that 8 to 10 year period of time it is not uncommon for the heat exchanger to corrode and perforate. The heat exchanger contains the combustion flue gases from the furnace burner. When the wall of the exchanger perforates, the furnace may possibly allow poisonous carbon monoxide gas to enter the home. “That can’t be a good thing” comes to mind.
Here is a photo of a corroded heat exchanger that has experienced dramatic failure:
That unit is a hazard to occupants. Much less importantly, it also no doubt ran the heating and cooling bills sky high due to leaking conditioned air out of the home.
This heat exchanger is in a 16 year old furnace and has probably been replaced, as it appears to be brand new:
For a $100-$150 inspection fee, why risk it? Why accept the possibility of an unsafe, worn out heat exchanger to save the inspection fee?
That $100-$150 is money well spent for peace of mind.