Equipment inspectors commonly find
- Forced-air gas furnaces in attics, closets or garages.
- Wall and floor furnaces in older homes and many apartments.
- Central air conditioners with an outdoor condenser and an indoor coil.
- Heat pumps, which provide both heating and cooling, and ductless mini-splits.
- Evaporative coolers in some inland areas.
What gets evaluated
- Operation: does the system start, run and stop with the thermostat?
- Temperatures: supply and return temperatures, to see whether the system is heating or cooling as expected.
- Venting: the flue for gas appliances, its slope, connections and clearance to combustibles.
- Combustion area: flame appearance, rust, scorching and signs of rollout.
- Condensate: drain lines and secondary pans for units in attics.
- Filters and ducts: filter condition and visible ductwork for damage or disconnection.
- Disconnects and clearances: electrical disconnect near the condenser, clearance around the outdoor unit.
Age and refrigerant
Most furnaces last 15 to 25 years and most air conditioners 12 to 20 years, depending on climate and maintenance. The manufacture date is usually printed on the data plate.
Air conditioners installed before 2010 often use R-22 refrigerant. Its production was phased out in the United States in 2020, so recharging an older system can be expensive. Newer equipment uses R-410A or newer lower-impact refrigerants such as R-454B.
Older heating systems
Wall and floor furnaces are often found in mid-century homes and apartments. Issues include missing or damaged vent connectors, combustibles stored too close, and no shutoff valve in the room. Some older floor furnaces can’t be serviced because parts are no longer made.
Indoor air and safety
Any gas-burning appliance is a potential source of carbon monoxide. California requires CO alarms in homes with fuel-burning appliances, a fireplace or an attached garage. If the heater is old or shows signs of poor combustion, have it serviced before move-in and confirm CO alarms are present and working.
Getting the most from the findings
Ask the seller for service records. A 17-year-old unit with annual service is a different risk from one that has never been opened. If replacement is likely, get a quote that includes any duct work, electrical upgrades and permits.
Common questions
Can the inspector test the air conditioner in winter?
Most inspectors won't run an air conditioner when the outdoor temperature is below about 60°F because it can damage the compressor. The report will note that the unit wasn't tested.
Should I have the ducts tested?
If the ducts are old, crushed or poorly sealed, a duct leakage test by an HVAC contractor can be worthwhile. Some older ductwork contains asbestos wrap, which should be identified before any work.
What does a cracked heat exchanger mean?
The heat exchanger separates combustion gases from the air you breathe. A crack can let carbon monoxide into the house. Inspectors can only see part of it, so a suspected crack should be confirmed by an HVAC contractor, and the furnace usually needs replacement.