Many Sellers, Real Estate Attorneys and Real Estate Sales Agents want a simple yes or no answer when a home inspector is asked the question: Is the air conditioning system functioning properly? However, a simple yes or no answer cannot address this question appropriately unless all of the following items are inspected during a home inspection.

  1. Is there evidence that the system was not professionally installed under the proper building permit and inspected by the local building department having jurisdiction?
  2. Is there evidence that the system has not been maintained properly?
  3. Is the system properly sized for the home?
  4. How old are the systems major components?
  5. Do the major components appear to be functioning properly?
  6. Are the evaporator and condensing coils clean and free of noticeable corrosion?
  7. Does the air filter element fit properly and is it keeping the evaporator coil clean?
  8. Is the condensate pan and air handler housing sufficiently water tight to prevent condensate leaks?
  9. Is there anything restricting air flow to the evaporator coil or condensing unit?
  10. Are there air leaks in the ductwork?
  11. Are there any signs of damage to the materials under the air handler due to condensate formation or leaks?
  12. Is condensate from the air handler managed properly and freely draining outside the home?
  13. Are there safety devices such as secondary pans and drains or leak detection shut off switches installed in or under the air handler?
  14. Are all cold surfaces properly insulated to prevent surface condensation from forming?
  15. Is the difference in the temperature of the supply air and return air between 15 and 20º F?
  16. Do the system controls function properly?
  17. Have there been condensate leaks that might have caused mold to grow in or around the air handler?
  18. If mold growth occurred was it properly cleaned and contaminated materials replaced?

A home inspector should be able to answer all of the above questions if these elements are reasonably accessible. Answering the above questions gives a good inspector enough information to assess the general condition of the system but it doesn’t mean that there aren’t any unseen problems. Should those above items cause concern for a home inspector, it is prudent to have an A/C service technician address them and perhaps perform some additional tests. There are additional checks that can be performed that take special equipment, some disassembly and considerably more time to complete.

These are:

  1. Testing the windings in the compressor for wear and potential shorts
  2. Checking for proper refrigerant charge and small leaks
  3. Checking the condition of the compressor lubricant
  4. Checking the condition of the contacts in the motor start circuits

Fully checking a single system usually takes a good A/C service technician about 1 hour. The cost is usually $80 – $150. These additional tests are usually not recommended unless the system is five years old or more. The older the system, the more inclined one should be to have the system professionally checked by a service technician.

For systems over 10 years it is recommended that they be thoroughly checked every year. Air conditioning systems have a life expectancy just like people do. The reliable service life expectancy of an air conditioning system is approximately 15 years. Factors like good care and maintenance and the quality of the original product will have effect on their longevity.

Systems over 15 years of age are not only unreliable but are likely no longer operating efficiently. The cost of operation can considerably affect one?s utility bills. Florida Power and Light has an incentive plan for people to get rid of older systems. Visit their website at for information on getting some financial help towards replacing an older inefficient system.

Carrier, Trane and Lennox all make good equipment however, these manufacturers have been known to make some mistakes in their designs over the years. Hiring a service technician that is familiar with a particular manufacturer and model is highly recommended. Ask a factory representative for recommended service contractors in your area. Most major manufacturers have websites with names and phone numbers that you can call.