If you've had the same AC unit for a while, you may be looking for signs that indicate it is time to replace your air conditioner. It's best to be proactive and stay ahead of AC troubles before they come knocking at your door. However, it isn't always easy to tell when you should replace your air conditioning unit.

Learn more about how long air conditioning units last, signs that they need to be replaced, when you can repair and how to purchase an energy-efficient unit.

How long do central air conditioning units last? 

Air conditioning units can last a long time. This is especially true if they’re well maintained, and any repairs that may need to be done are done quickly. However, the average lifespan of your air conditioning unit depends on several factors including:

  • The type of air conditioning unit 
  • The size of the unit
  • The quality of the system
  • How well you've maintained the unit

How long an AC unit lasts can also depend heavily on the type of system you have. With this information in hand, you can make a more informed decision whether it is time to replace the unit in your home or if you can wait. 

Here are the average life spans of several types of air conditioning units:

If your air conditioning unit is past this threshold, you may want to start looking for signs to repair or replace it.


Replacing your air conditioning unit is no small feat, and it can often cost thousands of dollars. However, if your air conditioning system isn't working correctly or efficiently it may be time to replace it. Here are some ways you can tell that it needs to be replaced.

  • It isn't cooling efficiently after routine cleaning and maintenance. Cleaning or replacing your air conditioning unit's filter is one of the first steps to keeping it in excellent shape. If you regularly replace the filter (every three months) and the unit still uses an excessive amount of energy compared to its initial intake, you may need to replace it.
  • There is excessive condensation, or it doesn't drain properly. When condensation doesn't drain due to a clogged drain, it can affect your home's indoor humidity levels and cause water damage.
  • Strange smells or odors are coming from the unit. While heating/cooling systems produce a slight smell when you turn the heater mode on for the first time, they shouldn't create any other odors during use
  • Your air conditioner is making unusual sounds. Modern air conditioners usually operate silently or near-silently. If there are any loud banging or rattling sounds, this could be a sign of broken or damaged components.

If your central air conditioning unit is experiencing any of the issues we just discussed, it might be time to start shopping for a new one. That being said, purchasing a new AC unit might not be in the cards for everyone. 


If you aren't able to completely replace your air conditioning unit at this time or your unit is within its lifespan, here are a few ways to maintain or repair your system for less.

  • Ductwork issues: Part of your AC unit's inefficiency may be hampered by leaks in your ducts. When ducts are damaged and leaky, they force your system to work harder to make up for the lost air. A certified contractor can look at your ducts to make sure they are sealed and insulated correctly.
  • Your AC unit needs to be cleaned: If your home has an air-source heat pump, the air pump may need to be cleaned if it has debris, grass clippings or foliage blocking the heat pump condenser fan.
  • Replacing the filter on your air conditioning unit: One of the most common ways air conditioners lose performance is by blocking airflow and causing the unit to work harder to bring air into the home. Lack of airflow raises the amount of energy needed to power the unit.
  • Insulation and sealing around window units: If you are using a window unit to cool part of your home, make sure that the insulation around the unit has sealed it completely. 
  • Adding or replacing insulation in your home: Poor insulation and air leaks can lead to a loss of conditioned air. Adding or replacing insulation in your attic or basement can help you to reduce the amount of energy your AC unit has to expend to keep your home comfortable.

For those who might not want to replace their AC unit just yet, the above tips might help return your old unit to its former glory. At the very least, these improvements might improve the efficiency of your AC unit, which could save you money on your electric bill. 


If your air conditioning unit is showing signs of age and inefficiency, make sure to choose an ENERGY STAR system to replace it. The type of system you should purchase is entirely up to your situation. You need to factor in your budget, your home's current layout and long-term energy savings. 

For more information on how to take control and save energy in your home, check out our top tips page and blog. To learn more about rebates on energy-efficient air conditioning units, visit your local electric cooperative's website for more information.