The age of your air conditioner. The life of an air conditioner is somewhere between 10 and 20 years. So, if your air conditioner is more than 10 years old, it may be time for a replacement.

Rising energy bills. As air conditioners get older, they become less energy efficient. To see if your air conditioner is losing efficiency, compare your utility bills over the past few summers. If your costs are rising, it could be a sign that your air conditioner is wearing out.

Leaking refrigerant. Not only is refrigerant expensive, but refrigerant leaks will cause the compressor to eventually go out. The type of refrigerant that your air conditioner needs may also cause you problems down the road.

The cost of repair. Call your local HVAC company to get a free quote on repair costs. If it’s more than $3,000, it is probably cheaper to buy a new unit.