The purpose (obviously) of an air conditioner is to blow cool air, so if the air coming from the unit is warm, that should be the most obvious sign of trouble. Oftentimes, warmer air coming from your AC unit means there is a restriction in airflow. This could be caused by dirty coils (you have not had maintenance done recently) or the air filter has not been replaced in a while.

It is also possible that your outdoor unit is not getting electricity. There could be an issue with your circuit breaker or fuse panel that is causing your outdoor unit to not be supplied electricity. If it’s not an electrical issue, apart from on the machine may be malfunctioning or broken and requires a professional’s help to fix it. AC units can be tricky, and often times trying to fix it yourself can cause more harm than good.

Oftentimes, you can hear when something is not working correctly. If you are hearing your unit make sounds that you have not heard before, it is smart to have it checked out. Any kind of banging, buzzing, clanking, clicking, humming, squealing, screaming, or rattling could be an indicator that something isn’t right. Those sounds usually mean that parts inside the machine may be loose or going bad. Sometimes it ends up not being a big deal and the machine can still operate correctly, but typically those sounds are a sign of malfunctions to come down the road. Ignoring unusual sounds can create much bigger problems, so have a professional take a look and see if it’s no big deal or a problem that can be fixed before it becomes a much more expensive repair.

Did your monthly energy bill seem higher than usual? This could be an indicator that it’s time for maintenance to your AC unit. Air filter issues or duct leaks can cause your AC unit to have to run longer than usual to cool your home. The more your AC system runs, the more energy you use, and the more your bill increases.

Lack of maintenance on your unit can lead to failing parts or low refrigerant, which can both cause your energy bill to increase. If your AC unit is having to work harder to compensate for some kind of mechanical issue, it is going to use more energy than usual. So the next time you ask yourself “why is my energy bill so high?”, it may be time for AC service.

AC short-cycling is when your unit is continually turning on and off. AC unit short-cycling can cause damage to the system and require it to be replaced earlier than usual, which can be very expensive. Also, the power required by the machine to turn itself on and off repeatedly can cause a significant spike in your energy bill.

Short-cycling can be caused by a number of reasons, which is why it is important to have an HVAC professional investigate the problem. Refrigerant leaks, clogged air filters, and thermostat problems are common causes. It is also possible that your air conditioner is too large for the space that it is trying to cool. If your system is working hard to overcompensate for a malfunction or faulty parts, it can overheat. Overheating will cause the system to kick off before the cycle ends, which results in short cycling.

You know something is wrong if it is hot outside and you find frost build-up or a frozen ac unit. Refrigerant collects the heat in your home and moves it outside, making it a crucial part of your air conditioner. Refrigerant leaks usually happen due to natural wear and tear to your unit, and can cause your ac unit to be frozen. This can also be caused by improper airflow, where your unit is suffocating and not getting enough air.

Frozen indoor evaporator coils are another indicator that your unit is not working properly. If this happens, turn off your system and allow the coils to defrost completely. Similar to a frozen ac unit, frozen evaporator coils can be caused by airflow or refrigerant issues. It is also possible that the coils are frozen because they were dirty which can put an extra strain on the system. Another common cause can be having a drainage problem. If you have a clogged drainpipe, water can be backed up and freeze on your evaporator coils.