When an air conditioner starts blowing warm or room-temperature air, this is a sign that one of its components needs repair. These problems are typically related to your home's air filter or some electrical component that controls how and when the air conditioner turns on. Here are three possible causes and how you can get them fixed.
Dirty Air Filter
Typically, your home's air filter should be replaced every two to three months, assuming you use your air conditioner for at least a few hours every day. If a filter gets too dirty, it can severely restrict the flow of air through your system, which can, in turn, cause your air conditioner to either shut down or malfunction.
When airflow is restricted, your air conditioner needs to work harder to pull in enough air to cool, which puts a strain on your system. If there is too much strain, your air conditioner may shut itself down to avoid damaging vital components.
This can also cause your compressor to freeze, which will prevent your air conditioner from running properly. Check your outdoor unit and look for any signs of ice on the evaporator coils. If they're frozen, a dirty air filter may be the culprit, though this can also happen if your coils haven't been cleaned as a part of regular maintenance. Try changing your air filter, and if that doesn't work, contact a technician to help fix the problem.
Blown or Failed Fuse
Your air conditioner's fuses are designed to take the brunt of any electrical problem, saving your much more expensive parts from damage. If your fuses have blown, you may hear a humming sound from your outdoor unit, but the fan inside won't be turning. This is because your motor isn't getting the power it needs to run properly.
Check your fuse box and check for any signs of wear or damage. Fuses can last for years, so if they're very old, it could be that there are no electrical issues and that they could simply no longer work correctly.
A technician can help you replace your fuses and troubleshoot the problem to make sure any electrical problems are isolated to just your fuses.
Capacitor or Circuit Issue
One of the most important parts of your air conditioner is your capacitor. The capacitor is what gives enough power to your motor to get the fan moving and then keep it running. If your capacitor has failed, your motor won't have the power to run properly or at all. Capacitors cost a little more to replace than fuses, but the good news is this often means the problem isn't with the motor itself, which can be more serious.
Another possibility is a problem with the circuit your air conditioner runs on. Air conditioners usually operate on dedicated circuits, which means that electrical problems are isolated and not noticeable until you try using your air conditioner. One such problem you might experience is a circuit breaker that keeps tripping. If the breaker trips repeatedly, this could indicate a more serious electrical problem that needs immediate attention. Call a technician to inspect your circuit, and avoid using your air conditioner in the meantime if at all possible.
Reach out to an AC repair professional if your AC is having troubles.