This is not an uncommon problem. In fact, we hear about it so much that we’ve compiled a list of the most frequent causes of, and solutions to the issue. Here are some steps you can start with:
Check Your Thermostat
It’s easy to overlook, but if your thermostat isn’t set right, it could explain why your vents are blowing warm air. Someone might have inadvertently bumped the thermostat to a higher setting. Also, is your system set to “auto”? If instead it’s set to “on”, your fans will continue to blow air even when the system isn’t running. We suggest setting your thermostat to “auto” to ensure that your AC always does what it’s supposed to: deliver cool air to your home.
Check Your Filter
If your thermostat isn’t the culprit, you might want to check your filter. If your filter is old, air will have a tough time passing through it. If you change your filter and cool air still isn’t blowing through your vents, then calling a professional to check it out would be a smart idea.
Check Your Condenser
Your outdoor unit—the condenser—could be covered in debris or surrounded by weeds and sticks. These elements will block air from passing into the condenser. Clear any blockage if air isn’t flowing properly into your unit. It might also be a good time to clean the entire unit, or hire an HVAC specialist to investigate and remediate the problem.
Check Your Circuit Breaker
If you find your condenser has lost power, your indoor unit could still be running, pushing warm air through your home. Check your circuit breaker first to make sure it hasn’t tripped. Next, find the breaker switch on your outside unit and flip the switch completely off and back on. If this doesn’t solve your issue, contact a professional to investigate whether your wiring is damaged.
When to Call a Professional…
If you’ve tried these steps and are still experiencing trouble with your AC, the problem might be more severe. In that case, don’t try to fix your system on your own (unless you happen to be an HVAC tech!)—you could make the problem worse.