When temperatures rise in the greater Greenville, SC area, your air conditioner should be keeping your home cool and comfortable, not making things worse. If your AC blowing hot air, it’s a clear sign something isn’t working properly. An air conditioner blowing warm air can quickly turn from a minor inconvenience into a major comfort issue, especially during peak summer heat. In some cases, the fix is simple. In others, it may require professional repair. Below are three common reasons your AC blowing hot air, and what you should do next.
Incorrect Thermostat Settings
- The thermostat is set to “Cool”
- The temperature is set lower than your current indoor temperature
- The fan is set to “Auto” rather than “On”
If the fan is set to “On,” it runs continuously, even when the system isn’t actively cooling. This can cause warm air to circulate between cooling cycles, making it feel like your AC blowing hot air when it’s actually just moving unconditioned air. If everything looks correct and the problem continues, it’s time to look deeper.
Low Refrigerant or a Refrigerant Leak
One of the most common and serious reasons for an AC blowing hot air is low refrigerant. Refrigerant is the substance your system uses to absorb heat from inside your home and release it outdoors. Without enough refrigerant, your AC can’t properly cool the air.
Signs of a refrigerant issue include:
-
Warm air coming from vents
-
Ice forming on refrigerant lines or the indoor coil
-
Hissing or bubbling noises
-
Longer cooling cycles
-
Higher-than-normal energy bills
Refrigerant does not get “used up.” If levels are low, it typically means there’s a leak. This is not a DIY fix — handling refrigerant requires a licensed HVAC professional. Ignoring the issue can lead to compressor damage, which is one of the most expensive AC repairs. If your AC is blowing hot air and you suspect refrigerant problems, it’s best to call for service as soon as possible.
Restricted Airflow
Airflow restrictions are another frequent cause of an AC blowing hot air. When your air filter becomes clogged with dust and debris, it reduces airflow throughout the system. This forces your air conditioner to work harder than necessary and can cause internal components to overheat or freeze up.
Over time, restricted airflow reduces cooling efficiency and may cause warm air to circulate through your home. Checking and replacing your air filter every one to three months during the cooling season helps maintain steady airflow and supports proper system performance. In Greenville’s long, humid summers, clean airflow is especially important for maintaining comfort.
Outdoor Unit Issues
Your air conditioning system depends on both the indoor air handler and the outdoor condenser unit working together. If the indoor system is running but the outdoor unit is not functioning properly, your AC may circulate uncooled air throughout your home.
Electrical issues, tripped breakers, failing capacitors, or debris buildup around the condenser can interfere with the system’s ability to release heat. If you notice that the outdoor unit is not running while your indoor unit is on, or if it seems unusually quiet, it may be contributing to your AC blowing hot air. Outdoor unit problems should be inspected and repaired by a licensed HVAC professional to ensure safe and proper operation.
AC Repair in Greenville, SC
If your AC blowing hot air and basic troubleshooting doesn’t solve the issue, the team at Eastergard HVAC is here to help. We provide professional air conditioning repair services throughout the greater Greenville, SC area and can quickly diagnose the root cause of your cooling problem. Whether it’s a refrigerant leak, airflow restriction, electrical failure, or duct issue, our experienced technicians will restore your comfort fast — so you can get back to enjoying a cool, comfortable home.
Don’t let the South Carolina heat take over your home. If your AC is blowing hot air, contact Eastergard HVAC today and get your cooling system back on track before a small issue becomes a major repair.