It’s 90 degrees outside, and your AC is blowing warm air — again. If your home feels more like a sauna than a sanctuary, you’re not alone. Many Durham homeowners run into this frustrating issue during the hottest months.
Sometimes, it’s a simple fix. Other times, it signals a deeper issue that needs professional attention. In this post, we’ll cover the most common reasons your AC might be blowing warm air — and what you can do next.
Need help now? Call Hays HVAC or book online for same-day AC service in Durham, NC.
9 Reasons Your AC Is Blowing Warm Air
1. Thermostat Settings Are Incorrect
Start with the basics — is your thermostat actually set to “cool”? Sometimes, it may have accidentally been switched to “heat” or “fan only.” Make sure the temperature is set lower than the current room temp and that “auto” is selected.
2. A Tripped Circuit Breaker or Power Issue
If the indoor unit is working but the outdoor condenser is not, a tripped breaker could be the culprit. Reset it once — but if it trips again, call a professional. Electrical issues can pose serious risks.
3. Dirty Air Filters
A clogged air filter restricts airflow and can cause your system to overheat or shut down the cooling process. Check and change filters monthly during peak summer usage.
4. Frozen Evaporator Coils
If you see ice buildup or reduced airflow, your coils may be frozen. Causes include low refrigerant, dirty filters, or blocked return air vents. Turn off your system and call a technician.
5. Low Refrigerant or a Leak
Low refrigerant usually means a leak — and without enough refrigerant, your AC can’t cool properly. This is not a DIY fix. We’ll find the leak, seal it, and recharge the system.
6. A Dirty or Blocked Outdoor Unit
Leaves, dirt, or debris can clog the outdoor condenser and prevent heat release. Use a garden hose to gently rinse off dirt, but avoid bending the fins. Annual professional cleaning is ideal.
7. Ductwork Problems
Leaky or disconnected ducts can send your cool air into attics or crawlspaces. You might notice weak airflow or hot and cold spots around your home.
8. Compressor or Electrical Failure
The compressor is your AC’s engine. If it fails, your system can’t cool. Electrical issues like bad capacitors can cause similar problems. Both require professional repair or replacement.
9. Your AC Is Just Too Old
If your unit is over 10–15 years old, declining performance is inevitable. Even if repairs help temporarily, it may be more cost-effective to upgrade.
Related: When Should You Replace Your Air Conditioner?
DIY Fixes vs. When to Call a Professional
| Issue | Can You Fix It? | Call a Pro? |
|---|---|---|
| Thermostat Settings | ✅ Yes | ❌ No |
| Dirty Filters | ✅ Yes | ❌ No |
| Tripped Breaker | ❗ With caution | ✅ Yes |
| Frozen Coils | ❌ No | ✅ Yes |
| Low Refrigerant | ❌ No | ✅ Yes |
| Compressor Failure | ❌ No | ✅ Yes |
If you’re unsure or uncomfortable performing any checks, don’t risk it — contact our AC experts for a fast, affordable fix.
Prevent AC Problems with Regular Maintenance
- Change your air filter every 1–2 months during the cooling season
- Keep the area around your outdoor unit clear of debris
- Schedule an annual AC tune-up each spring
Related: Seasonal HVAC Maintenance Checklist
AC Blowing Warm Air? Hays HVAC Has You Covered.
Whether it’s a quick filter change or a full system issue, we’re here to help. At Hays Heating and Air Conditioning, we provide fast, expert AC repairs across Durham and surrounding areas.
???? Call us now at (919) 471-8020 or schedule service online for fast, friendly help.
