Why Your AC Isn’t Cooling Properly

There’s nothing worse than walking into your home on a scorching summer day… only to find your air conditioner blowing warm air. If you’ve been frantically Googling “why is my AC not blowing cold air”—you’re not alone.

At Sermon Service & Electric, we get this call all the time during peak summer. Let’s break down the most common reasons your AC might be underperforming—and what you can do to stay cool.

1. Your Thermostat Settings Need a Double Check

We know—it sounds too simple. But you’d be surprised how often a thermostat is set to “ON” instead of “AUTO.” When it’s set to “ON,” your AC fan keeps running even when it’s not actively cooling, which can feel like it’s blowing warm air.

What to do:
Make sure your thermostat is set to “AUTO” and COOL, and check that the temperature is set lower than your room’s current temp.

2. Dirty Air Filters Are Blocking Airflow

Clogged filters are one of the most common culprits behind AC issues. When filters are dirty, airflow gets restricted—meaning cool air can’t properly circulate throughout your home.

What to do:
Replace your air filter (ideally every 1–3 months in summer). It’s a quick fix that can make a huge difference.

3. The Outside Unit Is Dirty or Blocked

If your outdoor AC unit (called a condenser) is covered in dirt, leaves, or debris, it can’t release heat efficiently. That means your system will struggle to cool your home properly.

What to do:
Turn off the power and gently rinse the unit with a hose. Keep at least two feet of clear space around it for proper airflow.

4. Low Refrigerant Levels

Refrigerant is what actually cools the air in your system. If your AC is low on refrigerant—usually due to a leak—you’ll notice reduced cooling and sometimes even ice on the unit.

What to do:
This one’s a job for the pros. Call an HVAC technician to check levels, find leaks, and recharge the refrigerant if needed.

5. Frozen Evaporator Coils

Frozen coils can block airflow and stop your AC from cooling. They’re often caused by dirty filters, low refrigerant, or poor airflow.

What to do:
Turn off the AC to let it thaw, change your filter, and call us if it happens again—it may point to a deeper issue.

6. Electrical Issues or Faulty Components

Sometimes the problem is a worn-out capacitor, a faulty motor, or a tripped breaker. Electrical parts wear out over time, especially if your system hasn’t been maintained regularly.

What to do:
Don’t mess with electrical components unless you’re trained. We can quickly diagnose and safely repair any system issues.

7. Your System Is Just Too Old

If your AC is over 10–15 years old, it may not be cooling like it used to. Older systems lose efficiency and have a harder time keeping up with rising temps—especially during East Idaho’s hottest months.

What to do:
It might be time to consider an upgrade. We’ll help you find a new, energy-efficient system that’s the right fit for your home and budget.

Still Wondering Why Your AC Isn’t Blowing Cold Air? We Can Help.

Your comfort matters—especially when temperatures are soaring. If your AC isn’t keeping up, don’t sweat it. At Sermon Service & Electric, we specialize in fast, friendly diagnostics and repairs that get your system back on track quickly.

Whether it’s a quick filter change or a full system tune-up, we’re here to make sure your home stays cool when it matters most.