It’s a humid July afternoon in the Philadelphia suburbs, and your air conditioner is running—but your home still feels like a sauna. You check the vents and feel only warm air drifting out. What gives?
In Bucks County, where summers are known for their sweltering humidity and climbing temperatures, a non-cooling AC isn’t just uncomfortable—it’s a real problem. Before you assume the worst, there are several common culprits that could be behind your system’s performance issues. Below are eight of the most frequent reasons an AC might stop cooling—and what you can do about it.
1. Clogged or Dirty Air Filter
Your air filter is your system’s first line of defense. When it gets clogged with dust, pollen, or pet hair, airflow becomes restricted. That means your system has to work harder to push out cool air, often with underwhelming results.
Local Tip: Bucks County’s spring and summer pollen counts can be brutal, especially in wooded areas like Newtown and Yardley. Replace your filters every 1 to 3 months, especially if you have pets or allergies.
2. Thermostat Settings Are Off
It might sound simple, but incorrect thermostat settings are a common reason for cooling issues. If your system is set to “fan only” instead of “cool,” it will circulate air without lowering the temperature.
Check that your thermostat is on the correct setting and that the batteries are working. If you’re still experiencing problems, it may be time to upgrade to a smart thermostat for better control and efficiency.
3. Low Refrigerant Levels
Refrigerant is essential to cooling your home. If your AC is low on refrigerant due to a leak or improper installation, it won’t be able to remove heat from the air effectively.
This isn’t something you can fix yourself—handling refrigerant requires a licensed technician. If your system is blowing warm air or hissing, or you notice ice on the refrigerant lines, call The Coop for a professional inspection.
4. Frozen Evaporator Coils
Evaporator coils absorb heat from your home’s air, but if they get too cold, they can freeze over—especially when airflow is blocked or refrigerant is low. The result: warm air from your vents.
Turn off your system to let it thaw, and avoid running it until it’s checked. Persistent freezing indicates a deeper issue that needs attention.
5. Dirty Condenser Coils
Your AC’s outdoor unit expels heat from your home. But when the condenser coils are covered in dirt, leaves, or grass clippings—especially common in yard-heavy areas like Chalfont or Perkasie—they can’t release that heat efficiently.
Cleaning the condenser coils carefully can improve performance. Just be sure to turn off the power before doing any outdoor maintenance. When in doubt, have a professional give your system a deep clean.
6. Leaky or Blocked Ductwork
Your duct system is how cool air travels throughout your home. If there are leaks, blockages, or poorly insulated areas, you could be losing precious cold air into the attic or crawlspaces instead of your living room.
Older homes in Quakertown and surrounding areas often have aging ductwork that could use resealing or repair. A thorough duct inspection can restore comfort and reduce energy waste.
7. Electrical Issues or Failing Capacitors
If your outdoor unit isn’t running, the issue may lie in the electrical components—often a bad capacitor or tripped breaker. These parts help your system start and stay running, and when they fail, your AC can’t function properly.
Electrical issues aren’t DIY territory. If you suspect an electrical failure, it’s best to call a licensed professional for a safe fix.
8. Your System Is Too Old or Improperly Sized
Age matters. If your air conditioner is more than 12 to 15 years old, it may be nearing the end of its lifespan. Likewise, a system that’s too small or large for your home won’t cool effectively and could cycle improperly.
In Bucks County, many older homes—especially in historic areas like Warminster—have outdated or poorly sized HVAC systems. If you’re dealing with ongoing issues, it may be time to consider an energy-efficient AC replacement. The Coop can help you evaluate your current setup and find the right fit for your home.
Don’t Sweat It! The Coop Has You Covered
Your AC works hard during a Bucks County summer. If yours isn’t keeping up, these eight problems could be the reason. Some fixes are quick and simple. Others need professional attention.
Whether you need a quick repair or a full system assessment, The Coop is here to help. Our licensed technicians provide reliable, transparent service to keep your home comfortable—no matter how hot it gets outside.
Still feeling the heat? Schedule your AC service with Cooper Mechanical today.
AC Repair FAQs
Why is my AC running but not cooling the house?
If your AC is running but blowing warm air, it could be due to a clogged air filter, frozen evaporator coils, low refrigerant, or incorrect thermostat settings. A professional HVAC inspection can pinpoint the issue.
How do I know if my AC needs more refrigerant?
Signs of low refrigerant include reduced cooling performance, hissing sounds, ice on the refrigerant lines, or longer-than-normal cooling cycles. Only licensed HVAC technicians can safely recharge your system.
Can a dirty air filter cause AC not to cool properly?
Yes, a dirty air filter restricts airflow, making your system less effective. In high-pollen areas like Bucks County, filters should be replaced every 1–3 months to maintain cooling efficiency.
How long should an AC unit last in Bucks County, PA?
Most central AC systems last 12 to 15 years with regular maintenance. Older systems, especially in historic Bucks County homes, may need replacement sooner due to efficiency loss or outdated components.
Should I repair or replace my AC if it’s not cooling?
If your AC is under 10 years old and the issue is minor, repair is usually the best option. However, frequent repairs, rising energy bills, or poor cooling may indicate it’s time to upgrade to a more efficient system.
What’s the best thermostat setting during summer in PA?
To balance comfort and energy savings, set your thermostat to 76–78°F when you’re home and raise it slightly when you’re away. Smart thermostats can automate these settings for Bucks County’s summer heat.
Why does my AC freeze up in hot weather?
Frozen coils in summer are often caused by restricted airflow or low refrigerant. Turning the system off to thaw and calling an HVAC technician is the safest course of action.
Can duct issues cause poor AC cooling in older homes?
Absolutely. Leaky, blocked, or uninsulated ducts—especially common in older Bucks County homes—can waste cool air and cause uneven temperatures throughout the house.
