It’s a hot summer day in Palatine, IL, and your air conditioner is running, but the house still feels like a sauna. If your AC isn’t cooling, you’re not alone. This is one of the most common problems homeowners face during peak heat, and it can be frustrating.
Luckily, many AC issues have simple explanations, and sometimes even simple solutions.
Let’s go over the top reasons your AC might not be cooling properly and what you can do before calling in the pros. And if you do need expert help, On The Mark Heating and Air is the #1 choice for AC maintenance and repair in Palatine, IL, and the surrounding areas.
This is the most overlooked AC problem, and one of the easiest to fix.
What happens:
When your air filter is clogged with dust and debris, it blocks airflow. That means your system can’t move enough air through the house to cool it properly.
What you can do:
Check your filter. If it looks dusty or gray, replace it. Filters should typically be changed every 1 to 3 months, depending on how much you use your system and whether you have pets or allergies.
Before assuming the worst, make sure your thermostat is working the way it should.
What happens:
It might be set to “fan” instead of “cool,” or the temperature could be set higher than you thought. Dead batteries or faulty sensors can also cause problems.
What you can do:
Double-check the settings. Make sure the mode is set to “cool,” not “fan,” and that the temperature is set below the current room temperature. If your thermostat uses batteries, try replacing them. If it still isn’t working right, it might be time for a new one, possibly even a smart thermostat.
Yes, ice can be a problem—even in the summer.
What happens:
If your evaporator coils freeze, your system can’t pull heat from your home properly. This is often caused by restricted airflow (like a dirty filter) or low refrigerant.
What you can do:
Turn off the AC and switch the fan to “on.” This will help thaw the coils. Then check your filter and vents for any blockages. If the ice comes back, you may need a professional to inspect the system.
Refrigerant is what your air conditioner uses to move heat out of your home.
What happens:
If your system is low on refrigerant, it can’t cool effectively. You may also notice hissing sounds near the outdoor unit—this could mean there’s a leak.
What you can do:
Unfortunately, refrigerant issues are not a DIY fix. If you suspect low refrigerant, it’s time to call a licensed HVAC technician. On The Mark Heating and Air can check for leaks, recharge your system, and get your home cool again fast.
That big metal box outside your home? It’s called the condenser, and it’s essential for keeping your home cool.
What happens:
If the condenser coils are dirty or covered by plants, leaves, or debris, the unit can’t release heat properly. That forces your system to work harder, and it might stop cooling altogether.
What you can do:
Make sure there’s at least 2 feet of space around the outdoor unit. Use a hose to gently rinse off dirt (turn the unit off first). Don’t use a pressure washer; it can damage the fins.
Sometimes, your system just won’t turn on, or it starts and stops constantly.
What happens:
Capacitors, fuses, or relays can wear out over time. Tripped breakers can also shut your system down. These parts are essential to keep your AC running properly.
What you can do:
Check your home’s breaker box and reset any tripped breakers. If the AC still won’t start—or it keeps shutting off—call a professional. Electrical repairs can be dangerous without the right tools and training.
If your system is over 10–15 years old, or if it was never properly sized for your home, it may be struggling to keep up.
What happens:
Older systems lose efficiency and cooling power over time. Undersized systems run nonstop but still can’t reach your desired temperature.
What you can do:
It might be time to consider a replacement. A new high-efficiency system will cool your home faster, lower your energy bills, and come with modern features like zoning and smart thermostats. On The Mark Heating and Air can help you choose the best option for your home and budget.
If you’ve gone through this list and your AC still isn’t cooling, don’t wait for things to get worse. Some issues can damage your system if left untreated—and others might already be causing your energy bills to skyrocket.
That’s where we come in.
When it comes to AC maintenance and repair in Palatine, IL, no one does it better than On The Mark Heating and Air.
We offer:
Don’t let a malfunctioning AC ruin your summer. If your air conditioner isn’t keeping you cool, give the pros at On The Mark Heating and Air a call.
📞 Call now or schedule your service online—we’re here to keep Palatine cool, comfortable, and worry-free!
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