Why Your AC Might Not Be Cooling Properly After Winter

When you switch your thermostat from heat to cool after a long winter, you expect it to turn on without incident. However, this doesn’t always happen. After sitting all winter, your AC might not kick back into action as smoothly as you’d like. It might only blow warm air, struggle to cool your home evenly, or may not turn on at all. If your AC is not cooling properly after winter, it doesn’t necessarily mean you need an entirely new system. In many cases, the problem is a simple fix.  

At Maximum Heating & Air Conditioning in Aurora, Illinois, we understand the frustration of discovering a non-working AC unit after winter. Fortunately, our team is equipped to help you diagnose and resolve the issue quickly, efficiently, and affordably. Let’s walk through some of the most common reasons your AC might be underperforming after a long winter break. 

Dirty or Clogged Air Filters 

One of the most common and easily overlooked reasons your AC isn’t cooling properly is a dirty air filter. During the off-season, dust, dirt, pet hair, and other debris can build up in the filter, especially if your system hasn’t been checked in a while. 

When the filter is clogged, it restricts airflow, making it harder for your AC to push cool air through your home. This not only reduces cooling efficiency, but also forces your system to work harder, which can lead to higher energy bills and unnecessary wear and tear. 

Ideally, you should check your air filter every month, especially before the cooling season begins. If it looks dirty or clogged, replace it. If your filter is reusable, give it a good cleaning with water and let it dry completely before reinstalling. 

Low Refrigerant Levels 

Refrigerant is the lifeblood of your air conditioning system. It’s what actually removes heat from the air inside your home and carries it outside. If your AC is low on refrigerant, it simply can’t cool the air effectively, no matter how hard it runs. 

Even though your system hasn’t been in use during winter, refrigerant can still slowly leak out through small cracks or loose connections. These leaks can go unnoticed until you try to use the AC and realize it’s blowing warm air or struggling to maintain a comfortable temperature. 

Some of the most common signs of low refrigerant include: 

• Warm or slightly cool air coming from the vents. 

• Hissing or bubbling sounds near the AC unit. 

• Ice buildup on the refrigerant lines or evaporator coil. 

• Longer cooling cycles than normal. 

If you suspect a refrigerant issue, it’s best to call a professional. Refrigerant handling requires special tools and certification, and a technician can safely locate and repair the leak before recharging the system. 

At Maximum Heating & Air Conditioning, we make it easy to maintain the condition of your AC unit by offering reliable and effective maintenance services. Our NATE-certified technicians are expertly trained to deliver exceptional HVAC services, including routine filter changes and thorough inspections of your cooling system. Also, ask about our special offer on air conditioner tune-ups. 

Thermostat Issues 

Sometimes the problem isn’t with your AC unit at all, but rather the thermostat that controls the system. After months of disuse, settings my have accidentally changed, or if your thermostat runs on batteries, they might have died during the winter. 

A miscalibrated thermostat can misread the room temperature, causing your system to run too little, or not at all. Even a few degrees off can make a noticeable difference in comfort. If you’re using a smart thermostat, it may need to reconnect to Wi-Fi, update firmware, or be manually switched from heating to cooling mode. 

Some quick fixes to consider include: 

• Replace the batteries if you have a battery-operated thermostat. 

• Double-check the mode and temperature settings. 

• For smart thermostats, restart the device or reconnect to Wi-Fi if needed. 

If problems persist, the thermostat itself may need to be professional recalibrated or replaced.  

Blocked or Dirty Condenser Unit 

Your AC’s condenser unit, the large box usually located outside, plays a crucial role in releasing the heat pulled from your home. But after months of winter weather, it’s common for the unit to become clogged with leaves, twigs, dirt, or even leftover snow and ice.  

When airflow around the condenser is blocked, the unit can’t expel heat efficiently, forcing your system to work overtime with poor results. This can lead to warm air inside, higher energy bills, and potential damage over time. 

Things you can do to try and resolve this issue include: 

• Gently clear away any visible debris, leaves, or dirt around the unit. 

• Make sure there’s at least two feet of clearance on all sides for proper airflow. 

• Avoid using a pressure washer; lightly hose it off from the inside out. 

If the unit looks particularly dirty or you suspect deeper blockages, it’s a good idea to have a technician clean the coils and check for any hidden issues. 

Tripped Breakers or Electrical Problems 

If your AC won’t turn on at all after the winter, it could be something as simple as a tripped breaker or blow fuse. During the colder months, power surges or weather-related issues might have affected your home’s electrical system without you even noticing.  

Your AC unit draws a significant amount of power, and if it tries to start up while something’s wrong, like a dirty filter or blocked condenser, it can trip the breaker as a protective measure. 

Some things to check include: 

• Go to your electrical panel and look for any tripped breakers.  

• If you see one, flip it fully off, then back on. 

• Also check any dedicated AC disconnects, usually located outside near the unit, if it is accessible and safe to do so. 

If the breaker trips again soon after resetting, don’t keep flipping it. This could be a sign of a more serious electrical issue. In that case, call in a licensed HVAC technician or electrician to diagnose the problem. 

When more complex HVAC problems arise, home and business owners are often concerned about how they’ll afford the services they need to fix their systems. Maximum Heating & Cooling is dedicated to offering fair and upfront pricing, as well as several money-saving HVAC discounts and coupons.

Frozen Evaporator Coils 

Even in warmer weather, your AC can freeze up. The evaporator coils inside your indoor unit are responsible for absorbing heat from your home’s air. But when something disrupts this process, such as blocked airflow, a dirty coil, or low refrigerant, those coils can get too cold and freeze over. 

When ice forms on the coils, your AC can’t effectively absorb heat, meaning it’ll blow warm or barely cool air. You might also hear unusual sounds like hissing, bubbling, or even clicking as the unit struggles to operate. 

Common signs of frozen coils include: 

• Ice or frost buildup on the outside unit or refrigerant lines. 

• Reduced airflow from vents. 

• Warm air or no air coming from the system. 

• Strange noises. 

If you suspect that you have frozen coils, turn off the AC immediately to prevent further damage. Allow the system to completely thaw, which can take several hours. Replace or clean the air filter, and check for blocked vents. Once it’s completely thawed, turn the system back on and see if the problem returns. 

Ductwork Leaks or Blockages 

If your AC seems to cool some rooms better than others, or not at all, the problem might be hiding in your ductwork. Leaky or blocked air ducts are a commonly overlooked cause of uneven or poor cooling, especially after months of disuse during winter.  

Over time, temperature fluctuations, pests, moisture, or simple aging can cause ductwork to crack, disconnect, or fill with debris. When that happens, the cool air your AC works hard to produce never fully reaches your living spaces. 

Signs of ductwork problems include: 

• Some rooms are warmer or cooler than others. 

• Weak airflow from vents. 

• Higher-than-usual energy bills. 

• Whistling or rattling noises from behind walls or ceilings.  

If you believe that the ductwork is causing your unit not to work properly, start by inspecting visible ducts for loose connections or damage. Make sure that the vents are open and unobstructed. Consider having a professional do a pressure test or thermal scan to detect hidden leaks. 

Keeping your home cool and comfortable during the spring and summer is a top priority. At Maximum Heating & Cooling, we offer a variety of affordable financing options to make it easy to get the services you need. In addition to accepting cash, PayPal, and most credit and debit cards, homeowners can apply for Wisetack Financing, which offers zero down payment, no annual fee, and low monthly payment plans. 

Lack of Regular Maintenance 

One of the most preventable reasons your AC unit isn’t cooling properly after winter? Skipping regular maintenance. Like any machine, your air conditioner needs occasional attention to keep running smoothly, especially after months of inactivity. 

Without annual tune-ups, small issues like dirt buildup, worn parts, or refrigerant imbalances can go unnoticed until they turn into costly problems. Routine maintenance helps catch these early, keeping your system efficient and extending its lifespan. 

A few reasons why annual maintenance matters include: 

• Ensures peak performance before the heat hits. 

• Prevents unexpected breakdowns. 

• Helps maintain energy efficiency and lower bills. 

• Keeps our warranty valid. 

A typical AC tune-up involves a series of tasks, such as cleaning coils and draining lines, checking refrigerant levels and pressure, and inspecting and tightening electrical connections. The process may also involve lubricating moving parts, testing thermostat accuracy, and replacing or cleaning air filters. 

Your AC Not Effectively Cooling? Call the Team at Maximum 

If your AC isn’t cooling properly after winter, don’t wait for the summer heat to hit before addressing the issue. From dirty filters to refrigerant leaks, there are several common causes of post-winter AC troubles, and most of them can be fixed with a little attention.  

At Maximum Heating & Air Conditioning, we have been serving home and business owners in the Auroa, Illinois area for more than 20 years. Our team offers a full range of HVAC services, including heating, air conditioning, humidity, and air quality, ensuring that your home or business remains cool and comfortable. If your AC is not cooling properly after winter, call our office today at (630) 788-4688 to see how we can help.