It might seem like a strange sight during a sweltering Pennsylvania summer, but seeing a layer of frost or a solid block of ice on your outdoor unit is a major red flag. While it may look like your system is working overtime to keep you cool, ice buildup is actually a sign of a significant internal struggle that can lead to a complete system failure. If you spot frozen coils, the first thing you should do is turn the system off at the thermostat and have a professional AC repair service inspect it to prevent permanent damage to your compressor.
At Shearer Heating, A/C & Refrigeration, we have spent over 75 years helping our neighbors in Washington and the Greater Pittsburgh Area navigate these cooling crises with speed and expertise.
5 Common Reasons Your AC is Freezing Over
Understanding why your system is struggling is the first step toward restoring your home’s comfort. Here are the top five reasons we see ice forming on air conditioning units in our local community.
1. Restricted Airflow from Clogged Filters
The most common culprit is simply a lack of air. When your air filter is coated in dust and debris, it prevents warm air from reaching the evaporator coils. Without that warmth to absorb, the coils drop below freezing, turning the moisture in the air into ice.
2. Low Refrigerant Levels or Leaks
Your system relies on a specific amount of refrigerant to transfer heat. If there is a leak, the pressure within the coils drops, causing them to become much colder than they should be. As a Carrier Factory Authorized Dealer, our technicians are trained to find these leaks rather than just adding more refrigerant.
3. Clogged Condensate Drain Lines
As your AC cools the air, it also removes humidity. This moisture usually drains away through a small line. If this line is clogged with algae or debris, the water can back up and freeze right on the coil, eventually turning into a solid block of ice.
4. Malfunctioning Blower Motors
If the fan that blows air through your vents is sluggish or broken, there isn't enough air moving across the coils to keep them warm. This mechanical failure can quickly lead to a freeze-up and is often identified by a lack of airflow from your registers.
5. Dirty Evaporator Coils
Over time, dust can bypass your filter and settle directly on the coils. This layer of grime acts as an insulator, preventing the refrigerant from efficiently absorbing heat. This imbalance causes the coil to overcool and freeze any humidity that comes into contact with it.
Get Your Cooling Back on Track Today
When ice starts to form, every hour the system runs puts your compressor at risk of a total burnout. Our NATE-certified experts are available 24/7 to diagnose the root cause and ensure your system is operating at peak efficiency. We pride ourselves on clear communication, so you’ll always know exactly what is wrong and how we plan to fix it.
Whether you need an urgent diagnostic visit or want to prevent future issues with our Big On Service maintenance plan, Shearer Heating, A/C & Refrigeration is ready to help. You can reach our team at (724) 932-6862 to schedule a visit and get your home back to the cool, comfortable sanctuary it should be. Since 1948, we have been the name Pittsburgh trusts for honest, high-quality HVAC solutions.