Why Is Your AC Freezing Up?
Your AC is freezing up because of restricted airflow (usually a clogged filter) or low refrigerant (which means there's a leak). These cause the evaporator coil temperature to drop below freezing, and ice builds up on the coil, refrigerant lines, or outdoor unit. Turn your AC off immediately - running a frozen system can destroy the compressor ($800-$1,800+ to replace). Here's exactly what to do right now and what's causing it. If your AC is running but blowing warm air without ice, that's a different issue.
Why It's Freezing: 5 Common Causes
- Blocked airflow: A clogged filter, closed vents, or blocked returns prevent warm air from reaching the coil. It drops below freezing and ice forms.
- Low refrigerant: A leak drops system pressure, which drops the coil temperature below the freezing point.
- Dirty coil: Dust and grime insulate the coil. It can't absorb heat properly.
- Blower motor failure: If the fan isn't pushing air, ice forms fast.
- Running AC below 60°F outside: Operating the system in cool weather can freeze the coil - this happens in early spring a lot.
Can a Frozen AC Damage the Compressor?
A frozen AC isn't just uncomfortable - it can destroy the compressor, which costs $800–$1,800+ to replace. When liquid refrigerant that should have evaporated reaches the compressor as a liquid, it causes internal damage called "slugging." It can crack valves and seals. Running a frozen system for even a few hours can turn a minor problem into a system-ending failure. This is why acting quickly matters. If the compressor fails, see how much a new AC costs before deciding.
What Should You Do Right Now If Your AC Is Frozen?
Turn your AC off immediately. Switch the fan to "ON" (not AUTO) - this blows warm air across the frozen coil and speeds up thawing. It usually takes 2–4 hours. Don't try to chip or scrape the ice off. While it thaws, check the air filter and replace it if it's dirty. Once fully thawed, restart and watch it closely for 30 minutes.
What If Your AC Keeps Freezing Up?
If the AC freezes a second time, the problem isn't the filter. You likely have a refrigerant leak or a mechanical failure that needs professional repair. Trouble Free provides thorough AC diagnostics and repair across the Peoria metro area. We find the root cause - not just the symptom. To keep your home trouble-free, call (309) 347-5309 before a frozen coil becomes a dead compressor. Want to know what AC repairs cost before you call? We break it down by repair type.