It's 95 degrees outside, the humidity is brutal, and you walk to your air handler to find it coated in ice. It feels impossible — but a frozen AC coil is one of the most common service calls in South Florida, and it always means something in your system needs attention.
What You Should Do Right Now
First: turn the system to fan-only mode (or completely off) and let the ice melt. Running a frozen system risks burning out your compressor — an $1,800 to $3,000 repair. Give it 2 to 4 hours before turning cooling back on. Place towels around the air handler to catch drip-off. Once thawed, you can diagnose the root cause.
Cause #1: Restricted Airflow
Your evaporator coil needs a constant, strong flow of warm air passing over it to function correctly. When airflow is blocked — by a clogged filter, collapsed duct, closed supply vents, or a dirty coil — the refrigerant inside gets too cold because there's no warm air to absorb. Moisture in the air then freezes on the coil surface. Check your air filter first. If it's grey and thick with dust, that's very likely your culprit. Replace it, let the system thaw, and test again.
Cause #2: Low Refrigerant
When refrigerant levels drop due to a leak, the pressure in your system drops along with it. Lower pressure means the refrigerant evaporates at a much colder temperature than it should — cold enough to freeze the surrounding moisture in the air. Unlike a dirty filter, this is not a DIY fix. A licensed technician needs to locate the leak, repair it, and recharge the system to the correct pressure. Simply adding refrigerant without fixing the leak is a temporary measure that will leave you in the same situation within months.
How to Tell the Difference
After the system thaws, replace your filter and run the system again. If it freezes again within a day with a clean filter, refrigerant is almost certainly the issue. You may also notice the system running constantly without reaching your set temperature, or ice forming specifically on the refrigerant lines outside the unit. These are all signs pointing to a leak that needs professional diagnosis.
Kyzar Air Conditioning serves West Palm Beach, Port St. Lucie, and surrounding areas with same-day diagnostics. If your system keeps freezing, don't wait — a frozen coil left unaddressed will eventually damage your compressor.
