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AC Freezing Up
in Sioux Falls, SD
A frozen AC unit sounds strange in summer, but it happens all the time in Sioux Falls. When airflow drops or refrigerant runs low, the indoor coil gets too cold and moisture in the air freezes right onto it. The ice block grows until air cannot pass through at all, and then the system either shuts off or the compressor overheats.
Quick Answer
AC units freeze when airflow is blocked or refrigerant is low, and both problems are common in Sioux Falls homes. Ice on the coil means the system cannot move heat and will eventually shut down on its own. Shut the unit off and let it thaw completely before calling for service. Call (605) 231-9370 so a technician can find the cause before you turn the system back on.
Telltale Signs
Warning Signs to Watch For
- Visible ice on the copper refrigerant line coming out of the indoor unit
- Ice coating the indoor evaporator coil behind the air handler
- Water dripping or pooling around the indoor unit as ice melts
- Little to no airflow from the vents even though the system runs
- The outdoor unit runs fine but nothing happens inside
Root Causes
What Causes AC Freezing Up?
Restricted Airflow from Filter
A clogged air filter chokes off the air moving across the indoor coil. Without enough warm air flowing over it, the coil drops below freezing and ice forms fast. In Sioux Falls, homes with dogs, older ductwork, or return vents near the floor collect dust quickly and need filters changed every 30 to 60 days in summer.
The Fix
Filter Replacement and Airflow Check
Replace the filter and check every supply and return vent in the house to make sure none are blocked by furniture or closed off. The system needs unrestricted airflow to every room to keep the coil temperature stable.
Low Refrigerant from a Leak
When refrigerant is low, pressure inside the coil drops and the coil temperature falls well below freezing. Moisture from the air freezes onto the coil surface and builds up quickly. Many Sioux Falls homes have systems that are 10 to 20 years old, and older refrigerant lines and fittings develop small leaks over time.
The Fix
Leak Repair and Refrigerant Recharge
A technician uses leak detection equipment to find where the refrigerant is escaping, repairs the connection or line, and then recharges the system. Adding refrigerant without fixing the leak just delays the same problem.
Self-Diagnosis
Which Cause Applies to You?
Check the signs you're observing to narrow down the likely root cause before your inspection.
| What You're Seeing | Restricted Airflow from Filter | Low Refrigerant from a Leak |
|---|---|---|
| Ice appears right after changing a very dirty filter | ||
| Airflow from vents is weak even with a clean filter | ||
| System keeps freezing up even after thawing and restarting | ||
| Several vents in the house are blocked or closed off | ||
| Water puddles under the indoor unit after each freeze |
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