An air conditioner freezes up when the indoor coil gets too cold, usually because not enough warm air is moving across it or because the system is low on refrigerant from a leak. If you see ice on your refrigerant lines or indoor unit, turn the system off and switch the fan to On to thaw it, then find and fix the cause.
What to do right now
- Set the thermostat to Off and the fan to On
- Let the ice melt completely, which can take a few hours
- Place towels near the indoor unit to catch meltwater
- Check your air filter and replace it if it is dirty
- Make sure supply and return vents are open and unblocked
- If it freezes again, call us
Common causes
- Dirty air filterThe most common cause. A clogged filter restricts airflow across the coil.
- Low refrigerantCaused by a leak. Adding refrigerant without fixing the leak only delays the next freeze-up.
- Dirty evaporator coilDust buildup acts like insulation and reduces airflow.
- Blower problemsA failing blower motor or dirty blower wheel moves less air.
- Blocked returns or closed ventsToo little air coming back to the system.
Why it matters
A frozen coil cannot cool your home, and running the system while frozen can send liquid refrigerant back to the compressor, which can damage it. Catching the cause early usually means a smaller repair.
Related prices
| Service | Typical Price Range |
|---|---|
| Evaporator Coil Cleaning | $150–$500 |
| Refrigerant Leak Detection | $250–$700 |
| Refrigerant Leak Repair | $400–$1,500 |
| Blower Motor Replacement (PSC) | $400–$900 |
Typical ranges for guidance only; your exact price is given in writing before any work begins. See our full price guide.