Ice on an air conditioner seems backwards, but it's common — and it'll stop your system from cooling. Here's what causes it.
First: turn it off and thaw
Cause 1: restricted airflow
The #1 cause. A dirty filter, closed vents, or a blocked return starves the coil of warm air, so it freezes. Replace the filter and open all the vents.
Cause 2: low refrigerant
A refrigerant leak drops the pressure and temperature at the coil until it ices over. This needs a pro to find and fix the leak — topping it off without a repair just delays the problem.
Cause 3: a dirty coil
A grimy evaporator coil can’t absorb heat properly and freezes. It also kills efficiency — one reason regular tune-ups pay off.
When to call us
If it freezes again after a fresh filter and a full thaw, the cause is usually refrigerant or the coil — call us for an upfront-priced diagnosis. More: AC not cooling?
Related:
AC Repair →
Maintenance & Tune-Ups →
AC Not Cooling? →