Ice on the indoor coil means the coil is getting too cold for the air moving across it - and that's only ever two families of cause: not enough airflow, or not enough refrigerant. One is often a filter you can clean today; the other is a service call. Never chip ice off - fins bend and coils puncture.
First: thaw it properly
Power off at the remote, run FAN-only if available (speeds melting), or just power down at the breaker. Towels under the unit. Full thaw can take a few hours - restarting a half-thawed unit just re-freezes it and risks slugging liquid to the compressor.
Safe checks (after full thaw)
- Filters. The number-one cause. Clean them, restart, watch for frost at the coil edges over the next hour of cooling.
- Vents and coil face. Blocked louvers, furniture against the unit, or a dust-matted coil face all starve airflow. Gentle vacuum with a brush attachment on visible surfaces only.
- Fan actually running? If the indoor blower is weak or silent while cooling runs, stop - fan motor diagnosis is a technician job (and explains the freezing by itself).
- Running cool in cold weather? Cooling mode at low outdoor temperatures (server rooms, shoulder seasons) drives coil temps below freezing on many standard units. Check your model's minimum cooling ambient in our database; below it, freezing is expected behavior - the fix is a low-ambient-capable unit or controls, not repair.
If it re-freezes with clean filters and clear airflow
That's the refrigerant family: undercharge from a slow leak drops coil pressure and temperature until ice forms. A2L refrigerants (R-454B, R-32) are certified-handling only - the useful call is "find and fix the leak," not "top it up." Pair this with our not-cooling page symptoms and any error code on the display before phoning - EL 0C-class codes confirm the diagnosis on many units.
Sources
No model-specific systems are linked from this guide yet.