Turn cooling off
Stop the cooling call. If safe and the blower operates normally, fan-only mode can help thaw the coil.
Protect against water
Watch the drain area and protect nearby flooring or belongings as the ice melts.
Check accessible airflow items
A dirty filter or blocked return may contribute, but other causes require testing.
Do not add refrigerant blindly
Low refrigerant is only one possible cause and indicates a leak or other issue that should be diagnosed.
When to request professional service
Request service when basic settings and an accessible filter do not explain the problem, or when the system is frozen, leaking, electrically unstable, unusually noisy or unable to maintain a safe indoor temperature.
Shut the system down for smoke, a persistent burning smell, repeated breaker trips, spreading water or severe mechanical noise. Call emergency services for fire, medical danger or another immediate threat to life or property.