Turn the cooling off and run the indoor fan. A frozen coil is a symptom, usually of low airflow (filter, blower, closed or blocked vents) or low refrigerant from a leak, and running the system frozen risks the compressor, the most expensive part in the system. Let it thaw fully (hours, not minutes) before a technician tests it, because readings on a frozen coil lie. Do not chip the ice. If it freezes again after a filter change, the cause is refrigerant side or blower side, and that is a diagnosis visit, not another thaw.
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