How to tell if your coil is frozen?

How to tell if your coil is frozen in AC system has several visible and performance signs you can check without special tools. First sign is reduced or no cool air coming from vents even though system runs, and house not cooling. Second, check evaporator coil located in indoor air handler or above furnace, remove access panel after turning off power, if you see white ice, frost, or snow covering copper tubes and fins, coil is frozen. Third, look at refrigerant lines, large insulated suction line leading to outdoor unit may be covered in ice or frost when it should only be cool and sweaty. Fourth, outdoor unit may have ice on it in cooling mode which is abnormal, or indoor unit may have water dripping and overflowing drain pan when ice melts. Fifth, you may hear hissing or bubbling, or system runs continuously. Sixth, airflow from vents may be weak due to ice blocking coil. If you suspect frozen coil, turn system off and set fan to ON to thaw, check air filter for dirt blocking airflow, and look for causes like low refrigerant. Do not chip ice.