I have the unit put in about 1 year,but few week ago it keep get frozzen ice on the pie,the a/c man used to put the unit come and check 4 time and he said the freon is good,but he still doesn't know what happen,when happen I try cut off the A/C let the fan run to melted the ice for 30 minutes then let it run back I can fell the cold air going out the vent,but the happen kepp repeat like evry 3 ,4 day like that.Is anybody see this happen before please help me... THANK YOU VERY MUCH FOR YOUR HELP

You have a dirty air filter

OR

Blocked return air or discharge air grills. (open up all registers)

OR

Was the indoor coil replaced when the outside unit was?

If not that could be the problem.

A incorrect refrigerant charge can also cause this problem.