Hello, the line from the central air unit keeps freezing. The fan from both the unit and the furnace come on, but after an hour or so it has a weak flow (barely cool) and I have to turn it off to defrost. I wonder if I need a thicker insulated cover? Any ideas? Thanks!

3 things will make unit freeze. 1) lack of air flow.Diry coils, dirty filter or fans not coming on. 2) low on refrigerant. 3) a restriction.

First I would check the filter in return. Is it clean and installed properly? Is the coil outside? Is it free of grass clippins, leaves etc?

The unit is about 2 to 3 feet away from any shrub or grass. I change the filter every 2 months , sometimes every month depending on how dirty it is. Yesterday morning it was blowing at full capacity, towards the afternoon is when it started freezing. It sounds like I need to check it for a restriction. Thanks!