Ok this has been going on for 2 years now, thought It was just a filter issue since it comes and goes. When the Furnace/Heat Pump is set to 'heat' during the winter/cold days everything works great. However soon as the hot days come and you set it to 'Cold' that's when we have problems. It doesn't put out any cold air and starts making a crackling sound especially when you turn it off it makes loud crackling sounds. After leaving it off for about 3-6 hours you can turn it on and it works fine for a couple days then it does it again without fail and there is the sound of dripping/running water that can occasionally be heard. Why is it making this cracking sound and not putting out the cold?

Sounds like your unit is freezing up. How is your air filter clean? You may need some freon

sounds like your unit is freezing up. How is your air filter clean?? You may need some freon

Actually the air filter needs changed once a month and is really dirty. Someone mentioned something but if the Air Filters aren't good the dust will get through and stick to something and cause it to freeze up, is that true?

Well if you run your unit with out a filter the dust and dirt then will stick to the coil. The unit will feeze due to lack of air flow , so if your coil, or air filter is blocked enough that not much air can go threw the coil will start to ice.