No, ice on your air conditioning system doesn’t mean the AC is working extremely well. It means the opposite. Ice isn’t supposed to form on an air conditioner under normal conditions. Unfortunately, people often ignore this sign of an AC malfunction because it seems like it makes sense—and this can soon lead to an air conditioner that isn’t providing any cooling at all!
What can happen with an AC that causes ice to form? There are several potential causes, and most are connected to the evaporator coil. This coil contains the cold refrigerant that absorbs heat from the air around it to cool it down. As the cold refrigerant evaporates, it warms up. If something prevents the refrigerant from warming up enough, it will remain below freezing. The water moisture that forms along the coil will then start to freeze. Once ice begins to form, it will further restrict the evaporator coil from absorbing heat until the coil is completely frozen over and the AC won’t work at all.
Here are the main causes of ice development:
If you’ve looked at the cabinet underneath your kitchen sink and discovered water damage or water pooling, then you’ve got a plumbing problem. It may be something simple, or you may need to call upon the help of an experienced 
