During hot weather conditions or warmer seasons, you might look out your window and see that there is ice forming on your air conditioning system, sometimes even inside the unit. Ice can develop for many reasons. If you notice any ice on or in your air conditioner, it is best to call a professional to do an inspection and see if the system has any problems, such as the following:
The air filter is located inside of your home and is housed within the air handler. When the filter becomes filled with dust and debris, air cannot properly pass through it. The obstruction of airflow causes the outdoor condenser to become too cold because the warm interior air is not able to go through it. Ice can form anywhere on the exterior unit. Cleaning or replacing the air filter can solve this problem.
A refrigerant leak is another reason for ice formation on the exterior part of an air conditioner. The ice may develop on the evaporator's coil or on the suction line, which is a long hose that connects the outdoor unit to the air handler inside of your house. When the refrigerant leaks, its level becomes low. One part of the coils or lines becomes colder than the other, causing ice and icicles to form.
Debris and obstructions around the outdoor unit may also cause ice to form. This happens because the debris blocks air flow from around the unit. When the warm air cannot pass over the cool coils, it causes ice to form. Dead leaves, overgrown grass or shrubs, twigs, and tree limbs can all obstruct the fan blades. Other problems with the fan, such as a bent blade, electrical short or worn out motor, can also cause ice to form.
What Causes Ice to Form on an Air Conditioner?, Geeks on Home