Finding ice on your air conditioning unit might be confusing, especially on a hot summer day. The presence of ice or frost on the AC components can cause severe mechanical problems. Luckily, there are a few simple explanations for why this problem occurs. Use this guide to learn more about this issue and how an HVAC professional can help.

Restricted Airflow

The air conditioning unit draws in warm air and passes it over the evaporator coil to produce cool air. In a well-functioning unit, there’s plenty of air for this process to occur without any issues.

However, when the supply of warm air is restricted, the refrigerant inside gets too cold and causes the coil to freeze over and produce ice. Possible causes for this problem include:

• Dirty evaporator coils
• Problems with the blower fan
• Clogged filters
• Collapsed or leaking air ducts
• Blocked or closed vents

To prevent restricted airflow, rearrange the furniture and curtains to give the vents at least 18 inches of space. This will ensure that no obstructions are preventing proper intake. 

If you’ve discovered ice in the AC unit, turn it off immediately. Then, turn on the thermostat’s fan setting. The fan can run independently from the air conditioner itself, so leave it running for three to four hours to replenish the warm air circulating through the system and thaw the ice on the coils.

Low Refrigerant

The air conditioning unit relies on refrigerant to cool air before it’s distributed throughout the home. Low refrigerant levels prevent the house from staying cool. They also cause the unit’s coolant pressure to drop, resulting in a lower temperature and ice buildup on the appliance.

The refrigerant in the air conditioning unit is held inside a closed system. It isn’t used as the unit runs, so the only cause for lower levels is a leak. Besides ice, other signs of a refrigerant leak include:

• Abnormally high energy bills
• Hissing or bubbling noises
• Warm air coming from the vents

If you detect these signs, turn off the cool air and run the thermostat fan for several hours to thaw the components. A leaky refrigerant line can only be repaired by a qualified HVAC contractor. The liquid is toxic, and the line should be sealed and refilled with care to prevent health issues.

 

If you’ve noticed ice on your air conditioning unit, schedule a visit from Marvin's Heating & Air Conditioning in San Marcos, TX. This reliable family-owned business has provided dependable HVAC repairs, maintenance, and installations to residents of Hays County for nearly 40 years. Call (512) 396-4791 to schedule an appointment, or visit them online to learn more about their services.