How to Handle Frozen AC Coils

Handling frozen AC coils is crucial to prevent damage to your air conditioning system and restore proper cooling. Here’s a step-by-step guide on how to address frozen AC coils:

1. Turn Off the AC

Safety First: Turn off the AC system at the thermostat to prevent further cooling and allow the coils to thaw naturally.

2. Identify the Cause

Check Airflow: Insufficient airflow caused by dirty air filters, blocked vents, or closed registers can lead to condensation buildup and freezing of the evaporator coils.
Refrigerant Issues: Low refrigerant levels or leaks can also cause the evaporator coil temperature to drop below freezing.

3. Thaw the Coils

Wait for Thawing: Allow the coils to thaw completely. This may take several hours depending on the extent of the frost or ice buildup.
Use Fans: To expedite the thawing process, you can run the fan setting on your thermostat without cooling mode.

4. Inspect and Clean Filters

Check Filters: Inspect and replace dirty or clogged air filters. Clean reusable filters according to manufacturer instructions. Clean filters ensure proper airflow and prevent future coil freezing.

5. Clear Air Vents and Registers

Remove Obstructions: Ensure all air vents and registers are open and unblocked. Improving airflow helps prevent condensation buildup on the coils.

6. Check and Clean the Coil

Inspect the Coil: Once thawed, inspect the evaporator coil for dirt, dust, or debris. Use a soft brush or vacuum cleaner to gently clean the coil surfaces.
Professional Cleaning: If the coil is heavily soiled or difficult to access, consider scheduling professional coil cleaning with an heat pump installation technician.

7. Address Refrigerant Issues

Refrigerant Levels: If low refrigerant levels are suspected, contact a licensed HVAC technician to inspect for leaks, repair any leaks found, and recharge refrigerant to manufacturer-recommended levels.

8. Verify Thermostat Settings

Correct Settings: Ensure the thermostat is set to a temperature that prevents the evaporator coil from freezing. Avoid setting the thermostat too low, especially in humid conditions.

9. Ensure Proper Insulation and Sealing

Ductwork Inspection: Inspect ductwork for leaks or gaps that may contribute to inadequate airflow and coil freezing. Seal any leaks with mastic sealant or duct tape.

10. Schedule Preventive Maintenance

Regular Service: Schedule annual maintenance with an HVAC professional. Regular maintenance includes inspecting and cleaning coils, checking refrigerant levels, and ensuring all components function efficiently.

11. Monitor Performance

Observation: After addressing the issue, monitor the AC unit for several cooling cycles to ensure proper operation and no recurrence of freezing coils.

By following these steps and addressing the root causes of frozen AC coils promptly, you can prevent further damage to your HVAC system and ensure reliable cooling performance throughout the hot months. Regular maintenance and attentive monitoring are key to maintaining the efficiency and longevity of your air conditioning system.