As hot as it gets in summer, you wouldn’t expect frost to form on anything and especially not on machinery such as an air conditioner that has been working hard day and night. However, that can and does happen, and it leaves you sweating in a hot home. Here are situations that lead to a frozen air conditioner and what to do about it.
Cause #1: Restricted Airflow
Air conditioners rely on good airflow to do their job correctly. When air is restricted, the evaporator coils drop below the freezing point and ice begins to form on them. Common causes of restricted airflow include:
- Clogged air filters— Air filters play an exceptionally important role in keeping the system and your indoor air clean. When filters are filthy, your air conditioner struggles to get enough airflow over the coils. Along similar lines, it could be that you are using a type of air filter your system wasn’t designed for. Ask your HVAC contractor about filter types that allow adequate airflow to your A/C.
- Malfunctioning blower motor— Your HVAC technician can inspect the motor to see if this is the case. The motor could be failing or it could simply be it isn’t set at the correct speed.
- Blocked supply registers— Make sure all supply registers are open and that nothing is blocking them.
Cause #2: Dirty Coils
Dirty coils can also cause a frozen air conditioner because a layer of grime interferes with normal heat exchange, allowing coil temperature to drop. Most evaporator coils need cleaning on occasion, and your technician can do this as a component of your annual A/C checkup. Dirty air filters can contribute to the problem, however, so don’t put off changing them.
Cause #3: Low Refrigerant
If this is the cause, then your technician will need to check for leaks. When faced with a refrigerant leak, it can be wise to upgrade to a new air conditioner.
Please visit our Valley Heating, Cooling, Electrical website for in-depth information on most HVAC topics, or give us a call at (408) 868-5500.
Our goal is to help educate our customers in the South Bay Peninsula and Santa Cruz areas of California about energy and home comfort issues (specific to HVAC systems).