Why Does My Air Conditioner Freeze Up?

Summer has arrived, and your air conditioning unit may be working at full tilt to keep your household comfortable. Proper maintenance is necessary to help your air conditioner handle the increased demands of summertime, or you may notice signs of distress in your unit. One of the most common HVAC problems that homeowners have during the summer is the unit freezing over with ice. If you’re dealing with this issue, we share a few of the most common reasons here. Ready to fix the problem so your AC is up for the challenges of warmer weather? Contact your local AC service to prevent your unit from freezing up.

INADEQUATE AIRFLOW

Poor airflow causes a host of issues, including the air conditioner icing up. When the unit isn’t receiving enough air, there won’t be enough warm air from within your home to prevent condensation on the coils from icing over. Dirty filters are a common cause of airflow problems, and this is an easy fix. If you’ve recently noticed ice on the unit, look at the filters first to be sure they’re clean. Other common causes are oversized units or undersized ductwork.

LOW LEVELS OF REFRIGERANT

In rare cases, low refrigerant may cause your unit to ice up. If left unresolved, this issue can lead to more serious problems, so it’s best to get in touch with your AC service if you notice ice or frost on your AC lines, or see water on the floor around your furnace during the off-cycle. Complications from low refrigerant may begin with pressure changes in the system, which in turn cause moisture to condense and freeze on the coils. A thick layer of ice will affect airflow and act as an insulator. The ice may start to melt, leading to a dripping sound (and, potential water damage). At this point, you’ll probably notice that the unit is no longer cooling effectively. It’s time to call an HVAC professional!

FAULTY BLOWER FAN

Your AC unit requires a precise balance of airflow and air pressure to function properly. When the blower fan is damaged, the air conditioner may freeze due to the absence of hot air. The blower fan is an essential component of the AC unit, as it keeps warm air moving into the unit. A broken fan will allow too much condensation to accumulate on the coils, and may also cause a refrigerant line to freeze.

SETTING THE TEMPERATURE TOO LOW

Setting the thermostat below 72 degrees can often result in freezing of the unit, as the colder air being pulled into the system doesn’t contain enough heat to keep the coil thawed out.  Additional components can be installed that will allow you to run your system colder without fear of freezing if very low temperatures are required.

If you’ve noticed that your AC keeps freezing up, be sure to shut off the unit immediately and keep an eye out for water leaks. Wait for the ice to melt and avoid chipping off the frost, as this may damage crucial components of the system. After about an hour, run the fan to encourage airflow. If freezing problems persist, reach out to an experienced AC service. When you’re in need of HVAC service (including after-hours and emergency repair) in the Front Range area, we’re here to help. Please contact our team today to schedule your appointment.