Why Is There Ice on My Air Conditioner?

It’s hot outside, so why is there ice on your air conditioner? This problem has many potential causes, and all of them are signs of trouble. So first things first—if your air conditioner is frozen, shut off the unit and let it start defrosting while you learn more about why this happened and whether you need to call an AC repair technician in Fort Collins.

How Do I Know If There’s Ice on My Air Conditioner?

Ice doesn’t form on an AC unit’s exterior condensing unit, so that’s the wrong place to look. Instead, take a peek at the evaporator coil near the furnace. When everything is working properly, this is where the air conditioner extracts heat from your indoor air as it blows over the refrigerant-filled coils.

But when something is wrong, the heat transfer process is interrupted, and the cold refrigerant freezes the moisture in the air around it. The resulting ice buildup prevents any heat transfer from occurring at all, so the AC starts blowing hot air. Depending on the cause, you may also hear the air conditioner running but feel hardly any air flowing from the vents.

If you continue to run the AC unit or attempt to chip away at the ice, you could cause even more damage. That’s why shutting off the air conditioner and requesting a repair is the best thing to do. While you wait, you can point a hairdryer at the ice to speed up the melting process without harming the evaporator coils.

What Causes Ice Buildup on an Air Conditioner?

Several reasons could be to blame for your frozen air conditioner. Here are some possibilities:

• Low refrigerant: Air conditioners have a closed refrigerant loop, but leaks can develop over time. Low refrigerant can cause the evaporator coils to get too cold, causing ice to build up. A professional can locate and fix refrigerant leaks and recharge the system to the optimal level.
• Dirty coils: A layer of dirt on the evaporator coils affects the heat transfer process. This not only raises your energy bills but can also prevent the refrigerant from absorbing enough heat, causing the coil to freeze.
• Clogged filter: The warm air from your home must flow over the evaporator coils fast enough to prevent the condensation on the coils from freezing before it drips into the drain pan below. One major cause of poor airflow is a dirty air filter. Change the filter to improve airflow and hopefully stop the AC from freezing.
• Closed supply registers: This is another cause of insufficient airflow. Check that no more than one out of five air vents are closed throughout the house. Otherwise, the imbalanced airflow could cause the air conditioner to ice up.
• Malfunctioning fan: Check that the fan is rotating when you turn on the air conditioner and that it’s also spinning fast enough. A technician can adjust the fan speed if needed to improve air circulation and fix your freezing problem.
• Nighttime use: If you run your air conditioner when it’s too cold outside, it’s more prone to icing up. Have your thermostat checked and recalibrated if needed to make sure the temperature reading isn’t faulty. Then, consider opening your windows on cool summer nights when the temperature drops into the 50s rather than running the AC.
• Drainage problems: Air conditioning removes both heat and humidity from the air before circulating it back into your home. Colorado has a dry climate, but water can still build up in the condensate drain during particularly humid weather. The freezing effect could then extend down into the drain, exacerbating the situation further.

A Note About Ice Buildup on a Heat Pump During the Winter

If you use a heat pump for year-round climate control, be aware that ice buildup on the outdoor condensing unit is normal in our climate. Feel free to brush off any deep snow that accumulates, but rest assured that the system has a built-in defrost mode. This temporarily sends heated air to the outdoor unit as needed to melt the ice. Of course, if defrost mode isn’t working right, ice and snow many continue to accumulate, affecting performance in the process. If you see this happening, schedule heat pump repair right away.

Air Conditioning Repair in Fort Collins

If you have a frozen air conditioner, it’s important not to simply turn the unit back on after melting the ice. The coils will simply freeze again until you address the underlying problem. Allen Service offers fast, efficient, and affordable air conditioning repair in Fort Collins. Our team is just a call away, so let us know how we can help! Reach us at 970-672-1660 or contact us online to request the services you need.