AC coils freeze when the evaporator coil gets too cold and moisture in the air turns to ice on its surface. The usual triggers are restricted airflow from a dirty filter, low refrigerant, a failed blower fan, or a clogged condensate line. Once ice forms, your air conditioner blows warm air and strains the compressor if it keeps running.
In Stockton and the Central Valley, a frozen coil almost always shows up in the middle of a hot, dry summer – right when you depend on your AC the most. A few causes, like a clogged filter, are easy to check yourself, while others, such as a refrigerant leak or a bad fan motor, need a licensed technician. Below we cover what makes coils freeze, the warning signs, and how to fix and prevent it.
Frozen AC Coils
Frozen AC coils is a common home related issue which can cause major problems for your home’s HVAC system. As summer temperatures in California stretch even longer, it would be a bad time for your air conditioning unit to fail and require repairs. With proper maintenance and monitoring to ensure warning signs are caught early, AC coil freezing should be kept to a minimum. However, if your AC unit does not get regular care and inspection, frozen coils could become a recurring issue that will shorten the lifespan of your HVAC system. Call today to get a technician out for a quick inspection!
Wondering Why Your AC Coils Are Frozen?
Understanding how an air conditioning unit works makes troubleshooting frozen AC coils easier. That said, it’s important to know that these coils are meant to be kept cold enough to remove the heat from the air that passes through them but not cold enough where it would freeze. If the coils start to freeze, the formation of ice will continue until the coils are completely encased. This causes mechanical failures in other parts of the HVAC system like the fans and compressor which must work harder with one part of the system failing and burdening the rest.
What Causes an AC Coil to Freeze?
AC coils will freeze for several reasons: the most common being airflow, refrigerant levels, and mechanical failure.
- Air filters are too dirty and are suffocating the HVAC system. Air conditioners need a healthy flow of clean air to effectively cool the temperature. If a system has poor circulation, the coils will start to freeze.
- Fan is broken and not circulating air properly. If the fan pulling air through the AC unit has failed due to a motor problem or broken fan blade, the coils will not have any airflow and will start to freeze.
- Blocked condensate lines introduce water around evaporator coils causing the water to freeze. Condensate lines draw away excess water accumulated from condensation. This is usually discharged, but if the line is blocked, the trapped water will generally freeze by the evaporator coils. This causes the water overflow to also freeze around the coils.
- Broken thermostat may cause AC unit to overwork which could cause AC coils to freeze over time. If the AC thermostat fails to identify the correct temperature, it can accidentally run for far longer than necessary. This could cause a system to gradually freeze over without any down time to let ice build up melt.
- Leaking refrigerant can result in inability to extract heat properly causing coils to freeze. Without refrigerant to help regulate the pressure and temperature, heat wouldn’t be extracted. A change in pressure will absorb too much heat allowing the coils to freeze.
- Dirty evaporator coils prevent optimal heat absorption. If they become too dirty, there is a good chance this could cause the coils to freeze. The coils will benefit from occasional cleaning to ensure that the coils are kept free of debris.
Signs of a Frozen AC Coil
No matter what the cause is, the impact it has is that your AC’s performance suffers. A few good indicators that you have frozen AC coils are:
- AC unit doesn’t pump cold air
- Restricted or weak air flow
- Ice is visible on any component of the AC unit
- Visible moisture around your AC unit
Troubleshooting Frozen AC Coils
If you have diagnosed your AC problem and determined it to be frozen coil related, there are a few things that you can do to troubleshoot your situation.
- Check & replace air filter if necessary. Dirty air filters can clog an AC unit and prevent the proper airflow necessary to keep the system working optimally.
- Turn thermostat off and allow system to thaw for several hours. Sometimes this is all that is necessary to allow ice to break down. This method may result in a mess if the coils have frozen to the point of being completely encased in ice. However, it is critical to ensure that the system doesn’t run while frozen to prevent compressor failure.
- If a defrost or thaw mode exists, use that and follow any instructions for dealing with ice.
- Whatever you do, DO NOT attempt to chip away at the ice because there is a chance that the coils could be damaged or punctured in the process.
How Do You Fix a Broken AC Coil?
If the steps above didn’t help your AC output problems, it may be time to call some professional help. During our inspection, we will check your system and make recommendations for repair. Our services include:
- Coil cleaning: Coils covered in debris prevent optimal heat exchange which eventually leads to ice buildup. A licensed Greener Solutions technician will help clean the hard-to-access coils and remove any buildup to ensure optimal performance.
- Refrigerant leak refills: Our technicians are trained in how to handle these volatile and dangerous chemicals and how to identify areas with possible leaks. We can make system repairs to prevent further discharge and ensure that the AC system is properly charged.
- Duct / fan repairs: Airflow problems generally stem from either a ducting issue or a problem with the intake fan, both of which we will examine to ensure optimal performance and airflow.
- Drain / repair clogged lines: Condensate lines that are clogged will need to be cleared to allow the discharge of humidity collection.
- Replace AC filter: Blocked airflow due to a dirty air filter is likely the easiest low hanging fruit solution to frozen coils. This will be the first thing that is examined to determine if the AC unit is running optimally.
Preventative Maintenance to Keep Coils Working Great
All of the problems related to frozen AC coils are easily preventable with the proper maintenance and upkeep. This type of maintenance plan generally includes quarterly to biannual inspections and ongoing servicing. GS Home Services can catch the early signs of AC coils freezing so the problem never gets out of control. Regular servicing removes debris and keeps supporting systems working efficiently to minimize AC coils freezing over.
A coil that keeps icing over rarely fixes itself, and running the system that way can lead to bigger repairs down the line. If your AC is freezing up, let Greener Solutions Heating & AC take a look before the next Central Valley heat wave arrives.