How Long To Thaw AC Coils

Unfortunately, when it comes to repairs or fixes to your HVAC unit it’s usually not cheap. It also occurs at the worst time when you really need the AC to work. It is a great idea to know a little bit about your AC unit and the parts and pieces in the event that something breaks down or just stops working. Not all is lost if something does stop working. Certain parts of the AC unit can be fixed by the homeowner without much stress. Thawing the AC unit is something that most homeowners will go through at some point for various reasons. You are also likely to unclog your condensation line at some point as well. How long to thaw AC coils? Typically, it takes about 24 hours, however, you could speed that process up with a blow dryer and some awareness.

Let’s take a look below at some of the best preventative maintenance and the steps to thaw the AC coils.

How Can I Prevent This

The only way to really know if you have frost build-up or HVAC issues is by visibly seeing the frost and experiencing a lack of cold air blowing through your system. The best way to prevent this from occurring is by making sure airflow and refrigerant are where they need to be. Checking the airflow involves your air filter(s). Make sure there is no debris and dust build-up that can prevent your unit from processing airflow properly. Replace the air filter and vacuum up any loose debris in the housing of the filter. Also, check the evaporator coil to make sure that it also is free from debris and dust. Before dusting or vacuuming the evaporator coils, check with your local HVAC company. This Is to ensure they are properly cleaned and not damaged.

Next, check the refrigerant levels of your system. If the refrigerant levels are too low, the pressure in the refrigerant lines can send the external temperatures of the evaporator coils to below freezing. Then, this causes any condensation that has built up on the coils to begin frosting over. Thus, you will need to thaw the AC coils. Lastly, any faulty valves, loose fittings, or pinholes can cause leaks to the system and evaporator coils. This is how refrigerant levels typically get low so make sure you are getting your HVAC unit serviced and inspected regularly.

Frozen AC coils that need thawing.

What Should I Do To Thaw The AC Coils

The best way to unfreeze your evaporator coils is to:

  1. First, make sure that you turn the thermostat OFF. This gives the coils time to thaw. You might notice that it takes 24 hours for the coils to thaw.
  2. If you need the unit up and running more quickly, look to use a hair dryer. Be careful not to over heat the evaporator coils or the pipes running into the unit.
  3. You might be able to just switch the thermostat to FAN ONLY setting, if the unit just has frost built up. The air from the blower will defrost the evaporator coils.
  4. Call a professional air conditioning technician before turning the AC back on.
  5. Allow the AC unit to thaw while you await the air conditioning technician.
  6. Check your air filter to see how dirty it is. If you have a dirty air filter, replace it.

How Much Does It Cost

The first part of getting your AC unit coils unfrozen deals with the filter and your drain line. You will want to unclog the drain line first before getting to unfreezing your evaporator coils. The national average for unfreezing your evaporator coils is $600 to $850. This is typically labor and materials. Replacing the coils can become expensive and are often the best option. Replacing evaporator coils that are not under warranty can cost you up to $2,000. If you want to avoid paying so much, keep your HVAC unit maintained throughout the year.

Other Recommended Maintenance

While you are having your HVAC unit serviced, check your fresh air intake vents. During certain parts of the year, rodents or even birds might find the vents as a great place to nest. This would block up your actual intake and could a negative airflow. Definitely, an area of your home to keep an eye on.

Another thing to consider while your HVAC system is being maintained or repaired is how long does the ac unit actually lasts. Depending on where you live can either keep your unit lasting a long time or seriously degrade your unit due to environmental conditions. Understanding when the HVAC system was purchased and how often it is actually used and serviced is a must. You don’t want to be caught with some random expense that you never really planned for.

Lastly, it is always a great idea to clean other areas of your home at the same time you are having systems serviced. Getting everything on the same schedule is a sure way to remind yourself of what maintenance is needed every 6 months. When your HVAC system is being serviced or thawed out, you should consider also cleaning your stone fireplace. Depending on where you live, you might have a fireplace to clean. This is a big undertaking for some, so doing it at the same time as your other systems is a smart idea. You will save on stress and money as items are less likely to break down.

Frozen coils on an HVAC unit.

When Do I Call A Professional

When dealing with your HVAC unit it is advised that you call a professionally licensed HVAC contractor. You do not want to risk damaging more parts to the air conditioning unit. If you do not understand how to thaw your unit, you could seriously damage major portions of the air handler and external unit. Hire a professional to assist you in unfreezing any part of the HVAC unit. If you aren’t sure who to call, reach out to your local home inspection team for a referral to a reputable HVAC service company.


Having your HVAC system checked on a regular basis is the only real way to ensure that it is working effectively. Service and inspection on an HVAC unit should be conducted every 6 months to 1 year depending upon the environmental conditions in your area. Extreme heat and extreme cold could cause you to call on your local professionally licensed HVAC service team twice a year.

In order to save time and money, call on your local home inspection team to look at your HVAC unit as well as the other main systems of your home. Not only can the home inspection team provide you with a bonified report of potential repairs, but they can recommend the most reputable service teams in the business. You want to make sure that you are calling on a reputable HVAC service team and not someone that does a poor job or has a bad reputation in your area. Plus, there might be other projects that you need to complete at the same time. This could keep you organized with those projects moving forward. Reach out to Heartland Inspections in the great Minneapolis St. Paul and surrounding areas.