On a hot sunny afternoon when you want to relax in the cool environment of your home, you realize that your air conditioner won’t work. Why? Because it has frozen. What a bummer. Your only option now is to open the windows at home and pray like crazy that a cool breeze is blowing outside. Nine times out of ten, you won’t be that lucky. The next step would be to call your HVAC company and ask them to send somebody ASAP. The good news is that a frozen AC is not the end of the world. The bad news is that it will still take some time to resolve the problem. You can defrost a frozen AC unit, so take a deep breath and relax. Gather your patience because a frozen AC will take a little long to defrost.
What Is A Frozen AC Unit?
Don’t be confused by the term “frozen AC unit”. It does not mean that your air conditioner will become encased in a block of ice. When the flow of air is insufficient, it makes the temperature of the coils drop below freezing. The moisture present in the air then gathers on top of these coils and increases the ice buildup on your air conditioner. This is what is known as a frozen AC.
What To Do When The AC Freezes
1. Turn The Thermostat OFF – Ice formation on the air conditioner is an indication of the refrigerant being extremely cold. You need to stop the flow of this excessively cold refrigerant as it can kill your compressor. Why is that so? It is so because the AC compressor can only handle the refrigerant in the form of superheated gas. Normally, the thermostat is on the “COOL” setting. You need to turn it “OFF”. Turning it “OFF” will stop your AC from repeatedly sending cold refrigerant to the outdoor unit.
2. Switch The Fan To ON Position – Do not make the mistake of turning the AC fan setting to AUTO. This is because in “AUTO” setting the blower motor runs only during a cooling cycle. Since you have turned the thermostat from COOLING to OFF, your air conditioner will not go through any cooling cycles. The fan setting should be ON so that it pulls warm air from inside the home and forces it to blow non-stop over the frozen coils of the AC. This helps the ice thaw faster.
This two-step process will ensure that your frozen AC thaws or defrosts quickly and adequately. However, if you want to speed up the process a little more by lending a helping hand, you can use a hairdryer on low heat to blow additional warm air. Once the AC is completely free of ice, clean up the water puddles around the unit.
Frozen AC – How Long Does It Take To Defrost?
Depending on the extent of ice buildup on your AC, it can take anywhere between an hour to a day to defrost completely. While you are waiting for your AC to defrost, you need to pay attention to these two things –
1. Drain Pan Overflowing – As the ice melts it may overflow in the drain pan and leak onto the floor causing puddles. Spreading towels on the floor around the AC unit will help keep your floor dry.
2. Clogged Condensate Drain – When the ice on the evaporator coil thaws, it turns into water. This water drips into a condensate drain pan. From here the water flows outside through a condensate drain line. At times, the water picks up dirt along the way and clogs the drain line. A clogged drain pipe can cause the water to back up and overflow. You need to be on the lookout for such an occurrence and unclog the condensate drain to keep dripping water to a minimum.
What Causes The AC to Freeze?
The main reason behind a frozen AC is dirty air filters. In fact, there could be a number of other reasons as well, but this is the only one which you can deal with on your own. If changing the air filter does not solve the problem, you need to call the experts to take care of it.
When the air filter is dirty, it smothers the air conditioner. As a result, the warm air cannot flow freely over the evaporator coil. In turn, the refrigerant becomes colder than usual, and so the coils also turn excessively cold. When the moisture present in the air comes in contact with the too cold coils, it transforms into ice. Therefore, you need to make sure that the air filters are clean and free of dirt.
If you have changed the air filter and yet there is no respite, it means that the root of the problem is somewhere else. The most probable reasons could be a faulty blower motor, refrigerant leak, a stuck expansion valve, collapsed duct or something else altogether. These problems need expert handling, and so your best option is to contact your local HVAC company.
Now that you have read this post, you are well aware of how to safely defrost a frozen AC unit. When the AC is frozen, remember how long it will take to defrost will depend on the ice that has built up on the coils. You cannot rush the matter. All you can do is to ensure that the root of the problem is tackled. Ignoring your AC problems will not make them go away. In fact, that will just compound the issue. The best course of action is to address each issue as soon as it arises. There are many things that you can do yourself and yet there are many which are out of your scope. You need to be able to identify what you can do and what you can’t. If things seem overwhelming, you can always contact your local HVAC technician.