My AC isn’t blowing cold air. What do I do?

On a hot summer afternoon, with the sun burning anything in sight, the worst thing to happen is your AC air not blowing cold air. The sweat forms on your forehead, and you begin to Google questions like “my AC is broken” and “why is my AC blowing hot air?”. That’s probably how you got here.

Well, you’re in luck! Today, we will be talking about some of the reasons why your AC isn't blowing cold air, as well as some possible fixes.

A lot of reasons could be behind an AC unit not blowing cold air, and while some are possible to check by yourself, it is advisable to call in an HVAC repair professional to take a more comprehensive look at the whole system in order to determine the true reason and give it the required repair it needs to work again.

Chances are, you don’t want to waste time in this situation. We get it. Here are some of the reasons why your AC might not be blowing cold air.

Power Issues

If your portable AC isn't blowing cold air, it could be that your unit cord isn't plugged into the wall. Try to make sure the cord is plugged in. If it is, check your circuit breaker. It may have tripped because of a power surge.

Fan and Fan Motor

Your AC’s fan draws in air, which goes over cold evaporator coils. This air is then circulated back into your home. If the fan becomes slow, or the fan motor develops a fault, there will be insufficient air for the evaporator coils, allowing a buildup of ice. Try to check the condition of the fan to see if it is the cause of cold air not blowing into your home, and call a repair person to fix it if it has a fault. Check that the interior fan (usually in your attic), as well as your exterior fan (usually on the side of the outside of your house), are both working.

Dirty Compressor

Check the outside unit. If it’s dirty, clean around it. If a compressor is blocked due to debris, leaves, dirt, or other materials, it could allow the system to stop functioning properly, ultimately letting air that isn't cold inside your home.

Thermostat Issues

Sometimes, the issue is the thermostat. The temperature might have been tampered with (those pesky kids).

Other times, it’s a calibration problem. Reset this by taking it to both extreme levels to see whether it works. When you can confirm that your AC has begun to work, you can then set the thermostat to your desired temperature and enjoy the cold air again

Also, check the wiring that connects to the thermostat. There could be some wiring damage that is preventing the thermostat from getting power.

Clogged Filter

When a filter traps dirt and other particles and debris, over time, it tends to become clogged. This clogged filter reduces the airflow into the system, and the AC sometimes shuts down on its own thanks to the built-in shut down mechanism installed in most ACs today. If your unit is older, it may have overworked itself and broken a component. Go to Filter King’s online store to find your size and get new filters. They should be replaced every three months.

Ice Build-up

A dirty evaporator coil and filter can cause low airflow, and could result in an ice build up. Check your outside unit to see if any pipes or tubes are frozen. If they are, an ice blockage could be the problem. To rectify this issue, simply clean the coil and the filter, then restart the system. If the ice isn't melting off, put on the fan, and allow it to blow enough hot air to melt the ice.

Note: Make sure your system is off while you clean your coil and filter. You certainly don’t want to electrocute yourself, and a running system with no filter might cause more problems in the future.

Clogged Drain

An AC draws moisture from the room and takes it outside through a pipe. Sometimes, this pipe can become clogged with algae or mold, or even with rust, causing water to move back up into the system, triggering a system shut down. When this happens, the best thing is to unclog the drain. An expert will know the best way to unclog one, but you could try to unclog it yourself if you can see the blockage.

Low Refrigerant Levels

A unit's refrigerant level could become low if there is a leak in the refrigerant infrastructure. To have your refrigerant level topped up, we recommend calling a professional. Not only do they know how to use refrigerant safely (it can be VERY toxic in certain circumstances), but they’ll also be able to find the leak and patch it up for you.

Airflow Safety Switch

In most AC units today, there is an integrated safety switch pre-installed into the system. If anything trips this mechanism, it can shut down your system until you manually reflip it. Look up your system online to find where the switch is.

Air Conditioner Size

The size of your air conditioner can also be an element in your AC troubles. If an AC is too small in comparison to the room size, it will become overworked and ultimately, its capacity to blow cold air will become diminished, just as an AC unit that's too big would consume more energy, and increase your monthly energy bill.

Note: It is advisable to replace an AC unit system which is over 10 years old or has consistent repair issues.

In trying to check why your AC isn’t blowing cold air, we recommend hiring a professional to examine the system. This is overall the easiest and safest way to do it.

However, there are a few things you could try to check for personally. These include:

1. Checking the thermostat

2. Cleaning your clogged air filter

3. Cleaning your dirty condenser

4. Checking your circuit breaker box.

While we’re on the topic, you should probably replace your air filters. Most people completely forget to do this, and you’re supposed to do it every three months. Check out our online store to find your size and the strength of the filter you want. With fast delivery and the ability to start a subscription, it’s no surprise that Filter King is one of the most popular air filter delivery services on the planet.