The last thing you want when the temperature is rising outside is a broken air conditioner. This article will help you answer the question, “Why Is My Window AC Not Cooling?”?

Why My Window AC Isn't Cooling

There are a number of reasons why your window AC unit isn't pumping out cold air as it should. Our tips range from the simplest do-it-yourself fixes to the more complicated issues you may have to deal with. Additionally, we cover AC problems that could indicate a replacement is needed.

Your Window AC Is In the Wrong Mode

There could be one simple reason why your window air conditioner isn't cooling. It might not be in Cool mode. Window air conditioners are designed to have multiple modes, and each mode serves a particular purpose. There are some variations in what modes your AC has because it is not all built the same way. The three modes on almost all window air conditioners are Cool Mode, Fan Mode, and Dry Mode.

Here is a quick explanation of what each mode does. Be aware of the options - and get the most from your window air conditioner!

Cool Mode

During Cool Mode, your AC unit will remove heat from the room until the set temperature of your AC thermostat is reached. In addition to dehumidifying the air, it will work to maintain the room temperature once you have set it to the desired temperature. Once it reaches the desired room temperature, it will work to maintain that temperature until you change the thermostat or its mode.

If your window AC is not cooling, Check whether your window AC is in Cool Mode. If not, try switching it to Cool Mode and see how it changes your space. You will probably need to keep hunting for the source of the trouble if it is still having difficulty cooling your space even when it is in Cool Mode.

Fan Mode A window AC that is set to Fan Mode is essentially acting like a simple household fan. In Fan Mode, it does not blow cold air, but instead circulates the air in the room to create good circulation. On a fresh spring day, when the outside air is ideal, and you simply want to circulate that air throughout your home, this mode is ideal.

Dry Mode It is also known as Dehumidifier Mode, and, as you might have guessed, it works by drying out the air, so most newer window air conditioners come with this mode. In Dry Mode, your window AC unit only removes moisture from the air, not cooling it. You should use this mode on a humid day when everything feels damp, and your main goal is to dry things out, not necessarily cool the house.

Your Window AC Filter is Dirty or Clogged

Also, the back fins might be dirty.

In order for your AC to cool at its normal capacity, your air conditioner filter must be cleaned periodically. If your air conditioner filter is dirty or clogged, it will likely restrict the air flow. Moreover, if the filter is very dirty, it may cause frost to form on the evaporator coils, which may further hamper airflow. If you're experiencing this problem, it's best to replace the filter and remove any obstructions. Warm, soapy water is the best way to clean evaporator coils that have accumulated dirt.

Your Window AC is the Undersized for your Room

A window air conditioner's efficiency, or how much cool, dry air it can produce, is not the same for every model. It is possible that your window AC isn't cooling because it isn't the right size.

Your Window AC Has a Broken Thermistor

An air conditioner in a window has a device called a thermistor. The thermistor monitors the temperature of the area to be cooled, and then sends signals to the compressor that turn the cold air on or off as needed. In case the thermistor detects a temperature that is too high, it will tell the compressor to shut off the cool air.

Your Window AC Has a Broken Compressor

One of the most important parts of an air conditioner is the compressor. It acts as a pump to circulate refrigerant that collects heat inside your home and dumps it outside. Cold air flows through this compressor, and air conditioners cannot function properly without a properly functioning compressor. When your air conditioner blows warm air, even in Cool Mode, and you don't notice any other issues with the unit, your compressor may have failed. Window air conditioners should be replaced if their compressors break.