Window AC Not Blowing Cold Air? 5 Reasons

Is your Window AC not blowing cold air, and you can’t tell why or fix it? No need to get frustrated; in this guide, we will provide you with answers to your Window AC not blowing cold air. By expelling the hot air from the room and sending it outside, an air conditioner cools the area by replacing the air inside with cooler air. So, why is your Window AC not blowing cold air?

Incorrect mode selection is one of the most frequent causes of a window air conditioner not blowing cold air. However, if the thermostat is set to “Cool” and the appliance still doesn’t blow cool air, there could be several issues, including low refrigerant, clogged air filters, and coil freeze-over. 

5 Reasons Why Your Window AC Not Cooling

1. Your Window AC Filter Is Dirty Or Clogged

It is recommended that you clean the air conditioner filter occasionally. Your air movement is likely restricted, and your AC is not cooling as effectively as it should be if your filter is dirty or blocked. 

Further impeding good air movement is the possibility of frost forming on the evaporator coils if the filter is extremely dirty. The filter should be changed, and any debris clogging the filter area should be removed. This is the best solution. You can wash the evaporator coils with warm, soapy water if you see any dirt accumulation.

If your window air conditioner is not chilling adequately, check the filter and the back fins/coil, as this is one of the most typical AC issues!

2. Your Window AC Is In the Wrong Mode

One straightforward reason your Window AC not cooling might not be set to Cool. Window air conditioners have many settings, and each mode has a specific purpose. There is some diversity in the modes that your Window AC may have because not every window AC is constructed the same way. However, these three modes—Cool Mode, Fan Mode, and Dry Mode—are in practically all Window air conditioners.

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The functions of each mode are briefly described here. Get the most out of your window air conditioner investment by being aware of your modes!

Fan Mode

When your window air conditioner is in the fan mode, it operates like a regular household fan. When in fan mode, the appliance circulates the room’s air to improve airflow rather than blowing any cold air into the room. This mode is wonderful for a crisp spring day when the temperature outside is ideal and you need a little extra air movement inside.

Cool Mode 

When your air conditioner is in the Cool Mode, it will remove heat from the space until the thermostat setting is reached. Additionally, it will reduce humidity, making the air more comfortable and less “muggy.” When the temperature in the room reaches your preferred level, it will work to keep it there until you change the thermostat’s setting or switch the unit’s mode.

Dry Mode

This setting is present in most recent window air conditioners. Dehumidifier Mode is another term for it, and as you might have guessed, it works to dry out the air. When in Dry Mode, your window air conditioner works to remove moisture from the air; it does not cool the air. This setting is perfect on a cool, humid day when everything seems damp.

Since you are familiar with each mode and what it accomplishes, make sure you are in Cool Mode before moving on. This easy solution might be the solution.

3. Your Window AC Has A Broken Compressor

One of the most crucial components of an air conditioner is the compressor. It circulates refrigerant that absorbs heat inside your house and releases it outside, much like a pump. This causes the cold air to flow, and the air conditioner cannot operate properly without a functioning compressor.

If your AC is blowing warm air, even in Cool Mode, when the filter and fins are clean and there are no other obvious problems with the appliance, this may be a sign that your compressor has failed. It’s probably time to think about getting a new window air conditioner if your compressor is broken.

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Does it make sense to swap out the compressor? Most likely not. Typically, an older air conditioner will have a compressor failure. Since the compressor is an expensive component that must be replaced, purchasing a new window air conditioner would probably be more cost-effective.

4. Your Window AC Is The Undersized For Your Room

There are differences between window air conditioners in terms of how much cool, dry air they can produce or how much heat they can expel every hour. Your window air conditioner might not be cooling because it is too tiny for the room.

British Thermal Units, or BTUs, quantify the cooling capacity of window air conditioners. Most window air conditioners require 20 BTU to cool a square foot of space. For instance, a 10,000 BTU window air conditioner is required to cool a 500-square-foot room with an average ceiling height.

Check the BTU rating of your window air conditioner before assuming it is broken to see how much cooling power it has! The air conditioner you use may be too little to cool your home adequately. If so, you have two options: upgrade your window air conditioner by buying one with a more excellent BTU rating to replace your current one, or buy a second unit to complement your current one.

In either case, it is a good idea to double-check that your window air conditioner has enough BTUs to chill the area you need it to. This will prevent your window AC from using electricity and driving up your cost without really chilling your house

5. Your Window AC Has A Broken Thermistor

A thermistor is a component in Window AC. It watches the temperature of the space to be cooled and sends commands to the compressor to switch on or off the cold air in response to the temperature of the space (like your living room, for example). The compressor will be instructed to stop pumping cool air if the thermistor detects that the area has attained the target temperature.

A properly working thermistor will also tell the compressor to keep blasting cold air if the region is too warm. A damaged thermistor is one potential reason your window air conditioner isn’t cooling. You must take off the unit’s exterior cover to reveal the electrical control board to find the thermistor for your Window AC. Once you have discovered the control board, the thermistor is a little component with a glass bulb. Check your thermistor for wear and tear and carefully look for any damage or disconnection.

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Replace your thermistor if it shows any indications of deterioration. You can do this yourself, but be sure to use a new, manufacturer-approved thermistor instead of your old one! Don’t worry if you feel more at ease leaving the dissection of the air conditioner to the experts; they’ll know exactly how to find and fix your damaged thermistor. Your home will soon once more be filled with cool air!

Proper Maintenance For Your Window AC Not Blowing Cold Air

Your window AC needs regular maintenance, just like any other equipment. A specialist must inspect all operating parts, and filters must be replaced.

Having an HVAC maintenance tune-up twice a year is the typical suggestion. Fall and spring are the ideal times for this. Before it becomes hot or cold, the technician may inspect your HVAC system and make any required adjustments or repairs. This maintains your appliance operating effectively and lowers the possibility of future unplanned failures and pricey issues.

When To Replace Your Current Window AC 

Unfortunately, repairing window air conditioners is more expensive than buying a new one. The majority of repair businesses charge a lot to identify the issue. The price of the parts comes next. You can often buy a new window air conditioner with a bill of $100 to $225.

When people ask us when to replace their current window air conditioner, we typically reply, “The older it is, the less you should put into repairs.” It makes sense to spend $100 or $150 to repair a room air conditioner under 5 years old. We don’t think spending that on an 8-year-old AC makes sense.

The range depends on your financial situation and circumstances. For instance, repairing the unit rather than replacing it is a cost-effective choice if you currently reside in an apartment but intend to move into a home—likely one with central air conditioning—in a year or two.

How To Know If Window AC Needs Freon

The AC runs without chilling the home.

  • Your vents don’t blow cold air.
  • Your energy costs increase.
  • The refrigerant lines are covered with ice.
  • Bubbling or hissing noises when the Window AC is off.

Conclusion On Window AC Not Blowing Cold Air

Your Window AC not blowing cold air can result from a wrong mode setting or a dirty filter. You can fix the dirty filter by washing it, but if it is related to any power issues, it is advisable to seek the service of an experienced technician.