Why Your Window air conditioner not blowing cold air?

Is your window air conditioner not blowing cold air? Don’t worry! We’re here to help!

In this helpful guide, we’ll explain why your window air conditioner is not blowing cold air and provide you solutions based on my experience to fix it.

So, let’s jump right in and solve this puzzling issue together!

Why Does Your Window Air Conditioner Not Blow Cold Air? 9 Most Common Causes

Here are the 9 most common causes why your Window AC Unit Fails to Produce Cold Air.

1. Insufficient Refrigerant Levels:

To be honest, I have repaired many window ac units with the same issues and one most common cause I found in most of them is low refrigerant level.

Refrigerant has a big hand in the cooling process as it circulates within the AC system and absorbs heat from the indoor air and expels it outside.

However, when a unit suffers from low refrigerant levels, the ability of the unit to remove heat from the indoor air becomes low to no. As a result, your window AC unit fails to blow cold air. 

The reduced amount of refrigerant can occur due to several reasons, but the two most common are leaks in the system and improper initial charging. Leakage can happen over time due to factors like corrosion, wear and tear, or poor installation. 

If there is a leak, the refrigerant gradually escapes which leads to a decline in cooling performance. Additionally, improper charging during installation can result in an insufficient amount of refrigerant in the system from the beginning.

To address the leak, it is recommended to have a technician. Take note that refrigerant handling requires specialized training and equipment, so it will be best to rely on professional expertise rather than attempting to address this issue yourself.

2. Dirty Air Filters

A dirty air filter can literally be a hardcore enemy of your air conditioner unit. It causes several issues, from increased noise levels to decreased cooling efficiency, and can even lead to freezing up of your window AC.

dirty air filter of window air conditioner

The consequences of a dirty filter are numerous and undesirable. When dust and debris accumulate on the air filter, they obstruct the airflow, which prevents your AC from blowing cold air effectively.

While a dirty filter may not completely block the cold air, it certainly reduces the amount of cool air coming out. However, if the filter becomes completely blocked, it can definitely restrict your window AC from blowing out cold air.

So to avoid the filter from getting nasty, regular cleaning is necessary. It’s recommended to clean it every 30 days. However, if you use your AC extensively throughout the day, cleaning it every 15-20 days is a good practice.

Cleaning the filter is just easy AF. Just take a bristle brush and give it a thorough scrub or gently wash it with mild soap and water. That’s all it takes to keep your air filter clean.

3. Faulty Thermostat

A faulty thermostat can be a potential cause for a window air conditioner not blowing cold air. The thermostat acts as the mastermind of your AC system. It holds the power to regulate the temperature and tell the unit when to start or stop cooling, depending on what the user wants.

When the thermostat doesn’t work properly, it disrupts the smooth communication between the user’s temperature preferences and the operation of the air conditioner. As a result, the AC may not cool the room enough or it may stop blowing cold air altogether.

To fix a faulty thermostat, double check and adjust the settings correctly. Make sure the thermostat is set to the desired temperature and cooling mode. If the problem continues, you may need to replace the thermostat with a new one.

And watch this video to learn more:

4. Electrical Issues

Electrical issues can be an obvious reason why your window air conditioner isn’t blowing cold air. The proper functioning of an AC unit relies on a reliable and uninterrupted supply of electricity.

When there are electrical problems, they can interfere with the AC system’s ability to cool effectively. A tripped circuit breaker is one potential electrical problem. It is a safety device that automatically cuts off power when an electrical circuit is overloaded or faulty.

melting of Electrical Wires in window ac can cause fishy smell

Another issue could be loose or damaged electrical connections. To address electrical issues, check the circuit breaker panel and ensure that the breaker is in the “On” position.

If it has tripped, resetting it may resolve the problem. Next make sure that all wiring connections associated with the air conditioner are secure and tight.

By fixing electrical problems, the window air conditioner can receive a steady and dependable power supply. This allows it to work correctly and blow cold air as it is supposed to.

5. Failed Compressor

In case the compressor of your air conditioner is not working, it can be a reason why your window AC fails to blow chilly air. The compressor is a crucial component of the AC system responsible for compressing the refrigerant and facilitating heat transfer.

It has a big contribution in the cooling process. When the compressor of your unit fails, it disrupts the entire cooling cycle, resulting in low cooling or no cool air at all.

There are various reasons why a compressor may fail, including worn-out bearings, faulty valves, broken seals, and lack of lubrication.

Lubricating the compressor is a simple task that only takes a few minutes. You can remove the back cover and add some compressor oil to the motor housing to ensure proper lubrication.

However, fixing more serious issues like worn-out bearings, faulty valves, and broken seals requires the expertise of a professional.

6. Frozen Evaporator Coil

window air conditioner frozen evaporator coils

A frozen evaporator coil can be a common cause for a window air conditioner not blowing cold air. When the coil gets frozen, it hampers the cooling process and restricts the airflow, resulting in low to no cooling.

The freezing of the evaporator coil can occur due to restricted airflow, often caused by dirty air filters and blocked vents. To troubleshoot a frozen evaporator coil, first, turn off the air conditioner and allow the coil to thaw completely.

Once the coil is thawed, clean it if it is dirty. Additionally, clean the air filters and ensure that the vents are not blocked to maintain proper airflow and prevent the coil from freezing again.

7. Blocked Air Vents

Air vents work to distribute the cooled air throughout the room. But what will happen if these vents get blocked? Well, as you guessed it, the unit won’t be able to blow out cool air.

But, why do my air vents become blocked?

It is a good question! Here is the answer: Air vents get blocked due to the accumulation of dust, debris, or other particles. Over time, these particles can build up and create a barrier, obstructing the flow of air.

To resolve this issue, check the vents and remove any dust, dirt, or debris that are present. You can gently vacuum or use a soft brush to clean the vents.

8. Fan Motor Problems

Fan motor problems can be a common reason for a window air conditioner not blowing cold air. The motor’s job is to drive the fan blades and circulate the air within the Air conditioning unit.

When the fan motor encounters issues, it can impact the cool air blowing out of your window ac. Most of the fan related issues can be solved just by lubricating it.

The fan motor relies on proper lubrication to ensure smooth operation. If it lacks lubrication, it can cause friction and strain on the moving parts which result in motor failure.

9. Poor Insulation

Poor insulation can cause a window air conditioner to not blow cold air efficiently. Poor insulation in walls, ceilings, or floors can allow heat from the outside to seep into the room or cool air to escape, reducing the cooling efficiency.

Gaps or cracks around windows and doors can also contribute to poor insulation. Adding insulation and sealing gaps and cracks can improve insulation and prevent air leakage, resulting in improved cooling performance.

Read Next: Silent Window Aircon of 2023

What are preventive tips to avoid a window air conditioner from not blowing cold air?

To ensure your window air conditioner constantly blows cold air, it’s crucial to prioritize regular maintenance. Regular maintenance is just like a one man army. It will not only prevent your  window air conditioner from not blowing cold air, it will help prevent your window ac to smell like fish.

Here are the some regular maintenance tasks that can help prevent a lack of cold air:

  • Checking and Cleaning the Air Filter
  • Clearing Blocked Vents
  • Cleaning the Evaporator Coil
  • Lubricating the Compressor and Fan Motor
  • Cleaning the Condenser
  • Cleaning the fan

When should you call a Professional Technician?

Knowing when to call a professional technician for assistance with your window air conditioner is crucial to ensure safe and effective repairs. While many maintenance tasks can be performed by homeowners, more serious situations need the expertise of a qualified technician.

Here are some instances when it is advisable to contact a professional:

  1. Refrigerant Issues: If you suspect a refrigerant leak or your AC unit is consistently low on refrigerant, it is essential to seek professional help. 
  2. Complex Mechanical Issues: In cases where you encounter complex mechanical issues with your AC unit, such as a malfunctioning compressor, motor, or fan, it is advisable to call a professional technician. These components are intricate and require specialized knowledge to repair or replace effectively. 
  3. Warranty Coverage: If your window air conditioner is still under warranty, it is recommended to contact the manufacturer or an authorized service center to handle any repairs. Attempting to repair the unit yourself or seeking assistance from unauthorized technicians may void the warranty.

Window AC Unit Not Blowing Cold Air: FAQs

1. Why is my window air conditioner blowing warm air? 

Ans: If your window air conditioner is blowing warm air, it could be due to reasons such as incorrect thermostat settings, issues with condenser coils, low refrigerant levels or the fan motor problems.

2. Is it necessary to hire a professional for window air conditioner repairs?

Ans: While some minor issues can be resolved by following troubleshooting steps. However, it’s advisable to hire a professional technician for window air conditioner repairs. They have the knowledge to accurately diagnose and fix complex problems.

3. What if none of the troubleshooting steps resolve the issue?

Ans: If you’ve attempted all the troubleshooting steps and the problem persists, it’s best to contact a professional HVAC technician.

4. Why is my air conditioner running normally but not blowing cold air?

Ans: If your window air conditioner is running normally but not blowing cold air, it may be because of low refrigerant levels or a faulty compressor. These factors can hinder the cooling process and result in not blowing cold air from your unit even when it is running normally.

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David Jack

David Jack

David Jack is a veteran when it comes to air conditioners, he love helping people find solutions to their problems with AC units. His specialty is helping people find the right Air-Conditioner for their needs, whether that means replacing a broken unit or adding on to an existing system. He is also great at diagnosing problems and fixing them quickly. He learned this from my father Jack Smith who was an air conditioner repairer, he has 2 years of experience in this field.

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