Is your window air conditioner not blowing cold air but running? This problem is more common than you might think. In this guide, we'll explore the reasons behind it and provide practical steps to get your window AC blowing cool air again.

Let's start by looking at the most common reasons list why your window AC not cooling but the fan is running:

• Dirty Air Filter

• Blocked or Damaged Condenser

• Fan and Motor Issues

• Thermostat Problems

• Temperature Sensor Issues

• Electrical and Wiring Issues

• Ice Buildup

• Faulty Capacitor

• Dirty Evaporator Coils

• Compressor Problems

• Clogged Drain and Condensate Issues

• System Aging

Dirty Air Filter

A dirty air filter occurs due to a lack of regular cleaning, environmental dust, or high usage frequency. This issue restricts airflow, leading to frozen evaporator coils and abnormal compressor pressure, which prevents the Window AC from blowing cold air.

To solve this problem:

1. Carefully remove the air filter, usually located behind the front grille.

2. Clean the filter with running water or mild detergent.

3. Dry the filter completely, reinstall the filter and close the panel.

4. Replace the filter if it is damaged or too worn.

5. Follow the manufacturer’s instructions to install the new filter properly.

6. Keep the area around the AC unit clean and dust-free by vacuuming regularly.

Related reading: How to Clean a Window Air Conditioner: A Step-by-Step Guide

Blocked or Damaged Condenser

If the condenser coils are clogged with dirt and debris or the unit itself is obstructed or damaged, it will prevent proper heat dissipation of the window AC, leading to reduced cooling efficiency and potential system overheating.

To solve this problem:

1. Inspect the condenser unit for any visible obstructions, such as leaves, dirt, or debris.

2. Use a soft brush or vacuum to clean loose dirt and debris from the coils.

3. Gently hose down the coils with water or coil cleaner for more thorough cleaning. Be careful not to bend the fins.

4. Use a fin comb or soft brush to carefully straighten the bent or damaged fins.

Fan and Motor Issues

Blocked, bent, or broken fan blades, along with fan motor problems, can prevent proper air circulation, leading to reduced cooling efficiency and potential system malfunction in a window air conditioner.

To solve this problem:

1. Strangten or replace the bent or broken fan blades.

2. Clean the fan blades using a soft cloth and mild detergent to remove dirt, debris, and any visible obstructions.

3. Lubricate the fan motor to ensure smooth operation.

4. Examine the fan motor for any signs of malfunction, such as unusual noises or irregular operation.

5. Replace the fan motor if it is faulty.

Thermostat Problems

Thermostat problems occur when the thermostat is malfunctioning or incorrectly calibrated, which can lead to inaccurate temperature regulation and poor cooling performance of the window air conditioner.

To solve this problem:

1. Check the thermostat settings to ensure it is set to the desired temperature and cooling mode.

2. Replace the thermostat batteries to rule out power issues.

3. If the thermostat is not accurately reflecting room temperature, calibrate the thermostat or replace the thermostat.

Temperature Sensor Issues

Temperature sensor issues arise when the sensor is malfunctioning, leading to inaccurate temperature readings and improper cooling or heating of window air conditioner.

To solve this problem:

1. Locate the temperature sensor near the evaporator coils or air filter.

2. Ensure the sensor is not out of place and is positioned correctly in the airflow path.

3. Clean the sensor gently with a soft cloth to remove any dust or debris that may affect its accuracy.

4. Replace the sensor if it is faulty or damaged, following the manufacturer’s instructions, or ask for help from HVAC manufacturers.

Electrical and Wiring Issues

Electrical and wiring issues can occur due to tripped breakers, blown fuses, or faulty wiring, leading to the window AC unit not operating correctly or at all.

To solve this problem:

1. Check the circuit breaker for the AC unit and reset it if it has tripped.

2. Inspect the fuse box and replace any blown fuses with ones of the correct rating.

3. Examine the wiring in the thermostat and AC unit for any visible damage or loose connections.

4. Consult a professional electrician if there are signs of electrical damage or if the issue persists after basic troubleshooting.

Ice Buildup

Ice buildup in a window AC unit is usually caused by low refrigerant levels, restricted airflow, or dirty evaporator coils, which prevent proper heat exchange and lead to the freezing of the coils. It can block airflow, reduce the AC unit's cooling efficiency.

To solve this problem:

1. Turn off the AC unit and allow the ice to melt completely.

2. Check the refrigerant levels using a professional gauge. If refrigerant levels are low, properly recharge the refrigerant to the correct levels.

3. Examine the evaporator coils for dirt and clean them gently if needed.

4. Ensure proper airflow around the unit by clearing any obstructions and making sure the vents are open.

5. Schedule professional maintenance if the problem persists, as there may be a leak or other issues requiring expert attention.

Faulty Capacitor

A faulty capacitor in a Window AC unit is usually caused by age, power surges, overheating, manufacturing defects, or using the wrong voltage rating. It can prevent the fan motor from operating properly, resulting in poor airflow and reduced cooling efficiency.

To solve this problem:

1. Locate the capacitor, usually found near the fan motor or compressor.

2. Inspect the capacitor for visible signs of damage, such as bulging or leaking.

3. Use a multimeter to test the capacitor's functionality by following the manufacturer's instructions.

4. Replace the capacitor that is compatible with your window AC.

Dirty Evaporator Coils

Caused by the accumulation of dust, dirt, and other airborne particles, the evaporator will become dirty over time. It can reduce cooling efficiency and cause ice buildup, which obstructs airflow and diminishes the window AC unit's performance.

To solve this problem:

1. Gently clean the coils using a soft brush or a vacuum to remove loose dirt and debris.

2. Use a coil cleaner for more thorough cleaning by following the product instructions.

3. Allow the coils to dry completely before reassembling the unit and restoring power.

Compressor Problems

Common causes include electrical issues, overheating, refrigerant leaks, lack of maintenance, and age-related wear and tear. Compressor problems can significantly impact the overall performance and cooling capacity of the window AC unit, leading to inadequate cooling or complete system failure.

To solve this problem:

1. Listen for unusual noises from the compressor, such as clicking, buzzing, or humming, which can indicate a problem.

2. Check the compressor for overheating, which may be felt as excessive warmth on the unit's exterior.

3. Inspect electrical connections and wiring to ensure they are secure and undamaged.

4. Test the compressor with a multimeter to check for electrical continuity and functionality.

5. Consult a professional technician if the compressor is not functioning properly, as it may need repair or replacement.

Clogged Drain and Condensate Issues

Clogged drain and condensate issues are typically caused by the buildup of dirt, algae, or debris in the drain line, which obstructs the flow of water. It can cause water to back up in the window AC unit, leading to backups and potential system shutdowns.

To solve this problem:

1. Locate the drain line and condensate pan, typically found near the bottom of the unit.

2. Inspect the drain line for any blockages or buildup of dirt, algae, or debris.

3. Clear the drain line using a wet/dry vacuum, a thin brush or a mixture of water and vinegar to remove any obstructions.

4. Check the condensate pan for standing water and clean it out to prevent mold growth.

5. Ensure the condensate airflow switch is functioning properly; if it is stuck or faulty, it may need to be reset or replaced.

System Aging

As an AC system ages, its components can wear out, leading to decreased efficiency and comfort. Even after reconditioning, your window air conditioner may not achieve optimal cooling results. Evaluate your air conditioner and consider replacing it with a higher efficiency and quieter model if:

1. The unit is over 10 years old: Older air conditioners often lack the efficiency and performance of newer models.

2. Frequent breakdowns: If your window AC frequently malfunctions, it may be more cost-effective to replace it.

3. Excessive noise: Older units can become noisier over time, disrupting your comfort. Consider an ultra quiet AC unit for a more peaceful environment.

4. High repair costs: If repair bills are approaching the cost of a new unit, upgrading can provide better efficiency and lower maintenance expenses.

The Window AC Still Doesn't Cool? Call Experts for Help!

If your window AC isn't cooling properly, common issues like dirty filters, clogged drains, or compressor problems might be the cause. When simple fixes aren't enough, it's best to consult professionals. Dellahome offers expert assistance to resolve these issues efficiently, using quality components from HVAC manufacturers.

FAQ

Should I turn off the window AC if it's not cooling?

Yes, you should turn off the window AC if it's not cooling to prevent potential damage to the system. This could be due to issues like a dirty filter, frozen coils, or low refrigerant levels. It's best to inspect the unit and call a professional for a thorough check-up.

What is the best setting for a window air conditioner in summer?

The ideal setting for a window air conditioner in summer is around 24-26°C (75-78°F). This temperature range provides a comfortable environment while being energy-efficient. Additionally, using the "Auto" or "Energy Saver" mode can help maintain a consistent temperature and reduce energy consumption.

How to know if refrigerant is low?

Low refrigerant levels in your AC can be indicated by several signs, including reduced cooling efficiency, warm air coming from the unit instead of cool, ice buildup on the evaporator coils, and a hissing or bubbling noise from the unit. If you notice these symptoms, it's essential to have a professional check and refill the refrigerant.

Why is my window air conditioner not reaching the set temperature?

If your window air conditioner is not reaching the set temperature, it could be due to a dirty filter blocking airflow, blocked vents, low refrigerant levels, or an improperly sized unit for the room. Additionally, a malfunctioning thermostat or electrical issues could also be the cause. It's advisable to clean the filters, check for blockages, and consult a professional if the problem persists.