Window Air Conditioner Not Cooling? Here's How to Fix It

A window air conditioner helps keep your home cool in hot weather. But if it’s running but not cooling, don’t panic. There are simple things you can check and fix before calling out the repair team or deciding to buy a new one.

1. Check the Thermostat Settings

Start with the basics. Make sure your window AC is set to “Cool” mode and the temperature is between 22 and 26°C. Also, check that the fan speed is set correctly. If everything seems right but it still doesn’t cool, try the next steps.

2. Clean or Replace the Air Filter

Over time, dust and dirt can build up in the air filter, blocking airflow and making the AC less effective. Dirty or clogged filters are a common reason why a window unit doesn’t blow cold air.

Solution:

Take out the filter and wash it with water and a little soap if it can be reused. If not, throw it away. It’s best to clean the filter every month if you use the AC often. This helps prevent problems and keeps your unit working well.

3. Inspect the Condenser Coils

The coils on the outdoor unit of the AC help push heat out of your room. If they’re dirty, the AC can’t get rid of the heat, so it doesn’t cool as well.

Solution:

Turn off the power, then gently clean the coils with a vacuum or brush. Be careful not to bend the fins. If you’re not sure how to do it, it’s best to call a professional.

4. Check for Ice Build-Up

If you see ice building up in your AC unit, it might be due to blocked airflow or low refrigerant.

Solution:

Turn off the unit and let it completely thaw. Clean the air filter and check that the vents aren't blocked. If the problem keeps happening, you might need to call a professional to check the refrigerant levels and get it sorted before it leads to bigger issues.

5. Always check the AC unit’s capacity

Always check the AC unit’s capacity. Your AC unit’s capacity needs to match the size of the room to work properly. If it’s not powerful enough, it will run all the time and still won’t cool the room well. If it’s too powerful, it may cool the room too quickly without removing humidity, leaving the air feeling damp or uncomfortable.

Solution:

Measure your room size, count doors and windows, consider heat from nearby sources, and how much sun the room gets. Then pick an AC with the right BTU rating for these factors.

Try Taqeef’s online AC Calculator for accurate guidance on selecting the right unit for your space.

6. Eliminate Power Supply Issues

If the compressor won’t start or the fan runs but doesn’t cool, it might be a loose connection, power problem or a faulty electrical component. This can seriously damage your AC if you don’t fix it.

Solution:

Make sure your AC is plugged directly into a good power outlet. Avoid using extension cords if you can, and use a surge protector to protect your unit.

7. Check the Fan and Compressor Function

If you’ve checked the coils, filters, and power but it still won’t cool, pay attention. If the fan runs but the compressor doesn’t, there may be a mechanical problem.

Solution:

A technician may need to check the compressor, capacitor, or refrigerant level.

Time to Upgrade?

If your window air conditioner is outdated or continues to underperform despite troubleshooting, it may be time to consider a replacement. Investing in a quality brand ensures lasting comfort and offers greater energy efficiency and long-term savings.

At Taqeef, we offer a reliable range of window air conditioners designed for the extreme heat of the UAE. Our  energy-saving units from trusted brands like Midea and O General also come with a free 5 year warranty, delivering dependable and sustainable cooling for pure peace of mind.