Window air conditioners are a popular choice in Singapore, especially in HDB flats or smaller rooms. They’re affordable, easy to install, and efficient for cooling moderately sized spaces. Additionally, a window air conditioner is also easier to clean and maintain, making it a practical option for many Singaporean households.
However, window ACs are not immune to malfunctions, and one common issue with window air conditioners is blowing warm air instead of cold air. This issue often indicates an underlying problem with your window AC unit. Find and fix the root cause of the problem to maintain the condition of your window AC.
Why Window Air Conditioner Is Not Blowing Cold Air (and How to Fix It)
Problem with Thermostat
If your window AC not blowing cold air, the first thing you should do is check the thermostat. The thermostat in a window AC unit is responsible for regulating the temperature of the room by turning the compressor on and off.
When the thermostat is working properly, it will turn on the compressor when the room temperature rises above the desired setting and turn it off when the room temperature reaches the desired setting. But if a problem occurs in the thermostat, it can cause your AC to misread the room temperature and be unable to blow cold air.
How to Fix It?
- Make sure the thermostat is set to “cool” mode.
- Adjust the temperature to a lower setting.
- If the AC still doesn’t cool, the thermostat may need replacement.
Restricted Air Flow
Since window air conditioners have their entire cooling system housed in one compact unit, restricted airflow can easily occur. This problem is especially common in Singapore, where high humidity and dust accumulation can clog air filters and vents faster than expected. Your window air conditioner may have blocked vents, debris buildup, or a dirty aircon interior, which will cause AC unable to blow cold air. Restricted airflow often occurs when the unit is improperly cleaned or is not cleaned regularly, allowing dust and dirt to clog the vents.
How to Fix It?
- Check and clean the air filter regularly (at least once a month in Singapore’s dusty environment).
- Remove any obstructions near the vents.
- Call a professional aircon technician for a thorough cleaning once every 3 months.
Faulty Fan Motor or Fan Blades
If your AC is making unusual rattling or clunking noises, it may be due to a faulty fan motor or broken fan blades. A faulty fan motor will cause restricted airflow, which will also cause a window air conditioner to blow warm air instead of cool air.
Alternatively, the issue may lie with bent or broken fan blades. The blades may have broken off, causing irregular air flow, or the blades might need to be topped up with lubricant to spin smoothly.
How to Fix It?
- If the fan blades are bent or broken, they need to be replaced.
- The motor may need lubrication or replacement if it’s worn out.
Get aircon servicing immediately if you hear loud noises coming from your unit!
Dirty Evaporator Coils
The evaporator coils absorb heat from the air to cool it down. Over time, these coils can become covered in dust and grime, reducing their efficiency. Many homeowners in Singapore experience this problem due to the humid climate, which causes dirt to stick to the coils faster. Some symptoms of dirty coils are, window AC not blowing cold air and water leakage from the unit.
How to Fix It?
- Regular maintenance and coil cleaning to prevent this issue.
- If the unit is leaking water and not cooling properly, professional servicing is recommended.
Issues with the Outdoor Side
Most AC types have an outdoor unit, also called a condenser unit, that releases the warmed air outside. A window AC unit would have a similar exhaust system connected to the indoor unit, and when this side gets clogged or malfunctions, then it can cause the warm air flow to circulate back indoors. Your window AC may have issues with the compressor, outside fins, or vents that are causing your unit to malfunction. Cleaning the condenser unit usually fixes the issue, but advanced problems may require the expertise of a licensed HVAC technician.
How to Fix It?
- Clear the outdoor vents from obstructions like walls, plants, or debris.
- Clean the condenser coils and fins regularly.
- If the compressor is faulty, contact an HVAC technician for repair or replacement.
Low Refrigerant Levels
A refrigerant (coolant) is necessary for cooling the air. If your air conditioner is running low on refrigerant, it won’t be able to cool effectively. Refrigerant leaks are a common issue in older aircon units in Singapore. Not only unable to cool a room, but hissing sounds from the unit could also indicate a refrigerant leak.
How to Fix It?
- Refrigerant leaks are very dangerous, thus if you suspect a leak—it must be repaired immediately. Afterward, a professional aircon technician will refill the refrigerant back.
Power Issue
In some of our client who lives in older HDB flats in Singapore, we often find a power issue that causes a window air conditioner unable to cool a space properly due to an electrical problem. These older buildings still have outdated wiring that can cause power issues with the aircon.
How to Fix It?
- Ensure the AC is plugged into a dedicated power outlet.
- Check for blown fuses or tripped circuit breakers.
Wrong System for Your Home
A common issue we see with our clients in Singapore is the installation of undersized air conditioning units, particularly in larger HDBs. This results in inefficient cooling and premature wear and tear on the system.
How to Fix It?
- Before purchasing always make sure you purchase the right size aircon for the intended room
- If you install the wrong aircon system, consider upgrading to a more powerful unit or switching to a split-system air conditioner.
When to Call the Professionals?
If the basic troubleshooting that we highlight above does not resolve the issue, it’s best to call a professional aircon technician. Our Luce Aircon technicians are well-versed in the common issues of multiple air conditioner brands and models across Singapore. We can assure you only the best in aircon services, as we provide quality cleaning, maintenance, inspection, and repairs for your air conditioning unit!
Book an appointment with us today, and we can schedule you for a time slot that works for you!
