Anyone living in Singapore knows how quickly a room heats up without cooling. When your aircon is running but not blowing cold air, comfort drops almost instantly. The humid weather makes this one of the most common issues for households and offices alike.
The good news is that a unit that stops cooling rarely means the system has completely failed. More often, it points to minor problems that can be fixed with proper care. From dirty filters to low refrigerant levels, there are a number of reasons why cooling performance dips.
In this guide, we break down the most common causes, what you can do at home, and when it is time to call in a licensed technician. If you would like a more detailed look at servicing options, check out our list of aircon servicing Singapore for trusted providers who can help.
Why Your Aircon Might Not Be Cold

Clogged air filters
When filters get clogged with dust, air cannot pass through as it should. The flow becomes weak, and the room never cools the way you expect. The unit keeps running and using more power, yet the space stays uncomfortable and heavy, leaving little relief from Singapore’s heat.
Low refrigerant levels
Air conditioners need refrigerant gas to draw heat out of the air. When the level drops because of leaks or gradual loss, cooling weakens. The system keeps running, but the air feels less refreshing. This is a common reason units in Singapore fail to deliver the cool comfort expected.
Dirty condenser coils
The outdoor unit pushes heat away from your home. When its coils get covered in dirt or debris, that process slows down. Warm air lingers, the system overheats, and cooling power drops. This build-up is a common issue in a humid climate where dust and humidity speed up coil grime.
Faulty thermostat
Sometimes the problem comes from inaccurate temperature readings. A faulty thermostat may shut the compressor off before the room is cooled. This leaves the space warmer than what was set on the control. Replacing or repairing the thermostat usually brings the system back to steady and reliable cooling again.
Blocked or leaking ducts
In central or multi-split systems, air has to travel through ducts. If there are leaks or blockages, cool air escapes before reaching the room, making the system seem underpowered.
Improper unit size
In central and multi-split systems, air moves through ducts before reaching the room. When leaks or blockages develop, much of the cool air escapes along the way. The unit then seems weak, even though it is running. Sealing and cleaning the ducts usually restores proper airflow and cooling.
Lack of routine maintenance
When maintenance is skipped, dust and minor wear slowly build up inside the system. Over time, this makes the unit less efficient and the cooling weaker even though it is still running. Regular checks and cleaning help keep it working at full strength.
Quick Fixes You Can Try at Home
There are a few safe steps you can try before calling a technician. Start by cleaning or replacing the air filters. This alone improves airflow and cooling noticeably.
Check the thermostat settings to make sure the temperature is not set higher than intended. Sometimes a simple reset can correct the problem.
Also, keep doors and windows closed so cool air does not escape. Lastly, ensure there is no clutter or obstruction around the outdoor unit, which should always have room to breathe.
These fixes are easy to do, but if cooling problems continue, the issue may be deeper and best left to professionals.
Want to buy a new unit instead? Check out our blog on Gain City or Prism
When to Call a Professional
If you notice loud noises, frequent leaks, or persistent weak cooling even after cleaning, it is time to seek expert help. Licensed technicians have the equipment to check refrigerant levels, repair electrical faults, and perform deep cleaning safely.
On Google, one customer shared how a technician clearly explained the problem, topped up the gas, and restored the cooling immediately. Another client mentioned that the team was punctual and had the room feeling comfortably cool again in minutes. These accounts show reliable and efficient service.
These accounts show exactly why servicing is so valuable. Trying to fix gas or electrical problems yourself can easily lead to damage or create a safety hazard, so it is always safer to rely on certified professionals.
Need help? Our full guide on aircon servicing Singapore gives a look at trusted providers that can keep your unit in top shape.
Preventing the Problem in the Future
The best way to keep your unit cooling well is through consistent servicing. For heavy daily use, cleaning and checks every three to four months are recommended. For lighter use, twice a year may be enough.
Using timers and energy-saving modes can also prevent overworking the unit. This allows it to run efficiently without constant strain.
Lastly, make sure you choose the right capacity unit for your room size. A properly sized system cools quickly and does not waste energy trying to do more than it can handle.
Conclusion
When your aircon is not cold, it can feel frustrating, but the causes are usually easy to identify. Dirty filters, low refrigerant, or clogged coils are some of the most common issues. Simple cleaning may fix the problem, but sometimes professional servicing is needed.
Customer reviews show how effective timely servicing can be. Many people report fast responses, polite technicians, and immediate improvements in cooling after a professional visit. As one review put it, “The service was efficient, and the unit is now running like new.”
With regular upkeep and the right support, you can avoid warm, uncomfortable rooms and keep your system working efficiently.
