Living in Singapore’s hot and humid climate, your air conditioner isn’t just a luxury—it’s a necessity. Whether you stay in a condo, HDB flat, landed house, or a BTO, a well-functioning aircon is key to staying cool and comfortable.
But like any appliance, aircons break down over time. Here are 15 common air conditioning problems in Singaporean homes and what you can do about them.
- 1. Aircon Not Cold
- 2. Water Leaking From Indoor Unit
- 3. Aircon Making Noise
- 4. Bad Odors or Foul Smell
- 5. Unit Turns On and Off Repeatedly (Short Cycling)
- 6. Unusual Power Consumption
- 7. Airflow Is Weak
- 8. Outdoor Unit Is Noisy
- 9. Remote Control Not Working
- 10. Thermostat Doesn’t Seem Accurate
- 11. Gas Leaking or Low Refrigerant
- 12. Frozen Indoor Coil
- 13. Fan Not Working
- 14. Aircon Won’t Turn On
- 15. Bad Chemical Smell
1. Aircon Not Cold
One of the most frequent complaints. Your aircon is running, but the room just won’t cool down.
Possible causes:
- Clogged filters
- Low refrigerant gas
- Dirty condenser coils
- Failing compressor
Fix:
Start with a basic servicing. If the problem persists, a technician should check gas levels and clean internal components.
Book service here – https://www.stringssg.com/sg/aircon-servicing-singapore/aircon-not-cooling

2. Water Leaking From Indoor Unit
Dripping water from your unit can damage walls, furniture, and floors.
Possible causes:
- Clogged or cracked drainage pipe
- Full or overflowing drainage tray
- Frozen evaporator coil
Fix:
Book an aircon servicing. The technician will clean or replace the drainage pipe and clear any blockages.
Book service here – https://www.stringssg.com/sg/aircon-servicing-singapore/aircon-leaking-water

3. Aircon Making Noise
Unusual rattling, buzzing, or clicking sounds are red flags.
Possible causes:
- Loose fan blade or panel
- Motor issues
- Debris inside the unit
Fix:
Turn off the unit and schedule a check-up. Avoid using it further to prevent bigger damage.
4. Bad Odors or Foul Smell
A musty or sour smell can quickly ruin the comfort of your home.
Possible causes:
- Mould buildup
- Bacteria in the filter or coil
- Poor drainage
Fix:
Go for a chemical cleaning service to eliminate deep-seated mould and bacteria.
Book service here – https://www.stringssg.com/sg/aircon-servicing-singapore/aircon-chemical-wash-and-overhaul
5. Unit Turns On and Off Repeatedly (Short Cycling)
This affects both cooling and electricity bills.
Possible causes:
- Thermostat issues
- Dirty condenser coils
- Refrigerant problems
Fix:
Have a professional diagnose it—this could lead to long-term compressor damage if ignored.
6. Unusual Power Consumption
If your bill suddenly spikes, your aircon might be the culprit.
Possible causes:
- Low gas level (makes compressor work harder)
- Dirty filters
- Aged unit efficiency loss
Fix:
Regular servicing and cleaning help maintain energy efficiency.
7. Airflow Is Weak
The air is cold, but the room takes too long to cool.
Possible causes:
- Clogged filters
- Blocked fan
- Dirty blower wheel
Fix:
Clean filters monthly and schedule routine servicing to clean internal components.
8. Outdoor Unit Is Noisy
This usually indicates an issue with the compressor or fan motor.

Possible causes:
- Failing motor bearings
- Loose parts or panels
- Debris like leaves stuck inside
Fix:
Get a technician to inspect and clean the outdoor unit.
Book service here – https://www.stringssg.com/sg/aircon-servicing-singapore/top-3-reasons-for-noisy-aircon-compressor-how-to-fix
9. Remote Control Not Working
Sometimes it’s not the aircon—it’s the remote.
Possible causes:
- Dead batteries
- Faulty IR sensor
- Signal interference
Fix:
Change batteries first. If it still doesn’t work, try using a universal remote or consult your technician.
10. Thermostat Doesn’t Seem Accurate
Room feels warmer or colder than the setting.
Possible causes:
- Faulty sensor
- Poor thermostat placement (e.g., too close to a window)
Fix:
Relocate the thermostat if necessary or replace it if it’s malfunctioning.
Thermostat complete guide – https://www.stringssg.com/sg/aircon-servicing-singapore/aircon-thermostat
11. Gas Leaking or Low Refrigerant
You may notice reduced cooling and hissing sounds.
Possible causes:
- Worn-out connections
- Corroded coil
- Physical damage
Fix:
Do not DIY. A certified technician will safely top up or refill the gas and repair leaks.
Complete guide – https://www.stringssg.com/sg/aircon-servicing-singapore/aircon-gas-leakage
12. Frozen Indoor Coil
If you see ice on the evaporator coil, something’s wrong.
Possible causes:
- Dirty filters
- Refrigerant leak
- Poor airflow
Fix:
Turn off the unit and let the coil thaw. Then call a technician for a full inspection.
13. Fan Not Working
No air coming out of the unit even though it’s on?

Possible causes:
- Motor failure
- Electrical issue
- Broken fan blade
Fix:
A fan replacement or internal part repair is usually required.
Blower replacement guide – https://www.stringssg.com/sg/aircon-servicing-singapore/aircon-blower
14. Aircon Won’t Turn On
Nothing happens when you press the power button.
Possible causes:
- Power trip or blown fuse
- Faulty capacitor
- Remote sensor issue
Fix:
Check your circuit breaker first. If that’s not the issue, call a technician.
15. Bad Chemical Smell
A chemical or burning smell is serious and could mean a safety issue.
Possible causes:
- Electrical wiring damage
- Overheating components
- Gas leak
Fix:
Turn off the unit immediately and book an emergency service.
FAQs
What causes high energy consumption in air conditioning systems and how to reduce it?
High energy consumption is typically caused by inefficient operation due to duct leaks, clogged filters, low refrigerant, dirty coils, or aging components. Regular maintenance, cleaning, and timely repairs can improve efficiency and reduce electricity bills.
Why does my aircon emit bad odors and how can I eliminate them?
Bad odors from an aircon are usually caused by excess moisture, mold, or bacterial growth inside the unit, often due to high humidity in Singapore. Regular cleaning or replacing air filters, and professional servicing can help maintain air quality and eliminate foul smells.
What should I do if my air conditioner is producing loud or unusual noises?
Unusual noises from an air conditioner, such as clicking, buzzing, grinding, or rattling sounds, may indicate issues with the blower, refrigerant leak, faulty compressor, or fan motor. It is important to have a professional inspection to accurately diagnose and address the specific problem.
How can I prevent water leakage from my aircon unit?
Water leakage from an aircon unit often occurs due to condensation and blocked or damaged drainage pipes. Dirt, dust, and fungi can clog the drainage system, leading to leaks. Routine cleaning and maintenance by a technician to clear or replace the drainage pipe can prevent this issue.
What are the common causes of poor cooling efficiency in air conditioning units in Singapore?
Poor cooling efficiency in air conditioning units in Singapore is commonly caused by dirty air filters, low refrigerant levels, clogged coils, malfunctioning compressors, and gas leaks. Regular maintenance by professionals can help identify and fix these issues to ensure optimal performance.
In the hot weather of Singapore, an a well-functioning and efficient air conditioner is more of a necessity than a luxury. The aircon problems discussed above are the most common issues reported by users. However, it should be noted, that none of these issues are too much expensive if recognized and treated at the right time. Regular maintenance and timely repairs are essential for ensuring your aircon operates efficiently and reliably at all times. If any of these issues are faced, seek professional assistance for the benefit of your aircon and your household who will help you with the best solution. |
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