Aircon Troubleshooting: Quick Fixes You Can Try at Home
- SURESH K
- Oct 15
- 4 min read
For many homeowners in Singapore, the air conditioner is more than just an appliance—it’s a necessity. With the hot and humid climate all year round, a sudden breakdown or poor performance of your AC unit can cause serious discomfort. Before you panic and call in professional help, it’s worth knowing that some common aircon issues can actually be solved with quick and simple fixes at home.
In this blog, we’ll explore the most frequent aircon problems, their possible causes, and the quick DIY solutions you can try before booking a technician. By understanding these troubleshooting steps, you can save time, reduce unnecessary service costs, and keep your unit running smoothly.
1. Aircon Not Cooling Properly
Problem: You turn on your aircon, but instead of the refreshing cool air you expect, the room still feels warm.
Possible Causes:
Dirty air filters restricting airflow
Blocked condenser or evaporator coils
Incorrect thermostat settings
Low refrigerant levels (gas leak issue – needs professional handling)
Quick Fixes:
Check the thermostat – Make sure it’s set to “Cool” mode and the temperature is set lower than the current room temperature.
Clean or replace filters – Clogged filters reduce cooling efficiency. Most filters can be washed with water and mild soap. Dry them fully before reinstalling.
Clear obstructions – Ensure no furniture or curtains are blocking the airflow from the indoor unit.
Inspect outdoor unit – Clear away leaves, dust, or debris around the condenser unit. Good ventilation is essential for cooling efficiency.
👉 If these steps don’t work, it might be a refrigerant issue. That’s when you’ll need professional servicing.
2. Aircon Leaking Water
Problem: You notice water dripping from your indoor unit, or worse, pooling on the floor.
Possible Causes:
Clogged drainage pipe
Frozen evaporator coil
Dirty air filters causing poor airflow
Low refrigerant level
Quick Fixes:
Turn off the unit immediately to prevent water damage.
Check and clean the drainage pipe – Use a vacuum or plumbing snake to clear any clogs.
Clean the air filters – Poor airflow can cause ice build-up that melts into water.
Restart the unit after cleaning and monitor.
👉 If water leakage persists, call a technician to check the refrigerant levels and deeper system issues.
3. Strange Noises from Aircon
Problem: Instead of the usual low hum, your aircon makes rattling, buzzing, or grinding sounds.
Possible Causes:
Loose screws or panels
Debris stuck in the fan
Worn-out motor or fan belt
Faulty compressor (needs professional attention)
Quick Fixes:
Check for loose parts – Tighten screws and panels.
Clean the unit – Remove any leaves or dirt stuck in the outdoor fan.
Lubricate fan motor (if accessible) – This can reduce squeaking sounds.
👉 Persistent grinding or buzzing noises indicate a motor or compressor issue—time to call a pro.
4. Aircon Emitting Bad Smells
Problem: Instead of clean cool air, the unit releases musty, foul, or burning smells.
Possible Causes:
Mold or bacteria growth inside unit
Clogged or dirty filters
Electrical wiring issue
Stagnant water in drainage system
Quick Fixes:
Clean or replace filters regularly to eliminate trapped dust and bacteria.
Check for mold – Open the panel and inspect for mold around coils or filters. Clean with mild disinfectant.
Ensure proper drainage – Clean the pipe to avoid stagnant water buildup.
For burning smell – Turn off the unit immediately. This may indicate an electrical fault that needs urgent professional repair.
5. Aircon Turns On and Off Repeatedly (Short Cycling)
Problem: The AC keeps shutting down after running for just a few minutes.
Possible Causes:
Dirty air filters
Incorrect thermostat placement (e.g., near a heat source)
Electrical or compressor issues
Quick Fixes:
Clean filters to improve airflow.
Check thermostat location – Ensure it’s not near sunlight, lamps, or appliances that emit heat.
Reset the system by turning it off for 10–15 minutes and restarting.
👉 If short cycling continues, it may be a compressor issue that requires professional servicing.
6. Aircon Remote Not Working
Problem: You press the remote, but nothing happens.
Possible Causes:
Dead batteries
Remote sensor blocked
Faulty remote or receiver
Quick Fixes:
Replace batteries – The simplest fix!
Clean the sensor on both the remote and the unit.
Check distance and angle – Use the remote within a clear line of sight.
👉 If the remote is faulty, universal aircon remotes are available as replacements.
7. Aircon Blowing Warm Air
Problem: The aircon runs, but instead of cooling, it blows warm air.
Possible Causes:
Thermostat incorrectly set
Dirty condenser coils
Refrigerant leak
Quick Fixes:
Check thermostat settings – Ensure “Cool” mode is selected.
Clean condenser unit – Dirt buildup on outdoor coils reduces cooling.
Reset circuit breaker – A tripped breaker can disrupt cooling.
👉 If refrigerant is the cause, you’ll need a licensed technician to refill and check for leaks.
Preventive Maintenance Tips
While troubleshooting helps in emergencies, prevention is always better. Here’s how you can keep your aircon in top shape:
Clean filters monthly – Especially in Singapore’s humid climate.
Schedule professional servicing every 6 months – To deep clean coils, fans, and drainage.
Keep outdoor unit clear – Avoid blocking airflow with plants or objects.
Check for unusual signs early – Address small issues before they turn into costly repairs.
Use your aircon smartly – Avoid setting extremely low temperatures (like 16°C). Instead, 24–25°C is more energy-efficient and prevents strain on the system.
When to Call a Professional
While these DIY fixes are handy, some problems require expert attention. Contact a professional aircon service provider if:
Water leakage continues after cleaning
The unit stops cooling completely
There’s a burning smell or electrical sparks
Gas top-up is required
You suspect serious mechanical or compressor damage
Professional servicing not only restores performance but also extends the life of your system.
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