Why Did My Aircon Suddenly Shut Off and Won’t Turn On?
- Last modified on December 9, 2022
- By econcoolsg

Table of Contents
It’s a scorching day, but your air conditioner isn’t working! You want your air conditioner to perform flawlessly every time you switch it on; after all, it is your comfort companion throughout the year.
However, your Aircon unit may occasionally abandon you and fail to switch on. Don’t worry if you’re in a similar circumstance! It might be readily rectified as a do-it-yourself project or, in certain situations, with a call to a professional.
Is the aircon Not Turning On? Here’s Why
There might be a variety of causes, ranging from maintenance concerns to your unit becoming old; we have developed a comprehensive list to assist you in determining why your AC is not turning on and how to solve the problem.
This blog will go through the most common reasons why your air conditioner won’t switch on. In many circumstances, you can handle the problem without contacting a professional. However, remember that if you can remedy the problem, but it reoccurs, you should always call a professional for servicing and repair.
There can be a variety of causes, ranging from maintenance and servicing issues to your unit becoming old; we have compiled a comprehensive list to assist you in determining why your aircon is not turning on and how to troubleshoot the problem.
14 Common Reasons Why Your Aircon Unit Is Malfunctioning
1. A tripped circuit breaker
Circuit breakers are meant to shut down when they detect an overload of power. This is a positive development. It keeps your house safe from flames.
Breakers may trip due to utilising many appliances at once or because an appliance is old and consumes power.
Whatever the reason, the aircon will not turn on if the circuit powers your air conditioner trips. Check to determine whether a breaker needs to be reset.
2. Thermostat Problems
Your thermostat is the means through which you communicate with your air conditioner. So, if the thermostat isn’t operating correctly, your air conditioner will know it has to be turned on. Check the screen on your thermostat first. If your thermostat is turned off or has a blank screen, try turning it back on.
If the thermostat does not turn on, it may be due to dead batteries. Replace the thermostat’s batteries as soon as possible.
If your thermostat still doesn’t turn on, it might be a hint that you need to replace it. A professional technician will need to come in and look at it.
3. Condenser Unit Unplugged
Check the cord that comes out of your air conditioner. The issue might be as easy as the air conditioner not being plugged in, particularly if you have a window unit. In most situations, a small brown line running from your aircon will be linked to a panel on the side of your house.
These cables have the potential to become disconnected or chewed through. This will cut off the energy flow to your air conditioner, preventing it from turning on.
4. Obstructed Air Filter
How frequently do you replace your air filters? Most individuals understand that this must be done regularly, but it is rarely prioritised.
Let’s go over some aircon fundamentals: Airflow is ensured by clean air filters. Air becomes impeded when they become caked with particles and dust.
Under normal conditions, an air conditioner would collect moisture from your home. Water droplets would then gather in a condensation tray before draining outdoors through drain lines. When your air filters become clogged, the water droplets freeze and coat the coils with layers of ice.
5. Clogged Evaporator Coils
Dander, grime, dust, and other yucky detritus from our daily lives can accumulate on the evaporator coils, condenser, or air conditioner’s filter. Essentially, your air conditioner contains components that are subject to junk buildup. When dirt accumulates on different elements of your air conditioner, it reduces efficiency and can eventually lead to a total malfunction—schedule frequent aircon maintenance for yourself and your system.
6. Fuse Blown
The fuse box is outside of your house, near the condenser unit. We recommend you switch off the air conditioner and power supply, as with every other item on this list. We cannot emphasise this enough. Failure to do so risks electrocution.
After you’ve found the fuse box and switched off the power, remove the fuses and use a multimeter to check for continuity. If one of the fuses fails, you may replace it at a hardware shop or through internet sellers. Just be sure you photograph it, so you have the model and brand ready.
7. The Aircon Drain Line is Clogged
Lack of maintenance will ultimately make the AC overwhelmed with moisture and clogged with junk. Maintain your condensate drain line clean by pouring a cup of hot water down it once a month. Before you begin, switch off the air conditioner and the power supply.
8. There’s a Refrigerant Leak
Coolant is refrigerant. However, unlike an automobile, it can be added sparingly. When an air conditioner is operating correctly, there is no need to add refrigerant. However, your air conditioner will not function properly if you have a coolant leak. It may also result in refrigerant toxicity.
The lack of refrigerant is not due to your air conditioner depleting the fluid. In this case, leakage is most likely to blame. Cracks in the aircon coil may form over time, resulting in leakage. Furthermore, failing to schedule regular maintenance might result in rusting in the long term.
An aircon specialist like Econcool can only resolve this problem, so instead of attempting to fix it yourself, call us, and we will be there.
9. The Aircon Capacitor Has Failed.
If your aircon unit is having difficulties starting up, or if it is beginning and stopping suddenly, or if you hear snapping noises from the outside aircon unit, your aircon’s capacitor has likely failed.
The capacitor is an essential component of your aircon system. It is linked to the motor’s circuit and gives it a starting push. The capacitor disconnects from the circuit when the motor reaches a certain speed.
10. The Motor Broke Down
If your aircon produced strange noises before it failed to work ultimately, the problem might be a damaged motor. A capacitor test may be used to determine whether your motor still has life in it.
If the problem is with your motor, you should obtain many quotes on how much it would cost to repair it vs. how much it would cost to replace the aircon unit.
11. Defective power cord or outlet
The power cable might fray and wear out if your item has been kept for a season. Power failures can also cause cord damage.
Perhaps it’s not the wire, but the fact that the outlet was plugged in. You may test the outlet’s functionality by connecting to other appliances. If none of these work, contact an electrician to repair or replace the outlet, depending on the extent of the damage.
Pro tip: Never try to fix the wire or power outlet yourself. You risk receiving an electric shock if you do not cut off the power source. There needs to be more than just turning off the switch isn’t; you must also turn off the electricity from the main power box.
12. Incorrect Temperature Readings
It’s also conceivable that your thermostat is misreading the temperature in your home and turning off automatically.
This can occur if your thermostat is positioned on an outside wall or near an area with significant temperature variations, such as a utility room or kitchen.
To resolve this issue, you will need to place the thermostat in a new position.
13. Your house has a wiring problem
How many difficulties do you experience with electric appliances in your house overall? Do your lights frequently flicker on and off? When you initially plug in your appliances, do you hear a buzzing sound? Often, there are indications of electrical issues.
If you frequently suffer any of these symptoms, you’ll need an electrician to address the underlying reason. If it has harmed your air conditioner, you’ll need an HVAC specialist to perform a diagnostic test.
14. Unclean Aircon Unit
If your air conditioner isn’t working, the problem might be as easy as dirt! It may refuse to turn on if your evaporator coils or condenser lines are unclean. If you are not confident about cleaning it yourself, fear not. Econcool is here to help you with aircon servicing.
Econcool has more than 20 years of experience with a team of experts in aircon servicing in Singapore.
Emergency Aircon Repair Services in Singapore
While most current aircon systems may last up to 20 years, even the best-kept systems will require maintenance from time to time. That is why having a trustworthy air conditioning provider is critical for homes.
If your air conditioner doesn’t turn on, the skilled technicians at Econcool can immediately assist you. We provide emergency air conditioning repair services because we realise that living in Singapore without air conditioning would be terrible. Contact us now to learn more, or book an appointment online now!