The air conditioner compressor is the heart of your cooling system. Located in the outdoor unit, the compressor processes the refrigerant, enabling it to absorb heat and release cool air into your space.
When the compressor overheats or malfunctions, your aircon may struggle to cool your home effectively. Given Singapore's sweltering weather, ensuring your compressor is in top condition is crucial. This is why any problem with the AC compressor should be dealt with immediately.
How Do You Tell If the AC Compressor Is Not Turning On?
Sometimes, you might not immediately realize that your AC compressor is not turning on because other parts of the air conditioner, like the fan or indoor unit, may still be running. Additionally, if the AC compressor is weak or failing, the cooling loss may happen gradually rather than suddenly. This makes it less noticeable until the room no longer reaches the desired temperature.
As a homeowner, it’s best if you know the signs of the compressor not turning on early to prevent bigger AC problems in the future. Here are some signs to watch for!
- Warm air is blowing from the vents instead of cool air.
- The outdoor unit is running, but there’s no humming sound from the compressor.
- You notice circuit breaker trips frequently when you turn on the aircon.
- Unusual noises or clicking sounds occur when trying to start the aircon.
If you experience any of these, it’s likely that your AC compressor is not turning on, and further inspection is needed.
Important! In Singapore’s tropical climate, aircon compressors typically last 10 to 15 years with proper maintenance. However, frequent use and lack of servicing can reduce its lifespan.
8 Causes of an AC Compressor That Won't Turn On
Issues with Power Supply or Faulty Relay
First, check if you have any issues with the power supply. One of the most common reasons for compressor failure is an air conditioning system that is not getting enough power to work. There may be a fault in the wiring, or a busted fuse that needs repair. You may also have a faulty relay switch that is cutting off power to your unit.
Either way, check if your AC is plugged in and if other appliances in the house are working. If you have any electrical issues, contact a professional and licensed electrician instead of tackling the electrical problem yourself. The issue may be with the air conditioning unit as well, and one of our Luce Aircon HVAC technicians will be able to diagnose the problem.
Troubleshooting Guide
- Check your circuit breaker first. If it has tripped, reset it and see if the compressor starts.
- Look for loose or damaged wiring around the aircon unit.
- If you experience frequent power trips, contact a licensed electrician in Singapore to inspect your wiring.
Faulty Thermostat
The thermostat controls the aircon’s temperature settings. If it’s malfunctioning, it may not send the correct signal to turn on the compressor. In Singapore, many people use smart thermostats and remote-controlled ACs, but even these can fail due to battery issues or sensor problems.
Troubleshooting Guide
- Check if the thermostat is set to cooling mode and at the right temperature.
- If it’s a battery-operated thermostat, replace the batteries and see if that helps.
- Try lowering the temperature setting and listen if the compressor kicks in.
- If the thermostat is unresponsive, it may need professional repair or replacement.
Old Age
In Singapore where aircon runs daily, compressors experience more wear and tear. If your unit is over 10-15 years old, the compressor may simply be worn out.
Troubleshooting Guide
- Get a professional assessment to determine whether to repair or replace the compressor.
- If your aircon is more than 10 years old and constantly needs repairs, it may be time for a new aircon unit.
- Consider upgrading to an energy-efficient inverter aircon to save on electricity bills.
Blown Fuse
Check if other appliances plugged into the same circuit breaker line are also malfunctioning. If this is the case, you may have issues with a fuse that has overloaded and blown. This happens when the AC unit is overworked, such as on a hot summer day, or when the room is too big for the size of the unit.
A blown fuse can also be an indication of an underlying problem, such as an overheating air conditioner or an overloaded circuit breaker.
Troubleshooting Guide
- Check your circuit breaker first–if it has tripped, reset it and see if the compressor starts.
- Look for loose or damaged wiring around the aircon unit.
- If you experience frequent power trips, contact a licensed electrician in Singapore to inspect your wiring.
Incorrect Installation
If your aircon wasn’t installed properly, it could lead to wiring issues, poor airflow, or drainage problems that affect the AC compressor’s ability to function. Some homeowners in Singapore still opt for cheap installation services without researching the quality of the service. It’s important to know that improper installation can lead to long-term issues.
Troubleshooting Guide
- Check if the outdoor unit is level. If it’s tilted, it can cause drainage issues.
- Hire a reliable aircon technician in Singapore to inspect and reinstall if needed.
Refrigerant Fluid Leaks
When refrigerant leaks out of the AC unit, there is nothing for the compressor to process. As a result, the compressor won't turn on as it detects a problem with your unit. Refrigerant levels do not diminish over time, so if your AC unit needs to top up on coolant, you know you have a leak somewhere within your unit.
Refrigerant leaks are one of the common causes of AC compressor problems in Singapore. There is no DIY approach to refrigerant leaks, as the coolant can be harmful to your health when handled improperly.
Troubleshooting Guide
- Check for hissing sounds from the aircon unit–this could indicate a refrigerant leak.
- If the aircon still blows warm air even after a filter cleaning, a gas top-up may be needed.
- Contact Luce Aircon to diagnose the problem, fix the leak, and top up your coolant.
Valve Issues
When air conditioner valves are defective, they can overwork the compressor until it overheats, causing the compressor to break down over time. Your condenser coil may also leak or is simply faulty. AC compressor valve issues can be identified by an air conditioner that is not blowing cold air, strange noises from your unit, and an overheating compressor.
Troubleshooting Guide
- Contact a professional aircon technician in Singapore to inspect and fix the valve issue.
Faulty Compressor
Sometimes, the issue is with a malfunctioning HVAC compressor itself, instead of an external problem. The AC compressor may have worn down over time, causing damage to the part. You can detect a faulty compressor if that is the only part of your air conditioner that won't work.
A faulty compressor may also come with other symptoms, such as a broken blower motor, malfunctioning evaporator coil, or leaking condenser coils that contribute to overworking the compressor.
Troubleshooting Guide
- Listen for any clicking or humming sounds from the compressor–if it’s silent, it may be faulty.
- Check if the compressor is overheating by feeling the outdoor unit. If it’s extremely hot, the compressor might shut down due to overheating.
- If your air conditioner is over 10 years old and frequently needs repair, replacing the compressor may be a better option than repairing it.
How to Prevent a Faulty AC Compressor?
Tip #1 Check Your Wires
Always check your wires and plugs before using an appliance. Do not use your air conditioner if you notice frayed or burnt wires. If your electrical sockets spark as your unit is plugged in, turn the air conditioner off immediately and unplug the unit whenever safely possible.
Tip #2 Avoid Overloading Circuit Breaker
Avoid plugging too many extension cords, appliances, and plugs into the same socket as it may blow the circuit breakers. As much as possible, plug large appliances in completely separate power sockets to avoid overloading the circuit.
Tip #3 Routine Maintenance
Routine maintenance by one of our aircon experts in Singapore is the best way to diagnose and fix an issue with your air conditioning unit before it becomes a problem for you. Have your entire unit checked out during routine cleaning to find any weak points or fix any leaks.
Tip #4 Valve Replacement
A Luce Aircon HVAC technician will be able to check for broken or weak valves and replace them as needed. Fortunately, valves can be easily fixed or replaced and is a relatively simple fix compared to replacing other parts of an air conditioner.
Tip #5 Compressor Replacement
If your compressor is broken, chances are you'll need a replacement. Our technicians are experts in compressor replacement for all of our clients in Singapore, we will make sure you can keep using your HVAC unit without any further problems or issues!
Cool Your Home
Aircon issues can be a pain to experience, but fixing is made convenient and hassle-free with Luce Aircon's general services! We are Singapore's air conditioning expert, which will deliver exceptional cleaning and repair services to keep your aircon feeling like brand new!
Contact us today for a full list of our air conditioning services.
