Aircon Capacitor: How to troubleshoot & cost of repair?

Introduction to Aircon capacitor?

Like what our founding father Mr Lee Kuan Yew said about Air-conditioner. It is the secret to our country’s success. Hence, it is almost impossible to live without an Air-conditioner in Singapore. Not to mention, work efficiently without an Air-conditioner. And if you have an Air-conditioner that is installed more than 10 years ago. Chances are, you might have encountered an Aircon capacitor failure before. Before we dive right into Aircon repair for you. Let us talk about different ways we can troubleshoot an Aircon. We will also let you know the approximate price for Aircon capacitor replacement.

  1.  What is an Aircon capacitor
  2. Aircon capacitor in inverter vs non-inverter Aircon
  3. How to know if your Aircon capacitor has malfunctioned?
  4. Steps to Repair an Aircon capacitor
  5. Faq for Aircon Capacitor
  6. Price for Aircon capacitor replacement

What is an Aircon capacitor?

 An aircon capacitor stores electric charge. It is a little similar to a battery. Just that it stores energy in a different way. It can’t store as much energy as a battery although it can charge and release energy much faster. This is very useful that is why you will find capacitor inside every Aircon circuit board.  There are two types of Aircon compressor capacitor. A compressor capacitor is the one that controls the compressor. Where as a fan capacitor is the one controls the Aircon fan motor.

aircon capacitor

How does a capacitor work?

In a printed circuit board, the capacitor stores energy . It can release the energy and smooth out interruptions to the supply. Which means, if a capacitor fails. The relevant parts that it controls will not be able to function.

 What is the Function of an Air-con capacitor?

 It typically works to start the motor of an Ac unit. A capacitor sends a jolt to start up the motor, similar to that of starting up your vehicle. In an AC unit, it works with these 3 types of motors : The compressor motor, the blower motor and the outside fan.

A capacitor also Process Signals and provide power to the Ac unit

Aircon capacitor in inverter Aircon vs Non-inverter

 Air con capacitor in non-inverter Aircon

 In a non inverter Aircon condensing unit, the capacitor is usually located just below the cover. It should only be replaced by trained technicians using proper handling and equipments. Because there is an electric charge to it, even if the Ac is turned off. You might experience an electric shock if it is not being handled properly.


 Aircon capacitor in inverter Aircon

In an inverter Air-conditioner, a capacitor is typically soldered into the printed circuit board. The amount of time needed to replace it would be very long. And the workmanship of the replacement is not guaranteed. Subjecting it to a lot of issues after the replacement. Hence, an Aircon technician normally replace the entire printed circuit board instead.


How do you know if your Aircon capacitor has malfunctioned?

Inverter Aircon unit 

For an inverter unit, we have to inspect the Aircon printed circuit board for burn marks. Nevertheless, standard operating procedure for Aircon PCB repair is to replace instead. Hence the technicians can just rely on the error code to know that the PCB has to be replaced. Technically, you can also replace the capacitor inside the PCB. But surprisingly, it could even be more expensive than replacing the PCB itself. Because, if the PCB is faulty and we suspect the capacitor is at fault. We will have to remove the capacitor from the PCB first. Nonetheless, the PCB is already soldered into the printed circuit board. It will be time consuming just to remove the capacitor without damaging it. 


Non inverter Aircon unit

For a Non inverter ac unit, it is much easier to detect. There are a few ways to do this.

Replace the capacitor directly

The easiest way is to replace the Aircon capacitor directly. If this causes the AC to start functioning again. Then the problem is most definitely caused by the capacitor. However do note that for a multi split Aircon unit. There are usually 2 capacitors inside the condenser unit. One of the capacitor will be responsible for each compressor. And there are 2 compressor inside a multi split AC. Nevertheless, if your Aircon compressor is running, but your Aircon fan isn’t. Then chances are, it is the fan capacitor that has to be replaced. Therefore, you have to identify the type of Aircon capacitor to be replaced first.

Measure the voltage of the Aircon capacitor

Another way to do it requires more technical skills. It is to test the voltage of a capacitor using a multimeter. A capacitor that is functioning will not deviate from the desired range of voltage.

Steps to repair an Aircon capacitor

Assuming that your Air-conditioner is a non-inverter unit. And that you have correctly diagnose that it is the capacitor that is faulty. Here are the steps to repair it.

1. Turn off the Aircon condenser unit

Before you do any Aircon repair. The first thing to do is always to off the main switch of the Air-conditioner. For newer hdb units, condo apartments and landed house. The switch is usually located at the aircon ledge. However for older hdb flats. The main Aircon switch is located inside the house, near to the window of the Aircon condenser. Aircon condenser refers to the bulky unit located outside the house.

2. Open the condenser cover

The condenser cover is the metal cover that protects the condenser unit as a whole. Most of the time you will only need to remove the top portion of the cover in order to access the capacitor. However, there are some models that requires you to remove the entire cover panel. For example Mitsubishi Aircon (non-inverter model), might require doing so. You might also encounter difficulty in removing rusty screws.

3. Check the wiring of the old capacitor

If the wiring is in bad condition. Changing the Aircon capacitor can be incredibly dangerous. You might have to engage a professional Aircon technician instead. Nevertheless, you have to check if the wiring connected the capacitor is in good share. Which means you shouldn’t be able to see the inner parts of the wiring. Once you have establish that the wiring is good, you can move on to the next step.

4. Remove and replace the capacitor

It would be best if you can wear a professional gloves to prevent static when in contact with the capacitor.  There is usually a clip holding on to the capacitor. Hold on to the clip and remove it. Then carefully replace it with the new Aircon capacitor that you have purchased. Finally, place back the Aircon cover. You will also have to make sure that it is tightly screwed.

5. Test the Aircon unit

After making sure that all the cover and screws are properly tightened. You can then proceed to turn on the Aircon unit again. Upon turning on, you should be able to hear a tick sound. This tick sound would indicate that the compressor has cut in. You Air-conditioner should be working upon hearing this sound. After a minute or two the compressor should be running by then. Nevertheless, if your Aircon is still unable to run. It might be due to a jam up compressor. Hence you might have to contact a professional aircon technician to assist you in this.

Aircon Capacitor FAQ

How do we repair and aircon capacitor?

Nobody repairs an Air con capacitor. It requires extensive manufacturing of it. Hence a new capacitor will be used instead.

What type of capacitors are there?

Capacitor comes in all shapes and sizes. For Air-conditioning capacitors. The range is from 20UF to around 60UF.

Aircon capacitor price. How much to repair aircon capacitor?

The price for replacing a capacitor will depends on the UF of the capacitor. And the difficulty involved in replacing it. It will cost from $120 to $180.

How often should you replace AC capacitor?

You shouldn’t be replacing the Aircon capacitor unless it malfunctions. Replacing the AC capacitor will not prolong it’s lifespan. There can be a multitude of issue that is causing the capacitor to malfunction. That being said, a brand new capacitor still has a longer lifespan than a used Aircon capacitor.

What are the signs of a bad capacitor?

For a non inverter Aircon unit. If the fan motor is running but the compressor is not running. It could be a sign that your Ac capacitor is not functioning. However for an inverter ac unit. You will have to measure the voltage as the Aircon capacitor is built into the motherboard


Typically, we advise most home owners to seek professional help to troubleshoot Aircon, Especially on Aircon capacitor issues and the replacement of it. Because capacitor is a dangerous electrical equipment and you have to handle it with care. Our trained technicians will troubleshoot your Aircon issue for you and replace it for you. Call us at 96515152 if you need a check on your Aircon unit.

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