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Things You Need To Know About Your Aircon Unit PCB

What is an aircon PCB?

The aircon PCB or Printed Circuit Board is the part of your aircon unit that controls the working temperature. It contains electronic components such as transistors, resistors, and capacitors often in the form of surface-mounted devices (SMDs).

It is used with heat sinks to dissipate heat from the aircon unit using blowers. This allows for low energy consumption when compared with traditional systems. The main purpose of the PCB is to regulate current or voltage. Most often, when you need to fix an aircon unit when it isn’t cooling anymore, then this is the main reason.

Most brands use bigger PCBs for their systems, which can also control central heating or ventilation. But other brands use smaller PCBs for their ‘mini-systems, which can only cool and not heat your house.

How does an aircon PCB work?

The aircon PCB uses a Peltier Effect to create cooling by running an electric current through the small surfaces of the TEC or thermoelectric cooler. Since this Peltier effect creates a cold side and a hot side, it will consequently try to even out its temperatures and turn off itself before overheating or even going into the fire. It is important that you never touch this surface or let anything get in between them.

Most aircon PCBs have a fail-safe fuse installed between them and the rest of your electrical system. This will prevent any sort of damage and is very important to check and replace when you suspect that there might be a problem with it or with any other part of the PCB itself.

How long does a PCB last and is there a warranty?

Most aircon PCBs can last up to 2 years but are also dependent on your usage of the aircon unit, quality of use, and surrounding environment. Warranty varies depending on manufacturer’s policy and most only do 3 months or 1-year warranty which you need to pay for in order to get service from them when needed until such time that it fails completely.

How do I repair an aircon PCB?

It is difficult and will probably need a professional to do it. However, if you decide to go for it anyway, then be very careful and try not to touch the cold side of the small blue squares at any cost.

How do I know if my PCB needs replacement?

A replacement can go as far as repairing it, but most often, the aircon PCB won’t turn on anymore or it will show strange errors like F02. These aircon issues mostly happen after the PCB was overheated and therefore destroyed itself, so this is why we always recommend replacing it once found faulty.

What happens if a faulty aircon PCB won’t be replaced?

As mentioned, once the PCB itself or its components get destroyed by overheating rods/bolts, the aircon unit will no longer work. This might also lead your aircon unit to catch fire if it is left running, which can burn down your house or cause major damage. So, never take the risk and always replace your faulty aircon PCB as soon as possible.

Signs that your aircon PCB is damaged:

3) Aircon fan is unstable or stops running mid-way.

4) Buttons are defective, LCD working but nothing displays.

5) There are unusual sounds coming from the PCB which you’ve never heard before.

Pro 338 Note: The aircon PCB can also be damaged by dirty filters and low refrigerant levels which need to be checked and fixed as soon as possible. Dirty filters will eventually burn the PCB and a low level of coolant can cause it to overheat and explode.

Here are other facts about your aircon PCB:

1) Water can damage your aircon PCB if it is not dried properly. If you are making any repairs to the aircon unit, make sure that there are no damages on the printed circuit board, or else it could also cause short-circuiting issues later.

2) You should not try to wash or clean your aircon PCB using water because it may damage some parts inside which you cannot afford especially if there is a warranty left on your unit since the water might flow into the PCB board and cause your warranty to be void. So it is best to send your aircon unit for a service instead of risking your warranty coverage.

3) It is important to remember that even a small nick on its surface would leave you with all sorts of aircon issues. So if you have to do some work with the wiring around your aircon unit, be sure that you don’t hit any wires at all, or else it will leave you dealing with more aircon issues than just trying to fix the aircon unit itself.

4) It is recommended to get the PCB board serviced annually or after 1,500 hours or about 3 months of use. The aircon unit will not stop working entirely but it is the best way to make sure your aircon unit won’t break down on you during peak periods.

5) The aircon will take more than 1 hour to cool your room and cooling time varies depending on the size of the room/area where you are located in Singapore. However, if it takes 5-10 minutes, then this might be caused by a malfunctioning aircon PCB which should be serviced immediately before any other parts break down.


It’s always a good time to talk about the common issues that aircon units have. This way, you’ll be able to spot if there are problems with your unit or not and prepare for its replacement accordingly. If you require our aircon servicing services, Whatsapp us at +65 9222 4141 for a fast and transparent quote.

338 Aircon Servicing Singapore provides an extensive range of Aircon Services including Aircon Servicing, Aircon Repairs, Aircon Installation of the best aircon brands, Chemical Overhaul, Gas Top-up, Aircon Leaking Water, and Aircon Not Cold Fix, and more. We have a team of professional technicians who are equipped with vast knowledge and experience in the Aircon industry.

We have over 15 years of experience in dealing with aircon works and have completed thousands of aircon works for both residential (Landed, Condo, and HDB) and commercial. We are a highly recommended Aircon Company in Singapore, with many delighted customers and reviews over the years on Google and Facebook.

WhatsApp us at +65 9222 4141 for a transparent quotation and honest pricing for all your aircon needs or Call us at +65 9222 4141. We offer a fast and efficient service to serve any of your aircon needs!

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