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Air Conditioner Problems FAQ

Air Conditioner Problems FAQ

Common air conditioner problems FAQ

When the air conditioner starts to have problem, some problems can be easily fixed by the users themselves but some problems require the help of a professional.  Therefore, it is good to find out what is causing the problem first before you consult a professional.  In this post, we try to provide a list of common questions that air conditioner users may encounter when their aircon have problems.  We also try to provide solution to the problem if we think that it is easy for the user to fix the problem without the need to engage a professional.  One of our most useful guide for DIY checking and problem solving come with pictures and video and this can be found in question number 2 below.

FAQ on air conditioner problems for Indoor Unit




1. Why is the air released from the air conditioner outlet not cold ?

Some of the common causes for air conditioner not cold include but are not limited to :

  • Wrong remote control setting – setting temperature too high or not setting temperature to COOL mode.
  • The capacity of the aircon installed is too small for the room.
  • Air conditioner parts (eg filter, fan motor, evaporator coil, etc) are dirty.
  • Air inlet/outlet of FCU or condenser has been blocked by objects.
  • Fan blower is blocked with dust causing cool air to be blocked and can’t be released or blown out.
  • Certain parts in the aircon is faulty.
2. Can you do a DIY check on why your air conditioner is not cold?

Yes you can. Just follow CitiCool’s DIY Aircon Checking Guide.

3. Why the fan coil cannot start when you try to switch it on?

Some common reasons why you can’t switch on the fan coil include:

  • Remote controller is faulty or its battery is weak and need replacement.
  • Fan coil receiver/infrared ray is faulty.
  • Fan coil have no power supply.
  • Power supply trip in the premise.
4. Why the remote control can’t switch on the air conditioner?

This could be due to any of the following problem:

• Printed circuit board of the remote control is faulty.
• Printed circuit board of the fan coil is faulty.
• Fan coil receiver is faulty.
• Broken Wire.

To check whether the problem lies in the remote control or fan coil, test the remote control by using it to switch on other fan coils units.

5. What causes the air conditioner to switch OFF on its own and the indicator light keeps blinking?

When the indicator light keeps blinking, it is a symptom that the aircon is faulty. Therefore, the air conditioner starts to switch off on its own. You are advise to seek a professional aircon technician to troubleshoot on how to resolve the problem.

6. What cause the air conditioner to switch ON and OFF on automatically?

The indoor printed circuit board which controls the operation of the fan coil is faulty already. You will need to replace the printed circuit board.

7.  Is it possible to repair faulty printed circuit board (“PCB”)instead of replacing it with a new one?

Most of the time, it is possible to repair faulty PCB. However, the decision on whether you should repair or replace the PCB depends very much on the cost effectiveness to do so. Normally Citicool will advise client on which part is faulty. We will advise client whether it is more cost effective to do a repair or replacement. Normally, our advice depends on the age and condition of the PCB and the part that is faulty.

8.  Why your remote control doesn’t show the temperature setting?

This is because the remote control only show the temperature when it is set to COOL mode.

9. Why does the fan coil indicator light switches from two to one lighting?

This happens when the room temperature has reached or is closed to temperature setting in the remote control. It could also be due to wrong remote control setting.

10. How to cool the room at a faster speed?

To cool the room at a faster speed, just switch the remote control to a high fan speed for the air conditioner to reach the temperature faster.

11. What causes water to leak from the fan coil?

When installing air conditioner, a drainage pipe build into the fan coil to help carry water from the fan coil to the nearest drain available. Therefore, the drainage pipe helps to transport and discharge water from the fan coil. Once the drainage pipe is accumulated with too much dirt, water will start to build up in the blocked area of the drainage pipe. Since the water can’t be transported away to the drain, soon it will overflow and leak out from the fan coil instead.
When installing air conditioner, it is important to make sure that the running of the drainage pipe from the fan coil to the drain is done with a proper gradient. This is because poor installation of the drainage pipe can result in water leaking problem.

For more information relating to aircon leaking water, refer to the following page:  FAQ on aircon leaking water

12. What causes ice to form on the fan coil unit?

Either there is insufficient refrigerant or the air filters, cooling coil or fan motor are dirty.

13.  What makes the fan coil unit (FCU) to produce a foul smell?

The FCU does not produce any odour on its own. Generally, bad odour is absorbed into the FCU over time and the smell is discharged through the air flowing out from the air outlet.

Usually, the smell comes from mold and mildew that grow on the evaporating coil and drainage pan. As the mold and mildew proliferate especially when there are abundant of moisture, it will discharge foul smell through the air outlet. This is the reason why aircon servicing is required to maintain the cleanliness of the air conditioner system for it to release clean air.

14. What causes the fan coil unit (FCU) to become noisy?

Normally, if the fan coil become noisy, most likely the internal component such as the blower or evaporating coil is dirty and require either general servicing or chemical wash.




FAQ on air conditioner problems for Outdoor Unit




1. What causes water to drip from the condenser?

It is very normal to see water to dripping from the condenser. This happen when the air surrounding the piping condense. (i.e. turning from gaseous form to the liquid form). To prevent the water from dripping onto your neighbour’s outdoor unit, you can install a drainage kit.

2. What causes the condenser (outdoor unit) to become noisy?

There are many factor leading to the outdoor unit becoming noisy.  Some of these include but are not limited to:

  • Loosen parts, loosen wire or screws not properly tightened.
  • Absence of rubber padding beneath the outdoor unit.
  • Leakage of refrigerant or refrigerant valves are damaged or sound from refrigerant pipes vibration.
  • Compressor is worn out or faulty.
3. What causes the condenser to stop operation while the fan coil unit is still operating ?

Once the room temperature reaches the temperature set in the remote controller, the condenser will stop operating. When the temperature in the room rises, the condenser will resume its operation again.

4. When do you need to perform pressure test on an aircon system?

If your aircon always have gas leakages, there is a need to identify the leaking area and seal it up. Pressure test is use to identify the section where the leaking take place. This is done by inducing high pressure into the condenser, fan coil as well as the piping of the refrigerant. Once the location of the leaking is identified, the technician would need to perform repair work to seal the leakage area.




Some articles relating to air conditioner problems

FAQ on AC Condenser noise and repair 

FAQ on aircon leaking water

When does your aircon requires chemical wash?

What you need to know about aircon gas top up?

If you have a question relating to your air conditioner but couldn’t find the answer in the list of FAQ provided above, do feel free to give us a call.

Contact Us

Office Mainline No: Tap no. on hp to Save no. 6876 0581

Whatsapp No: Tap no.  on hp to Call  9272 6997

Air Conditioning Service FAQ

Air Conditioning Service FAQ

Air Conditioning Service FAQ

Instead of engaging an air conditioning service company to do the job, you may like to check if there is any DIY aircon checking or cleaning you can do by yourself.  Yes, there are many things that you can actually do on your own.  However, you may need some guidance.  In this page, we provide lots of useful information relating to DIY cleaning and DIY checking on your aircon problems.  Read the questions and answer in this page and you will definitely be more knowledgeable on your air conditioning service requirements

Air Conditioning Service FAQ – General Aircon Servicing


 1.  Can I perform a DIY general air conditioning service at home?

You may be able to perform certain steps such as opening and removing the fan coil cover and air filter for cleaning. However, some people find it tough to remove the water tray and air blower. Cleaning the evaporator coil is not an easy task for most people as it need to be done at height. While cleaning the cooling coil, you will definitely be exposed to dust and dirt flying all over unless you do it with proper technique. Therefore, DIY general air conditioning service is not appropriate for people who are allergic to dust. People with such allergic may fall sick due to exposure to dust while cleaning the air conditioner.

As for vacuuming of drainage system and checking of refrigerant level, you would need to have the proper equipment and knowledge to do the job. As it is quite tough for a layman to perform general air conditioner servicing, it is more advisable to engage a professional to perform the entire job for you.

 2.  What is the cheapest way to maintain you air conditioner regularly?

You can engage CitiCool to do the general air conditioning service for you. Note that if you sign up a service maintenance contract to engage CitiCool to clean your air con at least twice a year, the pricing come with a very good discount. That is why most of our existing customers rather sign a service maintenance contract with us.

If you are not engaging an agent for your air conditioning service on a monthly basis, You may want to DIY some basic steps of the servicing yourself on a monthly basis.

You can also watch our video to see how we do general air conditioning service. Normally, it is quite easy for you to regularly remove the air filter and clean it with water and brush away all the dirt and dust. However, if you are sensitive to dust, it is advisable not to do it yourself.

My air conditioner is not cold. Can I do a DIY check to determine what is the problem?

Yes, you can do a DIY check on your air conditioning problem. We provide step by step guidelines on how you can do so.  Refer to this page for a clear guide:   Aircon DIY Checking

 3.  Your air con is new but there is a smell coming from the air con. What should you do?

Certain brands of air conditioner may have this problem. The advice given is to switch the air con to fan mode for 15 to 30 minutes daily just before you switch off your air conditioner after using it. If you do this continuously, the smell will be gone between 1 to 3 weeks.

 4.  What is going to happen if you do have any air conditioning service done on your air conditioner?

Periodic air conditioning service helps to prolong the life span of an air con system. If you do not service your air con regularly, soon your air con will be accumulated with dust, dirt and debris. These pollutants will affect the efficiency of the air con in producing clean and cold air.  As the system start fighting with clogs and blockages to produce cool air, it will start to increase its energy consumption. As the situation worsen, your air con will start to have all kinds of problem such as water leakage, air discharge is not cold and the system becomes very noisy etc. Overtime, these problems will also contribute to components in the fan coil or condenser becoming faulty. Ultimately, both the efficiency and life span of the air conditioner will be affected.

5.  What is the recommended maintenance frequency for general air conditioning service ?

The appropriate frequency for maintaining your air conditioner depends on the extent of usage and the surround environment when the air con is installed. Generally, we recommend performing the following maintenance:

Home/Residential air con – perform general air conditioner servicing every 2 to 3 months.
Commercial/Office air con – perform general air conditioner servicing on a monthly basis.



Air Conditioning Service FAQ – Aircon Chemical Wash


6. Can you perform DIY for chemical wash?

When performing chemical wash, the entire fan coil unit must be removed from where it is installed. The whole fan coil unit needs to be dismantled so that individual components in the fan coil can be thoroughly treated with chemical solution. Thorough rinsing is required so as not to leave behind any chemical residue. Chemical residue trapped in the fan coil can corrode its components.

You also need technical knowledge and proper equipment to handle the refrigerant when performing chemical wash. The entire process is very complicated. Therefore, DIY for chemical wash is not advisable unless you have the relevant technical knowledge and equipment to do a proper job.

Watch our video below to see how Aircon Chemical Cleaning is performed:



7.  Why does the pricing for air conditioner chemical wash vary so much in different company?

Different companies perform chemical wash differently. It is important to check the scope of work included in the chemical wash process instead of just going for the cheapest rate. Beware of chemical wash that are performed onsite without removing and dismantling the entire fan coil unit. Such procedures are not advisable because it is difficult to remove chemical residue trapped in the fan coil by rinsing it onsite. Once the chemical are trapped in your fan coil, it will cause the parts in your air con to corrode.  Once the parts corrode, the fan coil will start to have all kinds of problem.  This will also shorten the life span of your air conditioner.

8.  Sometimes after chemical wash, the air coming out from your air conditioner is very smelly. What should you do?

This is because before the chemical wash, the fan coil unit already is already infected with mold or algae growing on it. The smell may not be so obvious to you before the chemical wash.  However, the smell becomes very obvious after the chemical wash although the chemical wash already help to remove these smelly substances. (Note that this normally happen only on certain brand of air conditioners.)

To get rid of the smell completely, you need to switch on the air conditioner and open the door or window in your room so that the smell can be dispersed off.  After a while (normally around 2 hours), the smell will be gone completely.

 9.  How do you know whether you air conditioner need general air conditioning service or chemical wash?

For residential unit, we would recommend our clients to perform chemical wash on their air conditioner at least once a year. However, frequency of servicing required really depends on the extent of usage. You can do a Do IT Yourself (DIY) Check to determine which is more suitable for your air conditioner.

Watch our watch on how to DIY check on what are the type of air conditioning services that your air conditioner requires.



Although CitiCool always provide lots of DIY Air Conditioning Service advice to our customers, our customers always come back to me for more questions or engage our service. You are always welcome to contact us if you have any query relating to your air conditioning service requirements.

Contact Us

Office Mainline No: Tap no. on hp to Save no. 6876 0581

Whatsapp No: Tap no.  on hp to Call  9272 6997

Air Conditioning Installation FAQ

Air Conditioning Installation FAQ

Air Conditioning Installation 

Due to the complexity involve in air conditioning installation, many people installing a new air conditioning system normally have lots of questions to ask.  Examples include which brand to buy, which model is good, which air conditioning installation vendor is reliable, which raw material to use etc etc.  Although detail answers relating to questions on air conditioning installation are posted on our website, they are found in different pages and post.  Everyday, we have many customers asking exactly the same questions relating to air conditioning installation.  To make it easier to everyone, we decide to compile the questions and answers for our reader under this FAQ on air conditioning installation. 

For people installing new or even re-conditioned air conditioners, this FAQ will definitely be very useful.  As a pioneer in the air conditioning industry, we hope that consumers are knowledgeable of the key factors to take note of before  making any final decision on their air conditioning installation.  The knowledge gain from the content below will definitely help you to make a more informed decision and help prevent unnecessary air conditioning problems which you may face in future. 

Can’t decide which brand of air conditioners or raw materials for your air conditioning installation? Yes, this is really a valid concern you should have.  Whether it’s air conditioners brand or raw material brands or even the vendor or installer, these factors can make a big difference to your future expenses on repairs and maintenance.  Therefore, do it right the first time.   Isn’t this what we were thought in total quality management?  Do find out more about your air conditioning installation below before making any decision.

List of FAQ on Air Conditioning Installation

Air Conditioning Installation FAQ – Components in an air conditioning system


What are the key components in an air conditioner system?

  An air conditioner system comprises of an indoor unit known as a fan coil unit and an outdoor unit known as a condenser unit. Both of these units are integrated by connecting pipes and wiring. A Fan Coil Unit (FCU) is known as indoor unit because it is installed inside your house or office premises as it is use to absorb heat and cool the surrounding indoor environment. The main component in the FCU is the cooling coil which is known as an evaporator coil. A Condenser Unit (CU) is also known as outdoor unit because is usually installed outside of the house . Heat absorb by the FCU is transferred to the condenser which releases it to the surrounding outdoor environment. The main component in the condenser is the compressor.

What are the key raw materials used in air conditioner installation?

  Copper tubing, Insulators, Wire, PVC pipe and PVC casing.

Why is it important to use high quality raw material in air conditioner installation?

  The types of raw material used in your air conditioner installation will greatly affect the efficiency and life span of your air conditioning system. Air conditioner installed with inferior raw materials will soon have lots of problems and will have a much shorter life span.

What are the main differences between window unit, single split unit and multi-split unit?
Window Unit: All the aircon components are housed in a single unit which is installed via an opening in the wall. Hence, there is no inter-piping or connection. Window unit are usually more noisy compared to split unit due to design.
Single Split Unit : Single Split unit is made of one indoor and one outdoor unit. The indoor unit is known as Fan Coil.  It helps to cool the room. The outdoor unit is known as Condenser.  It helps to disperse heat. Both the fancoil and condenser are inter-connected via piping.
Multi Split Unit : Multi Split unit has one condenser with two or more fan coil units. In other words, multi split unit is normally made up of multiple fan coils sharing the same condenser.


 Should you choose system 3 + single split or system 4 for your house?

A system 4 multi-split is definitely cheaper compare to a system 3 multi-split + single split.  This is because a system 3 multi split + single split system comes with 2 separate condensers.  However, if you SWITCH ON all the four units at the same time, the cooling capacity for a system 4 multi-split will not be as efficient as the system 3 multi-split + single split.  Therefore, if you intend to use all the 4 units at the same time, it is better to install a system 3 multi-split + single split.  (Note: For HDB, you must check whether the electrical loading is allowed.)

For example, you want to install a system 4 multi-split unit.  For example, you need to install air conditioners for a living room and 3 bedrooms.  As the living room is bigger, you will need say a 18,000 BTU fan coil or more for the living room and maybe 9000 BTU fan coil for the other 3 bedrooms.  In this case, if you on all 4 units, you probably find that all the rooms are not cooling enough for your expectation.  Based on our experience, once you on the air conditioner in the living room, you probably have enough cooling capacity left for 1 bedroom only.  Alternatively, if you are not using the aircon in the liviing room, the cooling capacity is likely to be sufficient for all the 3 bedrooms.

In conclusion, choosing a system 3 + single split or system 4 depends on your usage.  If you are not sure how many air conditioners you will need to on at the same time or not sure of the frequently of usage, it may be better to install a system 3 + single split to avoid having an insufficient cooling capacity problem in the future


Air Conditioning Installation FAQ – Aircon Brand, Types, Size & Pricing

What is the recommended or minimum air conditioner capacity required for your room?

  For HDB room, normally an air conditioner with BTU 9000  is enough for the room. You can also compute the BTU based on your room size. Recommended BTU/hr = Area of your room x 65 If you room size is a square room area is 15 feet X 15 feet, Recommended BTU/hr would be 15x15x65= 14,625

Which air conditioner brand is more popular or has lesser problem?

  Based on our experience handling different types of air conditioner problems, it is true that certain brands of air conditioner tend to be more reliable and has lesser problems. As a result, when our customers consult us to recommend to them an air conditioner that is more reliable and has lesser problem, we are very happy to share our experience with them. Examples of such air conditioner brands include but are not limited to Mitsubishi Electric, Daikin and Panasonic. Take note that even if you purchase a good brand of air conditioner, there is still a luck factor involved because normally out of the million pieces of aircond produced, there bound to be some units that may be faulty. Beside this luck factor, there are also a few other crucial factors determining whether your newly installed air conditioner is reliable and lasting. These key factors include:

• the quality of raw materials used for installing the aircon;

• whether the aircon is properly installed; and

• whether the aircon is properly maintained.

Note that proper installation is important as improperly installed aircon will give you problems such as water leaking or refrigerant leaking. Once these happened, you will have air conditioner not cold problem.

What is the difference in benefit between an inverter and a non-inverter air conditioner?

 The main benefit of an inverter aircon is its energy saving capability and reduced noise level compared to a non-inverter aircon. This is because the inverter aircon has an inverter circuit. This inverter circuit is able to regulate the compressor ‘s rotational speed, thus reducing its energy consumption and noise level.

What causes the price difference in the quotations you received for installing new air conditioner?

  When comparing quotations for installing the same brand and model of air conditioner from different vendor, it may not be prudent to just go for the cheapest. You should review the following factors which causes the price difference before you finalize which is a value for money deal:

• types and quality of raw materials used, especially the copper pipe, insulator and cable as pricing between quality and inferior raw materials can result in significant price difference;

• experience of installing team;

• reliability of the vendor; and

• vendor’s recommendation on how to run the piping.

At the very minimum, you should understand that it is very important to check the types of raw materials used in your aircon installation. This is because if you try to save money now by using inferior materials, soon you will need to fork up more when your aircon starts to have problems. This can become a nightmare for you sooner or later. This is the reason why CitiCool use only high quality raw materials for all aircon installation regardless of whether we are installing new or re-conditioned air conditioners. From any aircon servicing vendor’s point of view, when providing quotation, the two key cost factors are raw material and labour cost. Raw material cost relate back to the quantity and quality of raw materials used. Labour cost relate mainly to the complexity of the installation process. Basically, the more complex or more risky the installation job, the more man hour will be required.  Of course it is definitely better to use experienced installers.



Air Conditioning Installation FAQ – Aircon Installation Vendor & Aircon Life Span


 What are the risk involved when choosing an air conditioning vendor?

  It is important to choose a reliable and established vendor. We had a few customers who approach us because their newly installed air con has problem and they couldn’t find the vendor who installed the air con for them. Therefore, it is important to do a check and make sure your air con vendor is an established vendor. At the very minimum, check if they are registered with ACRA and has a physical address where you can locate them. There are many vendors that may have an address registered with ACRA but this is just an address use for ACRA registration. They may not have a physical location for their operation at all. There are also vendor who came in from the neighbouring country and do not have a specific company registered in Singapore. Beware if you engage such vendors because they may become missing in action when your air conditioner has problem and any warranty provided by them become worthless. Note that CitiCool is registered with ACRA. Our physical office has been located in Eunos Ave 7 for many years. We are also BCA registered and certified with a Bizsafe Star from WSHC.

How many days does it take to install an air conditioner system?

  Normally installation in HDB flat requires one full day. For Private and Commercial properties, the number of days taken to install the air conditioner system is dependent on the number of air conditioners to install and the complexities associated with the installation. Common examples of such difficulties include but are not limited to :

• accessibilities to exact installation site,

• height of installation,and

• extent of wiring and piping to run.

In CitiCool, we normally try to complete our installation project within one day if possible. We do so by deploying more manpower to the site.  Doing so we can help eradicate many inconvenience cause to the customers because some residential customers may need to apply for leave if they don’t have people at home to provide access to the installers or some may prefer to monitor the installation also.

How to prolong the life span of a residential air conditioner?

  The life span of a residential air conditioner actually depends but are not limited to the following factors:

• Whether the air con is installed properly

• Extent of usage;

• How often you maintain your air con;

• How well you maintain your air con;and

• The type of materials used for the air con installation.

If all the above factors are well taken care of, an air conditioner system can actually last more than 10 years. However, due to technological changes and advancement, people may change their air conditioner system after a few years.

Why is it better for air conditioner installer work in team?

  In our company’s opinion, for better installation result, it is better to have at least two experienced installers working as a team. Actually, it is very tough and difficult for one person to handle the job alone. This is especially when you need to work at height with heavy equipments and raw materials. Note that good and proper installation of air conditioners requires proper alignment of various aircon components at height. Therefore, team work plays a very important role in ensuring good and proper installation.



Air Conditioning Installation FAQ –  New vs Re-conditioned Air Conditioner


 What is the warranty for new vs re-conditioned air conditioner?
New Air Conditioner The warranty comes from the manufacturer of the equipment. Most manufacturer provide one year warranty for parts & labor.  Five years for compressor.

(Warranty only include repair service and exclude cleaning servicing). For the compressor unit, most manufacturer normally cover part warranty for a period of 5 years.
Re-conditioned Air Conditioner CitiCool offers 6 months Onsite Warranty. (Warranty exclude condition whereby the aircon is not cold due to dirts accumulation as dirty aircon need either general aircon servicing or chemical wash and these services are not covered in the warranty.)  Do check out for promotion where we provide extended warranty.
Should you get a new air conditioner or a re-conditioned aircon?

  For people that move into a new house, most would prefer to install new air con unless they have a budget concern. However, many people consider a re-conditioned air conditioner because they only need the air con for a short period of time or they are renting out the unit. If you are lucky, you may be able to purchase re-conditioned air con which are pretty new. Some people sold their air con after a short period of usage for different types of reasons. Take note that the key to getting clean and cool air is how you maintain the air conditioners over time. Therefore, to many people, it doesn’t really matter whether the air conditioner is new or old.  Most important is whether the air conditioner is able to cool the room to their expectation.

What brands of air conditioners are available in CitiCool?

  We sell all the different brands but we normally recommend to customers those brands which have lesser problems.  You can find out more from the articles below.

Some articles relating to installation of new or re-conditioned aircon

Which Aircon Brands Are Reliable And Have Lesser Problems? 

What Are The Reliable Brands Of Aircon Compressor?

What Are The reliable Brands of Aircon Condenser?

9 Tips On Choosing A Suitable Aircon For Your Home

Latest Technology To Look Out For When Buying A New Aircon

If you have any further questions relating to air conditioning installation, feel free to contact CitiCool on your query.


Contact Us

Office Mainline No: Tap no. on hp to Save no. 6876 0581

Whatsapp No: Tap no.  on hp to Call  9272 6997

AC Condenser Noise & AC Condenser Repair FAQ

AC Condenser Noise & AC Condenser Repair FAQ

What is an ac condenser ?


An ac condenser is an outdoor unit which houses the compressor.  It is so known because it is normally placed in an open area or environment. The ac condenser is basically a machine playing the role of a heat exchange or heat transfer.  In fact, if you ever walk pass an operating ac condenser, you will feel very hot because of the hot air being blown out by the condensing fan.  Actually, it is advisable to place the ac condenser in open and airy area because it will help in facilitating its function of transferring heat to the outdoor environment.  Some people even try to place their ac condenser under shady areas in their garden. However, note that it is important to make sure the ac condenser is clear of any debris or rubbish which may obstruct its heat transfer.

How does the ac condenser transfer heat?


Heat is absorbed by the evaporating coil (also known as cooling coil) found in the indoor unit (also known as fan coil).  The heat absorbed by the evaporator coil is then transferred via the refrigerant in the aircon system to the ac condenser for dispersion.  The ac condenser has a condensing fan which serve the purpose of blowing out the heat to the outdoor environment at a faster speed.

What causes ac condenser to be so noisy?


When your air conditioning system is on, there bound to be a small amount of bearable sound coming out from the condenser. However, sometimes you may start to hear different types of loud, wierd and unusual noises coming out from the condenser.  When this happens, most likely certain key component in the condenser is malfunctioning. The different types of noises produce by the ac condenser provide useful symptom telling you which part of the condenser might have problem. Before we go into further details, lets understand what is an ac condenser made of first.

An ac condenser is made of the following key components :

  • Compressor(s);
  • Condensing coil;
  • Fan motor;
  • Refrigerant/Freon Gas;
  • Solenoid(s) and
  • Valve(s) (flow control device);

All the above components are integrated with inter connected electrical parts, piping and tubes.  The minute any of the above components becomes defective, the condenser will start to produce different types of strange noise. The character of each type of noise produced by the condenser provides an indication on which component is not working well.  Next, we will try to classify the different types of possible noises that a problematic ac condenser can produce.


What are the common noises produce by a problematic ac condenser?


The following are some common noises you may hear coming from a problematic ac condenser.  The noise includes but are not limited to the following:

a. humming – a low continuous sound
b. hissing – a sound like a long “s”
c. buzzing – a long continual sound
d. rattling – a short sharp knocking sound
e. banging – a sudden loud noise
f. clicking – a short sharp sound
g. screaming – very loud high-pitched sound
h. squealing- a long high-pitched sound

Why does ac condenser produces humming sound?


If your hears a loud humming noise (i.e. a low continuous sound)  from your AC condenser, the problem could be due to:

  • the compressor cushion has worn off;
  • the compressor internal component parts has worn out; or
  • the compressor capacitor has become faulty.
Solution:  Once you ascertain exactly which of the above part is faulty, replace it with a new part.  You can also source for a used part that is still working.  Once the faulty part is replaced, the humming sound should stop.

Why does ac condenser produces hissing sound?


If your AC condenser produces loud hissing noise (i.e. the sound of a long “s”), there are two possible causes.  First, it is likely that there is an internal blockage in the condensing coil.

Solution:  Clean the condensing coil and remove all the clogs and blockages.

If you have diligently cleaned away the dirts and clogs on the condensing coil but the hissing sound problem is still there.  The next possibility is that there is a leakage of refrigerant or the refrigerant valves may be damaged.

Solution:  Once refrigerant is involved, it is more advisable to engaged a professional to diagnose and solve the problem.

Why does ac condenser produces buzzing sound?


If your AC compressor produces loud buzzing noise (i.e. a long continual sound), it is an indication of a more serious problem. Either the motor, electrical component in the condenser has failed or the wire in the condenser has loosen.

Solution: Dealing with electrical components poses a higher risk and danger as there is a possibility of fire risk. Therefore in the event that your AC produces loud buzzing sound, we would recommend that you to contact a professional to help you solve the problem instead of fixing it by yourself.

Why does ac condenser produces rattling sound?


If the noise is a rattling sound (i.e. a short sharp knocking sound) , there are several likely causes.

First, most likely there is some problem with the condensing fan.  However, if the above effort does not solve the problem, there is a likelihood that the fan motor bearing is burnt out or the starting capacitor has become defective.

Solution1:  For condensing fan problem – normally cleaning the fan or re-aligning the fan will solve the problem.  For defective fan motor or starting capacitor – replace the defective parts.

Second, rattling sound from the condenser can also be caused either by loose parts, or shaking of the internal tubes.

Solution2:  Tightening the loose parts will solve the problem.

Third, rattling sound could also be due to the refrigerant level is too high or the wrong refrigerant type being used.

Solution3: If the problem is due to wrong refrigerant level or type, it is more advisable to engage an aircon professional to diagnose and solve the problem.

Why does ac condenser produces banging sound?


If the noise is a banging sound (i.e. a sudden loud noise), there could be loosen parts, i.e. piston pin, internal mount or even the crank shaft in the aircon compressor could have loosen. This could be an indication that the compressor lifespan is almost up.

Solution:  Replacement of compressor may be required.

Why does ac condenser produces clicking sound?


If your AC compressor starts to produce a persistent clicking sound (i.e. a short sharp sound), it could be due to loose parts or dirty fan.

Solution1: Tighhen the loose parts and clean the dirty fan.

If tightening the parts and cleaning the fan does not work, then there could be a bigger problem such as the followings:

  • control board is damaged;
  • thermostat wire is shorted; or
  • thermostat is broken.
Solution2: Handling the above components is very dangerous due to high risk of electrocution.  Therefore your should contact a professional to perform troubleshooting and help with the repair or replacement of parts.

Why does aircon condenser produces screaming sound?


If your AC compressor starts to produce unbearable screaming sound (i.e. very loud high-pitched sound) it is normally due to strong internal pressure due to a number of factors such as clogging, failed bearing or motor failure.

Solution:  It is advisable to engage a professional to troubleshoot and check which is the reason for the screaming sound.

Why does your ac condenser produces squealing sound?


If your AC compressor produces loud squealing noise (i.e.a long high-pitched sound) , either the fan motor or compressor motor is in trouble. This could be due to the air con being overused or the lifespan of the fan motor or compressor motor is nearing its end.

Solution:  Replacement of fan motor or compressor may be necessary.


Engaging a professional to help repair or replace your ac condenser


CitiCool offers free troubleshooting service to identify the problem existing in your defective ac condenser. However, we do charge a minimal transportation cost which can be used to offset against the repair cost. We also sell both used and new ac condenser component and parts that you may need to replace to fix your defective condenser. Customers who try to save cost normally choose to use used parts to replace the damage part of their condenser. If it is more cost effective to replace your ac condenser, we also have second hand ac condenser available for replacement. Normally, we would advise customer with an old aircon system to replace their condenser with a re-conditioned unit instead of a new unit. This is more cost effective because just in case the indoor unit also start to have problem later, the owner may consider changing the entire system. In this scenario, it may not be advisable to replace the current ac condenser with a new one.

Feel free to contact us if you require our service.

Other Related Educational Tips to read

Air Con System Components That Are Non Replaceable

Educational Content covering Causes, Tips and Solutions for Aircon Problems

Educational Content covering FAQ on Aircon Conditioner Problems 

Air Conditioning Service Office Contact


Tap the number below on your handphone to contact us.


Office Mainline No: . 6876 0581


Whatsapp No: 9272 6997


Check our office and aircon workshop location on our contact page.


Air Conditioning Service Booking





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Aircon Leaking Water FAQ

Aircon Leaking Water FAQ

Is aircon leaking water a serious aircon problem ? 

Aircon leaking water (Indoor Unit)

If you are having a concern over aircon leaking water in your indoor unit, actually, it may or may not be a problem of concern.  For example, you may spot some water around the evaporator coil of the air conditioner (“AC”) unit.  There is no need to panic as this is actually due to condensation of the evaporator coil and this is quite normal.  Sometimes, you may even spot a small pool of water.  Actually, there is no need to be too worried also.

However, you need to have some concern if you spotted an abnormally big amount of water leaking from the fan coil.  This is really an aircon leaking water problem.  However, this problem can be solved easily with the help of an aircon technician.  Normally, its quite easy to solve the problem.  Let’s explore on where the problem lies so that you can understand the extent and type of work required to solve the problem.

What causes aircon leaking water problem?

Possibilities for aircon leaking water include but are not limited to:

  • drainage pipe is dirty or blocked;
  • drainage pipe not properly installed ; or
  • refrigerant level is too low

I:  Drainage pipe is dirty or blocked

One very common reason resulting in the problem of aircon leaking water is due to blockage in the drainage pipe. Whether you use the air conditioner frequently or not, there will be dust, dirt or debris accumulated inside the drainage pipe over time.  In fact, the higher the usage of your air con, the faster dust, debris and even mould will accumulate in the drainage pipe.  In addition, over time, the pipe may become rusty and cracks may form also. This is especially so if your air con is a very old system. Therefore, if you did not service your air con regularly, the accumulation of all kinds of debris in the drainage pipe will start to cause blockage.  This blockage in your drainage pipe is definitely contributing to your aircon leaking water.

II: drainage pipe not properly installed

If your air conditioning system is very new yet it starts to have water leaking problem, one of the likely cause is due to improper installation of the drainage pipe.  Some possible installation problems include but are not limited to:

  • the drainage pipe was not installed with a correct gradient
  • the drainage pipe was not connected correctly
  • the drainage pan was not fitted in correctly

III: Refrigerant Level is low

When the refrigerant level in your air conditioning system is too low, it will result in pressure which can cause the evaporator coil to freeze over. When the ice starts to melt, water will flow into the drainage pan.  An excessive amount of water flowing into the drainage pan will cause an overflow.  This will result in your aircon leaking water.

What to do if you have aircon leaking water problem?

Once you identify your aircon leaking water, the best thing to do is to switch it off.  Whenever there is water around an electrical item, there is hazard.  It is also better to turn off the air conditioner.  Otherwise, the aircon leaking water problem can accelerate in more problems causing further damages to your air conditioning system.  Therefore, it is advisable to switch it off and stop using the air conditioner until the problem is resolved.

Engaging  professional help to solve your aircon leaking water problem

If your air conditioner (AC)  system is newly installed, then it is very likely that the AC leaking water is a result of poor AC installation.  You should contact your AC supplier to do the troubleshooting since your AC should be still under warranty.

If you have been using your aircon for some time and have not been servicing it.  It is likely that your AC leaks water due to drainage pipe blockage.  The solution is either to perform a general aircon servicing or a chemical wash (also known as chemical overhaul) to eradicate the problem.  Which service to perform really depends on the extent of the blockages.  If you are not sure which is a better solution, you should engage a professional opinion.

In fact, there are certain risks involved if you try to solve the aircon leaking water problem by yourself.  Dealing with water in an electrical appliances actually involve danger, especially for a layman.  Do contact CitiCool if you need help.  We are just one phone call away.  Sometimes we are able to assess the likely causes and extent of the problem if you are able to provide us the answer to a few relevant questions.  Sometime, we may need to go onsite to perform troubleshooting before giving you the right advise.  Just feel free to give us a call.

 How to prevent aircon leaking water problem?

Prevention is always better then cure.  The following are some useful tips on how to maintain your aircon to prevent it from leaking water:

  1. Clean or change the air filter regularly. This can help to remove the dirt that may be blown into your drainage pipe.
  2. Service and maintain the cleanliness of drainage pipe regularly to prevent blockage
  3. Check that the refrigerant level is appropriate and not too low.

Further prevention also include:

  • Having an additional drainage pan to stall excessive water flowing from the existing drainage pan.
  • Having an additional drainage pipe (secondary piping) installed for usage in the event the existing one becomes clogged.

Other Related Educational Tips to read

Educational Content covering Causes, Tips and Solutions for Aircon Problems

Educational Content covering FAQ on Aircon Conditioner Problems 



Air Conditioning Service Office Contact

Tap the number below on your handphone to contact us.

Office Mainline No: . 6876 0581

Whatsapp No: 9272 6997

Check our office and aircon workshop location on our contact page.


Air Conditioning Service Booking

If you need any air conditioning service from CitiCool, clicking on the “Service Booking” button below.


Find CitiCool on the following social media

To know more about CitiCool, join as our friend on facebook or follow us on google plus below:

Facebook : https://www.facebook.com/citicoolaircon

Google Plus : Google+

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