FAQ for Aircon (Servicing & Maintainence)

I have decided to do up a FAQ for issues that aircon units commonly face.
These are for units that are in operation for a period of time, not for newly installed units.

Q.  Why my indoor unit aka blower/fancoil leaking water?
A1. Can be caused by a blocked drainage pipe by jelly or dirt.
      The fancoil internal drain pan is dirty causing water not to discharge properly.

If the drainage pipe or internal dirty, a normal servicing will be sufficient to solve the issue.
They will use a vacuum cleaner to clear the clogged drainage pipe.

A2.  The fancoil coil is choked causing condensation or icing.
If the internal coil is choked, u have to do a chemical cleaning to solve the issue.
For chemical cleaning, the technician has to go to the outdoor unit aka compressor to some people to recover the gas in the system 1st, followed by dismantling the whole blower unit down.
They will then dismantle the fancoil apart and wash the parts with water & chemical.
After washing, they will fix back everything & do a air purge/vacuum & test run the system again.

A3. The system have gas shortage issue causing icing. 
Need to check the gas level & top up to required pressure.
Topping up of gas is not normal & will be explained further later.


Q.  Why my unit is not cooling the room down?
A1. The unit is dirty.
Need to service it.

A2. The system have gas shortage issue causing insufficient cooling. 
Need to check the gas level & top up to required pressure.
Topping up of gas is not normal & will be explained further later. 


A3. Outdoor unit might have a faulty part.
The outdoor unit have a few parts which plays an important part in supplying gas to the room.
Expansion valve : controls the amount of gas to each individual fancoil unit.
PCB: Controls the valve & other parts by sending signal to them via feedback from the indoor fancoil pcb.
Fan motor : Blows out the hot air generated by the compressor & coil.

A4. Indoor unit might have a faulty part.
Air sensor : senses the room temperature & sends signals to the outdoor pcb to tell the compressor to cut off/stop working when room temp set on yr remote is achieved.
Thermistor : Senses the gas temp in the copper coil & feedback to the pcb, similar to the sensor.
PCB : Brain/control unit of the indoor unit & communicate with the outdoor unit.

Q.  The indoor unit is noisy.
 A1. Can be caused by a noisy fan motor.
The fan motor spins the rotor to churn out the cool air. 
If the noise level decrease if u set the fan speed to lower, most likely its the fan motor causing the noise.
Need to replace the fan motor.

A2. Can be caused by a choked cooling coil/choked rotor.
U will hear some uneven airflow sound after u on the aircon for 10-15 mins.
As the coil/rotor is choked, air will not pass through smoothly which explains the uneven airflow sound. 
Need to do normal/chemical cleaning.

Q.  The outdoor unit aka compressor is noisy.
A1. Can be caused by a noisy fan motor.
Need to replace the fan motor.

A2. Can be cause by loose parts due to them rusting/corroding over time.
Certain metal parts holding the outdoor unit together might have corroded, causing noise during operation.
Can replace the parts or consider replacing the outdoor unit/whole system is system is deem unserviceable due to old age.

A3. Can be caused by a noisy compressor.
All compressors are covered by a 5 years warranty. However this warranty usually cover parts only & not the labour.
U need to engage the agent to come & replace for a fee.
Price ranges from $350-$500 to replace the compressor.

Q.  Operation light flashing.
A1. Different brands of aircon, when experiencing malfunction will have a blinking operation or timer light.
Need to get a technician to diagnose & narrow down the possible faults.

In my opinion, an aircon system when used daily > 6 hrs will have an average lifespan of 5-8 years.
Anything major repair that needs to be done after 8 years, do consider to have the whole system replaced to avoid further repairs.
When replacing the system, best to replace the piping together if possible to avoid any complications with the new system.