My diakin system 4 inverter aircon is 10 years old. It spoilt recently due to inverter PCB board burnt and was replaced by Daikin vendor themselves. Saw a burnt mark on the old PCB board when the Daikin vendor returned the old PCB board to me. It was not a question of replacing the air-con as I need to understand the reason for the PCB board getting burnt in the first place. A couple of reasons based on my very limited knowledge and discussion with some aircon technicians. Firstly it maybe because of current surge that caused the burnt, but there was no fuse or other electrical parts getting burnt and also no signs of shorts anyway on the board(no dead lizard or creature). Furthermore there was no recent electrical trips in my house prior to the PCB board getting burnt as I could remember for the last 3 years. Secondly it maybe that the condensor coils were getting dirty due to a layer of dust(2mm) as there was no cleaning for 10 years, thus causing the compressor to work much harder to get rid of the heat due to clogging by the dust which reduced the air circulation. Thus as such I had to know the reason for the PCB board burnt. The alternative would be to sent the burnt PCB board to Daikin Singapore to diagnose the root cause and that maybe possible but I have yet to explore that option.
Daikin vendor suggested that I don't waste my money to either normal clean or chemical clean the air-con and just use it until it spoils as it is 10 years old. Yes, it is considered very good to have a Daikin inverter aircon running for 10 years old especially this particular model of MK75 which is known for inverter PCB board burnt or other components getting spoilt as I gathered from the 3rd party aircon technicians. This is not something that Daikin themselves admit to as I viewed it as possibly a manufacturing defect.
I wanted a 2nd opinion from another independant air-con vendor who suggested that a chemical clean be done for all the Qty: 02 used room FCU and the compressor which will costs almost $300 inclusive of refilling of compressor aircon refrigerant gas; he advised that a normal clean will be of little use I was in a dilemma because obviously I do not want to spend all these money to clean the air-con and subsequently have the aircon spoiled due to another PCB board burnt or compressor motor failure as thse are 2 common causes. My CFO(wife) also vetoed this suggestion to clean the aircon.
Left with no recourse I then bought concaire for $59 for HomeFix which allowed me to clean either Qty: 05 FCU or Qty: 04 FCU and Qty: 01 outdoor condensor. I cleaned the Qty: 01 master bed room FCU first by following the instructions on the big bottle very closely and ensured that I did not wet any electrical parts and also use a soft tooth brush to get rid of the stuck dirt in the fan coils and rotary fan blades first. I also re-filled the spray bottle with water about 15 mins after spraying the concaire chemicals onto the FCU coils and rotary blades fans to ensure that the chemicals are flushed out fully. Then I extend the plastic bag that is collecting all these dirty water under my aircon to collect the rotary fan water spray after I switched on the aircon. That night my wife commented that the aircon was very cold and powerful as she can feel the air from thes aircon blowing very strongly and far for the first time after so many years. Subsequently we monitored and observered the behavor over the next few days. Funnily she also set a the temperature to 29 degree celcius as she felt that the room was too cold. I told her to set it back to 28 degree celcius as a too high temperature may not be good for the aircon.
Once we confirmed there was no lingering problems after the cleaning over the next couple of days, I cleaned another room FCU and the breeze became strong and powerful once more. Finally I waited for a rainy day(so that neighbors don't complain) to clean the outdoor condensor by spraying the concaire solution onto the external coils of the condensor after I had use a soft tooth brush to remove the caked dirt on it. Then I rinsed with water using the spray bottle.
I'm a very satisfied customer of concaire. Currently after 1 month, the performance of the aircon remains strong and powerful. There is no corrosion or signs of the aluminium fins becoming brittle as I understand that concaire solution is very mild compared to CX488 which is commercially used for the purpose of chemical cleaning.
This is sharing my experience with concaire for those who wants to try DIY. It saves money and is very satisfactory when you realise that the so-called chemcial cleaning might actually weaken your aluminimum fins if done too often.
