Why you should never do aircon chemical wash?

“But I Just Did Aircon Chemical Wash Last Month? Why Did You Quote Me Overhaul Again Now?!”

These were the words we heard from one of our customers. They thought we were trying to scam them. It is not easy for residential Aircon contractors to explain to our customers. Hence we dedicate this page to explain why is their Aircon not cold After chemical wash? Furthermore we will point out to you why you should never do Aircon chemical wash.

chemical wash
Silverback Aircon

Finding Aircon chemical cleaning in Singapore?


For instance, if you are reading this, you are probably facing a dilemma in aircon chemical cleaning. Hence, this article covers a discussion on the difference between aircon chemical wash and chemical overhaul, with a clear explanation of what each of this aircon service is about. To start off, Aircon Chemical wash is the wash of the air conditioning fan-coil unit using chemical agent. When aircon normal servicing is insufficient to improve its condition or functions. We then recommend washing your Aircon with chemical. It is because, chemical wash involves removing the external cover and using chemical agent to wash the evaporator coil.

While it may seem like a simple and cost-effective option for maintaining an HVAC system, chemical wash is generally not recommended for a number of reasons. Hence, by reading this article, you will be able to know what are aircon chemical overhaul and aircon chemical wash. Furthermore, you will be able to understand which is the preferred option.

Refer to the table of content below.


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What is Aircon Chemical Wash?


The process of Aircon chemical wash includes the cleaning and checking of internal components. Firstly, we remove the air-conditioner cover and dismantle the system. We then proceed to wash the Aircon filter with water and chemical solutions. Following which, we use high pressure jet to wash indoor evaporator coil, drainage tray, front panel and cover. We then used Chemical-based cleaning solutions to remove dirt, oil and dust from the components of the fancoil. The chemical solutions also contain ingredients that kill and inhibit further growth of molds and harmful bacteria.

We will also clear the drainage pan and drainage system via vacuuming. In addition, we check on various functions. Such as fan bearing, lubrication, compression suction and discharge pressure. We also tighten electrical contacts if necessary. Once we finish cleaning all the components , we fix back the entire system.

aircon chemical wash service

What is Aircon Chemical Overhaul?


In the event that simple cleaning techniques and chemical washing is insufficient to clean the air conditioning system thoroughly, professionals may recommend a chemical overhaul. In the event that you have damaged components. we can also offer repair services in addition to chemical overhaul. Thus, if you wish to discover more about whether aircon chemical haul is necessary for you, visit our Aircon Chemical Overhaul page by clicking HERE.

Likewise, the process of chemical overhaul starts with turning on the Aircon. We then lock down the gas and remove the cover.  After inspection, the entire air conditioning unit is removed and dismantled into internal components such as the PCB, fan, motor, blower wheel, drain pan and evaporator coil.

Moreover, these components are checked and washed with chemical solutions that get rid of grime and mold. Common fixing procedures done during chemical overhauls include the replacement or lubrication of fan bearings to reduce operational noise and increase efficiency or the checking and monitoring of thermostat controls. Then, the parts are reassembled after the repair. Lastly, the air conditioning unit is fixed back to the wall and the air conditioning gas is turned on.

chemical overhaul service

Price of Aircon Chemical Wash


Types of service Price of servicing
Normal Aircon Chemical Wash  $80/ unit
Aircon Chemical Overhaul $130 / unit ( Cheaper per unit for 2 or more)
Ceiling Cassette Chemical Overhaul  $260/ unit ( depending on difficulty of job)
Chemical Wash for Cassette Unit $180 / unit

What is the Difference Between Chemical Wash and Chemical Overhaul?


Basically, the biggest difference is that, chemical overhaul requires dismantling of the entire fan coil unit. Even so, the motherboard will be removed from the evaporator coil. Whereas chemical wash will merely wash the evaporator coil by removing the fan coil cover. Maximum water pressure will also be used during chemical overhaul. Where as Furthermore, the back tray portion of an aircon unit can only be accessed by chemical overhaul.

Step-by-Step Guide to Aircon Chemical Wash:

  1. Remove Aircon cover
  2. Attach plastic sheets to Aircon fan coil unit. Water from the fan coil unit will be directed to a pail
  3. Cover fan coil unit’s electrical component and prevent water from entering
  4. Spray chemical agent on the fan coil and blower wheel
  5. Use high pressure water jet to wash away chemical agent

Step-by-Step Guide to Aircon Chemical Overhaul:

  1. Turn on Aircon unit and make sure Aircon compressor is running.
  2. Pump down Aircon gas to keep Aircon gas inside condenser unit.
  3. Remove fan coil unit.
  4. Dismantle fan coil unit completely
  5. spray chemical agent on evaporator coil and blower wheel.
  6. Use high pressure water jet to wash chemical thoroughly on evaporator coil and blower wheel.
  7. Assemble the fan coil unit back and install back.
  8. Release gas back into the system.

Why You Should Never Do Aircon Chemical Wash?

Chemical Agent Can Corrode Your Fan Coil Unit


Particularly, if you were to use chemical agent to wash your fan coil unit at the top, you will not likely be able to thoroughly wash away the residue. Because if the technicians put on too high of a pressure, your surrounding area will all be wet. Hence there might be residue left on your fan coil unit. As a result, it will corrode and result in damage coil. By all means, you can refer to the image attached at the side. In effect, your evaporator coil will be able to properly absorb heat and give out cool air to your room. If you chemically wash your coil too often at the top, you might have to change your coil entirely due to damages done by the residue.

damaged fancoil unit

It Can Never Wash Your Fan Coil Unit Thoroughly


We have encountered many customers and propose to do chemical overhaul to them. In which they responded “ We just did chemical a few months ago!” Here’s the issue, Chemical wash is not cheap (as compared to normal Aircon servicing). So if you have just done chemical wash a few month ago, you will definitely feel cheated if another technician recommends aircon chemical overhaul. However, normal chemical wash will not be able to properly wash the grime stuck between the coil.

For instance, have you ever encountered a toilet bowl that wasn’t clean properly after flushing? And you are only able to wash it away with water jet. Significantly, it is the same for aircon fancoil unit as well. Those grime and algae requires extremely strong water pressure to get rid of them Besides, we can only wash the area under the coil if we dismantle the entire unit.

Hence, we recommend doing chemical overhaul instead of chemical wash.

dirty fancoil

Chemical Wash Will Not Be Able To Wash Your Back Tray


Evaporator coil is V shape. Because if the coil is straight and flat just like the old aircon units in the past. It will take up a lot of space in the room. Therefore, fan coil in the current times are V in shape. Hence, as the evaporator coil condense, the water along with the dirt will flow into the back tray. This area can not be vacuumed and cleaned normally. We will have dismantle it fully in order to properly clean it. The dirt will accumulate in this area (albeit at a much slower rate than your drainage pan). Consequently, a choke at the back tray will result in water overflowing from there and you will have water leaking problem from your fan coil.

dirty backtray

Potential Damage To Your Electrical Components


Even though chemical wash is covered under warranty,  it might still  cause damage to the motherboard or other electrical components at the fan coil. Hence, the Aircon company will have to take time to find spare parts to replace for you, resulting in days without Aircon. Nevertheless if you are need of emergency Aircon repair, we can do a tele-consultation with you and arrange for same day Aircon repair.

aircon pcb


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Aircon Not Cold After Chemical Wash?

As hypocritical as we sound, we still do chemical wash when customer insist on it. Even though may not think that is the best solution to your Aircon issues. We’d still provide that service upon request. Nevertheless, we really recommend doing chemical overhaul instead of chemical wash. If your Aircon is not cold after chemical wash, there are a few things you will have to check.

Check if your Aircon Compressor is Running


If your aircon compressor is not running, the compressor won’t supply refrigerant to the evaporator coil. Normal Aircon chemical wash will not affect the compressor’s functionality. So if you Aircon compressor stops working after a chemical wash. It is likely that the electrical components in the condensing unit have malfunctioned at the same time. Thus, you can listen to the sound of the condenser unit to tell if it is still running.


Check If You Have Sufficient Refrigerant


It is very likely that you will not have the right tools or experience to do so. What you can do is to place your hand over the evaporator coil. If it is cold, your refrigerant is most likely sufficient. While If you feel that that the “coldness” level is not adequate,  it might be that the technician has forgotten to do an Aircon gas top up after chemical wash.


Check If You Have Sufficient Refrigerant


It is very likely that you will not have the right tools or experience to do so. What you can do is to place your hand over the evaporator coil. If it is cold, your refrigerant is most likely sufficient. While If you feel that that the “coldness” level is not adequate,  it might be that the technician has forgotten to do an Aircon gas top up after chemical wash.

chem wash

Conclusion: Opt For Chemical Overhaul Service Instead


If your aircon is not cold after chemical wash, it might be a better option to go over Aircon chemical overhaul instead. Intuitively, you might even think that the next aircon technician that recommends chemical overhaul may be scamming you. However, the dirt and grime deep inside the evaporator coil will still be dirty without chemical overhaul. Hence, our professional opinion is : ALWAYS go for chemical overhaul when in doubt. For more information of our Aircon servicing or chemical overhaul pricing. Call 96515152 for more information.


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Aircon Chemical Cleaning FAQ


Is chemical overhaul or chemical wash better?

 Chemical overhaul is a more extensive form of chemical cleaning for your air conditioning units. The entire air conditioning unit would be dismantled into the internal components such as PCB, fan motor, blower wheel, drain pan and evaporator coil. Such internal components are then checked and washed with chemical solutions which rids of grime and mould.

How much is chemical wash in Singapore?

For silverback aircon, we charge only $80 for each unit of air conditioner on every chemical wash.

How often do you need chemical wash in Singapore?

You should get a chemical wash for your air conditioner in the 3 common scenarios.

1. if the aircon no longer produces cold air

When the aircon is full or dust and dirt, it begins to produce little to no cooling air. Most of the time, this is caused by heavy ice accumulation in the condenser.

2. if the aircon is leaking water

A leaking aircon is often the result of a back flow that occurs when the unit’s drainage pipe has been clogged up.

3. if the aircon starts producing a foul smell

When the air conditioner produces a very strong stench, you shouldn’t worry as it is most likely to just be a case of a lot of bacteria build up inside your unit. This situation does render a chemical wash.

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