Aircon water dripping

What causes aircon water dripping?
Your aircon, which is cold, will naturally produce condensation. Thus, all air conditioners have an inbuilt water collection tray, which is connected to a water pipe to discharge the condensate water. For more details pertaining to condensation, please read condensation.

Common Causes, watch video (Part 1, water dripping caused by Jelly):


Part 2: what is this “jelly” and “dust” that’s causing aircon problem

For reading:

A) 1st and the most common cause: Clogging of aircon drain pipe
Aircon water dripping is usually caused by choking of the air conditioner’s condensate drain pipe or aircon water tray. Look at the disgusting jelly! Wondered where these jelly (bacteria biofilm) came from? Please readWhat people do to sabotage their air conditioners (unknowingly)

aircon water tray full of slimy bacteria biofilm jelly
picking up aircon jelly using bare fingers
yellowish slimmed removed from aircon water tray
clear transparent jelly bacteria biofilm dangling off aircon fan coil

More disgusting “jelly”:

Bare hands holding a very long aircon jelly bacteria biofilm purged out from aircon condensate pipe in a toilet
a puddle of brownish jelly purged out of an aircon condensate pipe

Therefore, do not ask for general service when you have an aircon water dripping problem. At most, it will stop the leak for a short while, but most of the time, they don’t work at all. Furthermore, when the fan coil is so dirty as to choke the pipe, it is high time to give it a thorough cleaning, don’t mess with your health. The following pictures are taken from aircon that were regularly serviced, the owner took up a maintenance contract for a 3 monthly general servicing. Typically, the dirty water we collected from a proper aircon cleaning always looks like this, this is the air you breath everyday:

a tank og black water collected from washing of air conditioner fan coil
mold within a daikin aircon

B) 2nd cause: Ice forming on fan coil

icing on aircon fan coil

C) 3rd cause: Clogging of aircon internal drain tray
Choking at the back internal water tray of the aircon blower. (meaning; it is not choking the main water pipe nor the main water tray)

picture of the internal water passage way of a daikin aircon
inside of a daikin fan coil

D) 4th cause: Surface tension problem
The condensate water that is collected from the back internal water tray is funneled through to the front, but misses the front water tray. This is caused by surface tension problem.

As seen from the picture above, The blue color water droplet that i drew, represented by position “a” might be what some of us expect the position of a water droplet will be as it leaves the funnel. However, the water crawls backwards to position “b”. This is caused by a syndrome known as surface tension. Due to the crawling back effect of water, the water may miss the water tray, or it touches the tip of the water tray and crawls along the tray edges and out of the tray, dripping out of the tray. You will see water dripping from the aircon unit itself, but the amount of water is usually not as much as compared to water dripping caused by a choked water pipe.

This problem arises when stickers and sponge liked funnel extenders dropped off after technicians clean up the system or accidentally removing them. You will see the effect of having a sticker entension versus one without below:

Question 1:

Do you experience aircon water dripping problem during the first year of installation?

Yes – this means that something is wrong with the way the water pipe is laid. The soft flexible water pipe could be bending upwards as shown on picture below. Do you notice the pipe bending like an “U”? This area will readily trap dust and dirt and thus very prone to choking the aircon drainage system. Otherwise, as we often encountered; the entire length of the pvc pipe is laid too flat and in some case, even tilting slightly upwards.

aircon condensate pipe connector

Solution: If it is the soft flexible pipe that is too long and bending upwards, it should be shortened or replaced with a solid pvc pipe. Should the entire length of the pvc condensate pipe is installed with a bad gradient, and further assuming that reinstalling the pipes is not feasible, then, installing an external water pump can be considered. This is how the pump looks like:

aircon condensate pump
aircon condensate pump in an insulated box
aircon insulated condensate pump underneath an aircon

aircon water pump without cover  

Boxed up aircon water pump with sound insulation.

Do you experience aircon water dripping problem during the first year of installation?
No – this means that the water pipe is good enough to handle your aircon condensate water for at least a year. Then it is most likely due to choking by jelly liked substance as mentioned above.

Question 2: Icing problem
Try removing the filters to take a look at the fan coil, can you see if you can see ice forming on the right?

aircon cover lifted up
ice on aircon fan coil


If there is an icing problem and if it is severe enough, you may hear the sound of the aircon blower “cracking” as the ice gets larger. Usually water dripping will be intermittent. This happens when the ice melts when the compressor cuts off.

But if the icing problem is not severe, you will not hear any “cracking sound”, but will experience constant aircon water dripping, but usually less water as compared to a choked drain pipe. The ice interferes with the path of water flow, causing it to drip out of the water collection tray.

If it is indeed an icing problem, it means it has a low gas pressure problem. Since the gas pressure is dependent on the heat exchange properties of both the indoor fan coil as well as the outdoor condensing coil. Both must be properly cleansed before any attempt to charge up the gas. An overcharged system will KILL your compressor. Please read How reliable is your compressor?

Why is my aircon dripping water so frequently nowadays?

It could be that you requested for “General servicing” only; which clears the choked water pipe, washes the filters and vacuum the fan coil. Nevertheless, the dirt that chokes your drain pipe comes down from the fan coil (accumulating dirt over the years). Vacuum, steam treatment or DIY self cleaning solutions are not effective in removing the dirt from the fan coil. What this means is that after the pipe is cleared, the dirt from the fan coil will soon be washed down and choking the aircon condensate water pipe again.

Things got worst when you burn essential oil, lamp berger, air humidifier or burn incense. They will cause jelly build up which clogs your fan coil and drainpipe as soon as 3-6 months. For more details, please readThings people do to sabotage their air conditioners.1) As mentioned above, general servicing is not effective in removing the dirt from the fan coil. What this means is that after the aircon water pipe is cleared, it will soon wash the dirt from the aircon fan coil will soon down and choking the aircon water pipe again. This problem will be amplified if your water pipe is laid too flat; it is not tolerant to dirt accumulation. 
Thus we have to thoroughly remove the dirt from the fan coil, so that there will be less dirt washing down and clogging it up again.

2) Modern air conditioners bend a part of the aircon fan coil to the back, probably to save space. This is the cross 
sectional view:

cross section of Daikin aircon

This means that condensation is occurring both in front as well as at the back of the air conditioner. Please see a picture taken top down, with the fancoil pivotal shifted left downwards, exposing the back of the fan coil internal water tray. See how choked up it can be:

internal water passage way of Daikin aircon


When this internal water tray is choked, the condensate water doesn’t even have a chance to flow to the main collector tray in front via 2 small openings at both sides of the fancoil. Therefore, no matter how many times you cleared the water pipe, water dripping will still occur. The back coil will get cooler slower than the front coil. Thus, condensation may not be immediate. They usually start to drip after some 30 minutes or more; the technicians would have left by now.

Due to the tight space and gap, it is almost impossible to clear the choke using a vacuum or attempting to wipe it using a cloth. Check how we overcome this problem: click here

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