Aircon Dripping and Leaking? Learn Why and How to Fix

Due to its tropical climate, Singapore has a high demand for air conditioning units. Temperatures run high throughout the day and night. The high humidity environment doesn’t make things any easier on the average homeowner either.

Therefore, proper cooling is required in any home that can afford it. How high or low you set your aircon unit will vary greatly. There are no guidelines for personal cooling comfort. But what’s certain is that aircon units malfunction more often in a country like Singapore.

Why? Because they’re much more affected by the climate. This can lead to people having to pay serious money for repairs and being unable to perform their day-to-day activities. As you’ll soon find out, a lot of this can be prevented with good judgement and proper maintenance.

Yet, it’s still good to know exactly what may cause your aircon unit to drip or leak. As well as a few tips on how to fix it, whenever possible.

Climate Impact on Air Conditioning Units

In many tropical countries, dust is very hard to deal with. As Singapore gets particularly hot, many aircon units don’t work properly. Very hot weather invites excess skin shedding and most dust inside households is made of dead skin flakes.

As mentioned above, Singapore doesn’t just get hot, it’s also very humid. While most aircon units are designed to effectively remove moisture, huge spikes in humidity can overwhelm them. This leads to improper cooling, temperatures rising inside your home, and excess water spilling from the aircon unit itself.

Top Causes for Leaks, Drips, and Spillage

Defective Condensation Pump

One of the leading reasons for leaky air conditioning units is a defective condensation pump. This component is typically located right under the cooling coil. Its primary objective is that of preventing leaks by draining the water.

A defective pump may cause water to drip because it can’t properly drain it. At the same time, too much dust accumulation may also cause the pump to malfunction. This too leads to water leaking from the air conditioning unit.

Clogged Condensation Line

The condensation line is the component responsible for eliminating the condensation forming inside your aircon unit. It can be made of both metal or PVC, yet plastic tends to be the preferred material.

Whenever your air conditioner cools the warm air sucked from inside your home, it creates moisture vapors. That’s because warm air runs over frozen, or cool refrigerant pipes.

When this happens, vapours turn into a liquid that needs a proper collection and draining system. A clogged line prevents the excess water from being drained from the aircon. Therefore, once the collection system overflows, you may notice your aircon dripping.

Blocked or Dirty Air Filter

The aircon unit’s air filter is responsible for maintaining proper airflow through the unit. Without good airflow, the air inside the unit can freeze. This leads to the formation of ice particles.

That ice melts whenever the aircon unit turns off and the temperature slowly rises. It happens whether you turn it off manually or once the unit detects the pre-set air temperature and stops automatically.

Melting ice particles then start dripping. If the situation is bad it can even lead to a leak. This is one of the leading factors that cause malfunctions in an air conditioner unit. And, another factor that’s heavily influenced by the amount of dust in your home.

Note that a blocked aircon filter isn’t the only thing that can go wrong. Sometimes it’s enough for the filter to be partially obstructed. In many situations this is sufficient for the formation of ice particles when the coil temperature drops too much.

Then the same thing happens as with a blocked air filter. The accumulated ice melts once the unit is switched off and the drip tray often overflows. It just happens slower than it would when the filter is completely clogged.

Leaky Coil

Unfortunately, coils don’t last forever. Some of them may come faulty straight from the production line. Either way, it’s another component of your air conditioning unit that may cause the system to leak or drip water.

One of the reasons why coils may leak is because the condenser coil is usually located outside your home. As long as your aircon was installed properly. Being outside exposes the coil to environmental factors as well as more dirt and other debris.

Accumulation of dirt causes a blockage which, in turn, causes the coil to leak. Many Singapore homeowners have to deal with this due to the climate and how it favours excess dust formation.

Clogged Drain Line

Here’s another component of your aircon unit that’s susceptible to clogging. The drain line. It’s an essential component that facilitates draining the excess water out of the aircon unit, at a steady flow rate.

A malfunctioning or clogged drain line drains water much slower. This leads to serious spillage inside the aircon unit. The tropical nature of Singapore already favours excess dust and debris formation around air conditioners.

However, that’s not the sole reason why drain lines clog. Other factors include formation of mould and various fungi. This happens because of the high humidity ecosystem created by the aircon unit. And because of the various bacteria and debris that help fuel the growth of mould and fungi. This is yet another reason why in some climates regular maintenance of the aircon unit is essential for optimal performance.

Bad Installation

How do you know if your aircon unit wasn’t properly installed if you yourself have no knowledge on the matter? One way to check is comparing the front section of the unit with the rear section.

Following a proper installation, the aircon should be cooler in the front than in the back. This creates the right air flow and temperature inside to avoid freezing and ice melting.

Another reason why your aircon is leaking, that’s due to installation, is the wrong inclination. Improperly inclined aircon units may not be able to efficiently drain the water. This leads to excess water accumulation and spillage.

Rust Formation

Whenever water, air, and metal meet there’s a possibility of rusting. In the case of aircon units, drain pans can often rust. A poorly designed metal drain pan rusts more easily than you think. Especially one that doesn’t drain properly to begin with.

What persistent rusting does is cause clogging and obstructing the water flow through the drain line. Inconsistent water flow, as previously explained, causes the spillage of the drip tray which leads to dripping or serious leaks over time.

Frozen Evaporator Coil

A frozen coil is often a direct effect of a broken or clogged air filter. One of the main objectives of the aircon’s air filter is regulating air flow over the evaporator coil that sits inside the aircon unit.

So, what does an obstructed air filter do? It prevents warm current from passing, which in turn causes the internal temperature to drop. A serious drop in temperature leads to the evaporator coil actually freezing and causes the formation of ice crystals.

The crystals then melt and drip an excess amount of water into the drain/drip pan, which leads to spills and water leaking from the aircon unit.

Improper Maintenance

Improper maintenance or lack thereof is another leading cause of leaking aircon units. However, this should be a given by now. As you can see, many of the main causes of drips and leaks relate to how clean the aircon unit is.

Due to dust being much more present and having a massive impact on the unit’s functionality in Singapore, you need to clean the unit more often. And this doesn’t extend just to the air filter.

Make sure you open up the unit and check for dust, mould, and fungi inside it. Empty the drip tray on a regular basis, maybe even every two or three days. Depending of course on how often you use the aircon and how low you set it.

Cold Temperatures

Cold outside temperatures may also cause the aircon to freeze. However, this isn’t a leading issue in Singapore. Not even night-time averages drop below 68 degrees.

For the aircon unit to freeze, outside temperatures should drop well below 60 degrees, which is a very rare occurrence in a tropical climate.

How to Clean and Service Your Aircon Unit

Here are some tips on how to service your aircon unit to avoid most of the problems mentioned above. Some of these methods should be listed in most manuals, but we all know that not everyone can be bothered to scan the manual for information.

1.      Cleaning the Coils

As already mentioned, your aircon unit has both exterior and interior coils. The exterior coils make up the condenser coil and the interior coils are made of the evaporator coils and fan coils. All of them need proper maintenance to prevent freezing and clogging.

Exterior Coils

First, you’ll want to power off and unplug your aircon unit. Use a screwdriver to unscrew the outer casing in order to access the condenser coils. Check the manual or take a picture at this point. That’s so you’ll know where everything goes.

It’s best to remove some additional components that get in the way of you doing a proper cleaning. Use a soft brush to clean the coils for any grease, dirt, and other debris. Use a specialised cleanser for aircon coils. Order one online or buy it from the local hardware store.

Don’t forget to rinse the coils with water when done. Make sure to wipe the coils dry before putting everything back. Don’t let them air dry as that only invites excess dust inside.

Evaporator Coil

Once again, you’ll want to power off your unit and unplug it for safety reasons. Remove the front cover of the aircon unit as instructed in the manual. Most aircon unit covers are intuitive but it never hurts to double check.

You can use a soft brush on the coils or a small hand vacuum machine. For an even more thorough job, you can use a can of compressed air spray while catching the dust with the vacuum machine.

While a brush will do a good job too, note that evaporator coils have thin aluminium fins. They’re much more susceptible to bending if you apply pressure with the brush. There’s no need for any cleaning solution here. A dry scrubbing should do the trick.


This part is a bit trickier. It requires a specialised cleaning solution. It also requires you to remove the inside chassis of the unit in order to access the fan. Again, consult the manual or take a picture of how everything looks and where every component goes before proceeding.

Most fan cleaning solutions are spray-on. You should leave the formula on for the indicated amount of time to ensure that it dissolves everything. Rinse with warm water. After all the solution and water drains off, rise the fan again. It needs that extra thoroughness.

Completely dry the fan before putting everything back together.

2.      Cleaning the Condensate Drain

Safety first. Turn off your aircon unit and unplug it. Use gloves when working to protect yourself as well as the condensate drain, mainly the aluminium fins.

Use a very soft brush attachment on a handheld vacuum unit or your regular vacuum machine. Use either a water hose or a spray bottle to wash off any loose debris. Use a recommended coil cleaner and let it foam for the recommended amount of time.

Most products require a minimum of 10 minutes for the foam to bond with the dirt particles. But 15 minutes should be more than enough.

Rinse the coil again with water. In most parts of the world, this is something that should be done twice a year, in the spring and in the summer. You may want to do this three to four times if you live in Singapore to avoid any issues.

You’ll also want to pour a distilled vinegar solution down the drain pipes to thoroughly clean the insides. Let it sit for 30 minutes or one hour as it should be enough to take care of hard grime deposits and some of the rust. Flush the drain pipe with clean water for a few minutes to remove the vinegar solution and any residual debris.

Extra Tip

Always ensure that whenever you open your aircon unit, whether inside your home or outside, the first thing you do is check all drip trays and empty them. Inspect them for rust and use an appropriate solution to remove any debris, before moving on to cleaning the larger components of the aircon.

Professional Aircon Servicing and Repair

No matter how well you care for your air conditioner, there are still many things that can go wrong with it. The harsh climate alone takes its toll. Some components may not be as long-lasting as advertised and others could be poorly constructed. Either way, always set some money aside in case you need professional assistance.

When to Call a Professional

There are three main reasons to call a professional to inspect and service your aircon unit:

  • You lack the tools, knowledge, and products to service it yourself.
  • You don’t have a manual for your unit and you’re afraid to mess something up.
  • You keep your aircon unit in pristine condition, clean it regularly, and it still drips or leaks.

Due to the high demand for home air conditioning units in Singapore, there are plenty of professional services that you can find online. Ask for a quote and explain your problem thoroughly before asking for assistance.

Also, don’t be afraid to skip the research and ask someone you know for a professional contact. Online testimonials aren’t always what they appear to be. And if word of mouth can save you some time, why not try that as well.

Some Side Effects of Malfunctioning Aircon Units

Let’s get the obvious one out of the way – excess heat and the inability to feel comfortable and go about your day.

Aside from that, there are other things that can be affected by a broken or ill-performing aircon unit. Not all air conditioners drip from the same spot. Therefore, it’s possible that you have a leak or some dripping behind the unit. One that you can’t see or feel.

This is very dangerous as it invites the formation of mould and fungi on the wall. All of which can be detrimental to your health and also lead to structural damage of the wall.

Another problem with a leaky unit is financial. If you can’t repair a unit on your own, you may have to call a professional. Repairs costs vary wildly depending on what components need replacing. Also note that in some situations, a unit that’s been dripping for years may be beyond repair.

In that case, you either patch it up on a regular basis or buy a new one. Neither option is great. Additional patch work slowly eats away at your budget and an aircon unit that doesn’t work well tends to draw more power too. Buying an entirely new unit may be too big of an investment for some homeowners.

Take Care of Your Aircon to Ensure Your Personal Cooling Comfort

It’s always best to service your air conditioner on a regular basis instead of waiting to see if it leaks. The tips in this article should help you understand what’s wrong with it. But don’t forget that many of the situations presented above can be avoided.

If not for that, understand that patching up your aircon too often leads to unfixable damage and you may find yourself in need of a complete unit replacement. When in doubt, always consult a professional, preferably early on, before making too many attempts to fix it yourself.

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