Leaking aircon with water stains

The air conditioner (or aircon) is an essential appliance in countless homes across Singapore, especially due to the perpetually warm and humid weather we experience. With an aircon, we get to enjoy cool, crisp air that keeps us feeling fresh and comfortable.

However, one of the problems that often surface with the use of this appliance is dripping water or water leaks. To help you better understand the cause of this issue, we’ve listed some common reasons for a leaking aircon. We’ve also included some solutions and prevention tips so you won’t have to worry about water stains!

Causes of a leaking aircon

Causes of a leaking aircon (infographic)

Faulty or damaged parts

• Broken condensate pump

The condensate pump is a component within the aircon that helps to discharge water into the condensate drain pan. It can be found below the cooling coil.

When the pump is functioning well, it helps to prevent leaks. However, when it’s broken or malfunctioning, water may overflow and start to drip from the aircon.


• Rusted drain pan

The purpose of a drain pan is to collect water that drips from the evaporator coil. 

Due to the presence of air and moisture, drain pans that are made from metal can rust. This rust can subsequently eat away at the metal, causing holes and gaps to form and water to leak from the drain pan.

Low refrigerant levels

The refrigerant is an important part of the aircon system as it helps to absorb heat and cool down the air. If refrigerant levels are low, ice can form around the evaporator coil. When this ice melts, water begins to leak from the aircon.

If you notice a bubbling or hissing noise coming from the appliance, it could be a sign that the refrigerant is leaking from the aircon. Immediate assistance from a professional will be required to fix this issue.

Higher water levels

Frozen evaporator coils

Evaporator coils are metal wires found in the interior of an aircon unit. When dust builds up on the coils or refrigerant levels run low, ice can form. This results in water levels beyond the system’s capacity, leading to water leakages.


Leakage of air

In the case of a properly functioning aircon, warm air that enters the appliance should pass through the vent. However, in certain cases, this warm air may fail to do so and this is known as an air leak. The result is condensation on the refrigerant coils and subsequently water leaks.


Low external temperatures

When the temperature surrounding the aircon becomes too cold (below 15.5°C), its interior coils may freeze. Once the ice melts, water will drip from the appliance. Furthermore, the lubricating fluid found within the aircon will become thick and lead to a unit malfunction.

Due to the high temperatures in Singapore all year round, this is unlikely to be a cause for concern.

Installation issues

Man in plaid shirt installing an aircon

If you notice water leaking or dripping from the aircon despite the fact that it is new, improper installation could be the cause.

An aircon unit that’s placed on a tilted surface could result in water leaks. Additionally, if the unit is not sealed properly, warm air from the environment will come into contact with cool air from the condenser. This leads to condensation and water dripping from the aircon.

Irregular cleaning and maintenance

The buildup of dirt and dust can cause water to leak from an aircon. Thus, regular cleaning and maintenance are important for the proper functioning of your appliance.


Clogged air filters

Dirty aircon filters on top of dismantled aircon unit

Air filters that are clogged by dirt and dust make it difficult for air to pass through to the evaporator coils. When this occurs, the coils turn icy. 

When the aircon is switched off and temperatures within the appliance rise, the ice melts and results in excess water that overflows out of the drain pan.


Clogged drain line

The accumulation of dust and debris in the drain line can cause clogging to occur. As water is unable to escape from the aircon quickly enough, the drain pan overflows and water drips from the appliance.


Clogged condenser unit

The condenser coil is one of the main parts of a condenser unit, which is found outside your home. When dirt, dust and debris accumulate within the unit, it experiences blockage and the condenser coil becomes more susceptible to leaks.

How to fix a leaking aircon

The right method to fix a leaking aircon depends on the cause. While cleaning of the various appliance parts is possible without the help of a professional, other causes such as the leakage of air and broken condensate pumps require the help of an expert.

Need help fixing your leaking aircon?

Our professional team can help to identify the issue with your appliance and fix it promptly!

Read on to find out how to clean the different parts of the aircon!

Clean the filters

Cleaning the filters is often the easiest and fastest as compared to other parts of the aircon.

  • Step 1: Remove the filters
  • Step 2: Vacuum on low power to remove any dirt and dust or wash the filters with lukewarm water
  • Step 3: Leave the filters to dry before fixing them back


Clean the condensate drain pan and drain line

As the buildup of rust can be detrimental to the integrity of the drain pan, it’s important to check and clean the pan regularly. You can use rust removal products or natural chemicals like vinegar to remove traces of rust.

Additionally, ensuring that the drain line is clear of dirt and debris will allow water to flow out of the aircon smoothly and prevent choking.

  • Step 1: Locate the drain line and the access point
  • Step 2: Pour some distilled vinegar down the drain line
  • Step 3: Leave it to sit for 30 minutes
  • Step 4: Rinse the drain line with water


Clean the evaporator coil

Evaporator coil in an aircon

When a layer of dust accumulates on the evaporator coils, air is unable to come into contact with the coils, causing ice to form. Hence, proper cleaning will help to resolve this issue.

  • Step 1: Spray the coil with some aircon cleaner or a mixture of detergent and warm water
  • Step 2: Leave the solution to work its magic for a few minutes
  • Step 3: Wipe the solution off with a cloth


Clean the condenser coil

Cleaning the condenser coil of dirt and debris and removing any blockage will ensure the proper functioning of the condenser unit.

  • Step 1: Remove dirt, dust and grime with a soft-bristle brush and an aircon cleaner
  • Step 2: Rinse the coils with warm water

How to prevent the aircon from leaking

Regular cleaning

Removing filter from aircon

Cleaning your aircon regularly will prevent any dirt or debris from accumulating in the appliance. This includes cleaning the filters, condensate drain pan and coils. If you have a busy schedule or simply find it a hassle, contact a professional company to assist you with the task!


Regular inspection

Scheduling for regular inspections of the aircon unit is helpful in identifying potential problems before they occur. Additionally, if problems are already present, they can be rectified before they become more serious.

Keen to schedule an inspection or need aircon servicing?

At Fixwerks, our team of engineers are equipped with the knowledge and experience needed to inspect and service your aircon efficiently and effectively.

Frequently asked questions

Is a leaking aircon dangerous?

While water leaking or dripping from the aircon can damage your home and walls, it isn’t dangerous. On the other hand, a refrigerant leak can be dangerous and should be addressed immediately.


Can I still use my aircon even while it’s leaking?

You aren’t recommended to continue using your aircon while it’s leaking as it could damage the appliance. Instead, get in touch with a professional repair company to assist you with the leak as soon as possible.