Why Does My Air Con Leak Water? Is It Normal?

Why does air con leak water

Water coming from your air conditioner sounds like a bad thing, but did you know that’s not always the case? Depending on the type of air conditioner you have, it’s normal for some condensation to come from the outdoor unit or drain pipe. 

Which begs the overall question: when is a water leak normal for my air conditioner? 

A reverse cycle air conditioner extracts moisture from the air to heat or cool, so some water coming from the correct place – like the drain pipe – is part of its normal function. However, if water is leaking or dripping from your indoor unit, or water is coming through the roof, it’s a sign that your AC unit has a fault. 

In this article, we have explained each of the reasons your air conditioning unit is leaking water in further detail. Many of these reasons when left alone can stop your air conditioner from working, so we have provided you with some tips so you can resolve the issue and get back to enjoying air conditioned air. 

Read on to learn all about leaky air con units. 

Is It Normal for an Air Conditioner to Leak Water? 

It can be normal for air conditioners to drain condensation from the outdoor unit or condensate drain line. However, it’s not normal for air conditioners to leak excessive water or leak from the indoor unit. 

Why do air conditioners generate condensation? Ducted or split system air conditioners use heat pump technology to change temperature, and this pulls moisture out of the air. Since air conditioners aren’t connected to any plumbing or water source, any water coming from your unit is what it extracts from the air. 

When your air conditioning system is cooling properly, the condensation collects in the drain pan and flows through the drain pipe outdoors. That’s why you may see water dripping from the drainage tube, especially when your air conditioner is working hard. In fact, if your air conditioner stops draining any moisture, this can indicate a problem such as a drain line blockage.

When a reverse cycle air conditioner is heating, you’ll usually see moisture drained directly from the outdoor unit instead. This is also part of the normal function of the air con unit. 

Evaporative air conditioners can also release water as part of their normal function, especially at the end of a cooling cycle. Your owner’s manual or air con technician can let you know if and when your evaporative air conditioner should release water. 

If you see water dripping from your indoor AC unit, it’s a sign your air conditioner has a problem. When your air conditioner was installed, the technician would have installed a drainage system to safely remove any condensation outdoors. Indoor leaks indicate problems such as damage or clogging in your drainage system. 

If you’re only seeing a small amount of water coming from your condensate drain pipe, the good news is that this is normal and does not affect its operation. You should still keep an eye out for where it’s draining, though – ongoing condensate drainage in the wrong spot, such as a concrete pathway, can lead to mould and slippery algae growth. 

It’s also a good idea to investigate if you see your air conditioning system is generating a lot more condensation than usual. This can suggest it’s overworking, and if the problem isn’t resolved, you may end up with an indoor leak once the drain pan rusts or overflows. 

Having a problem with excess water leaking from your air conditioning? Keep reading to find out why this happens and how to fix it. 

What Causes an Air Conditioner to Leak Water? 

There are many causes for your air conditioner to leak water. It’s important to identify what the issue is before further damage is caused to the unit or to your health. 

Below we’ve identified some of the most common reasons that water leaks from air conditioning units.

1. Damage to the Condensation Pump 

A condensate pump is a small pump that transports water from a central collection point to a remote area such as a floor drain or a utility sink. The condensate pump is an important part of your air conditioning system and collects the water that has built up in the unit. 

These pumps can stop working due to normal wear and tear. It generally stops working when debris or algae build up and clog the pump. You can fix it by switching it off and cleaning it with warm water and dishwashing liquid. If that doesn’t work then it may need to be replaced. 

2. The Age of the Unit 

If your air conditioner is old, wear and tear is likely to play a part and be the main reason that it is leaking water. The most common reason that an older AC unit leaks water is that the drain line is blocked.

If that’s the case, then the water has nowhere to go and that causes the aircon unit to leak water. It may also leak water because it has a damaged or rusted drain pan, so the water leaks out. 

If you have an aircon refrigerant leak, low refrigerant gas levels can mean that the coils freeze up when the unit is running, and then the ice melts off when it is turned off. The condenser pump may also be broken. 

All of these reasons are linked to the age of the unit, so it pays to get it serviced regularly to avoid water leaks. Getting your air conditioner serviced regularly gives you the opportunity to have these important components replaced before they become an issue. 

3. Low Refrigerant Levels 

Maintaining the refrigerant levels in your air conditioner is important. This is critical to soaking up heat in the environment, and assists with cooling the air conditioning unit’s components such as the evaporators or compressors. 

The refrigerant absorbs the heat from the indoor air and then transforms it from a low-pressure gas to a high-pressure liquid. The refrigerant is then sent to the exterior, where a fan blows hot air over the coils before releasing it outdoors. After doing so, a separate fan inside the house blows over the cool coils and the result is cool air. 

If the refrigerant levels are low it can affect the unit’s ability to do these things. This issue can be resolved by getting a technician to come and repair the leak, then regas your AC unit. 

4. Damaged Drain Pan 

A damaged drain pan is one of the most common reasons that an AC unit leaks water. It’s normal for the drain pan to have water, but water should flow easily, not settle or build up inside the drain pan.

If you have a portable air conditioning unit then you may need to empty the pan manually. The drain pan can also become damaged and ineffective if humidity is too low. That leads to lower condensation. 

If, however, the drain pan is cracked and has a leak, it will need to be repaired. Minor cracks can be fixed with epoxy glue as a plug to stop the leak. In other situations, you’ll need to replace the entire drain pan – which is much better than replacing the entire AC system. 

5. Clogged Drain Lines 

Another reason your air conditioner is leaking water is that the drain lines have become clogged with dust and dirt. This is easily fixed by turning the AC off and then inspecting the unit’s tubes for leaks, cracks or other issues. If damaged, the drain lines will need to be replaced. 

If the problem is a blockage, first remove any water that’s collected inside the drain pan. After you’ve removed the water, you can use a wire brush to unclog it. Ensure the drain line is flushed to remove any debris and contaminants. Make sure that the PVC cap is put back on properly and test the air conditioner to see if the issue has resolved itself. 

6. Poor Installation 

It’s entirely possible that your air conditioner is leaking water because of poor installation. When the unit was installed the technician may have made a mistake – for example, they might have placed the drain pipe at a higher elevation than the main air conditioning unit. 

The result is that excess water flows back into the main unit and causes a leak. To resolve the issue you’ll need to get the air conditioning unit re-installed by a more experienced professional. 

7. Clogged Air Filters 

Clogged air filters are the most common cause of air conditioning leaks. If the filters become clogged with dust and debris, then the air filter has restricted air flow, which in turn forces the unit to use more energy to cool or heat your home. If the air filters are clogged, the unit can overheat and the limit switch may fail. 

A clog can also lead to frozen evaporator coils, which reduces the unit’s ability to remove heat from the air, and your entire unit may break down. You can resolve the issue by turning off the unit and removing the filter before vacuuming it. Then wash the filter and reinstall it. After you’ve reinstalled the filter, check if the issue has been resolved. 

8. Infrequent Maintenance 

It’s really important to get your air conditioner maintained regularly. Regular maintenance ensures that you will be able to identify if there are issues such as clogged air filters or a damaged drain pan. They can then be fixed before a bigger issue develops. 

You should get your air conditioner serviced at least once or twice a year to ensure that it lasts the average life of an AC unit, which is approximately 10 to 15 years.

9. Outdoor Humidity 

Air conditioners are affected by the humidity. If the humidity is high, then that will cause a build up of condensation around the condenser coils. That causes a build up of water. 

Although the coils are designed to remove heat from the air, if they don’t have sufficient coiling then the condensation won’t evaporate. Instead, moisture will build up on the coils which will lead to the unit dripping water. You can prevent this from happening by checking that the coils are clean and that the unit has adequate ventilation. 

10. Frozen, Dirty or Damaged Coils 

The coils are an important component of your air conditioner, but they can become frozen if there are problems with your unit. If you think that they might be frozen then open the air handler and look to see if any ice has accumulated around the outdoor refrigerant line. 

If the evaporator coils are dirty, extra pressure will be put on the AC unit, which increases the risk that the coil will freeze. A frozen coil can’t absorb heat as efficiently. If your air conditioner is making noises like buzzing or humming, it could be a sign the coils are frozen or dirty.

The best way to resolve the issue is to get a technician out once or twice a year to inspect your unit and address any small issues such as frozen, dirty or damaged coils. The technician will then clean or replace the coils for you. 

How Can I Prevent My Air Conditioner From Leaking Water? 

You can prevent your air conditioner leaking water with regular maintenance. Not only does this keep your air conditioner clean – ensuring it isn’t overworking and overproducing condensation – it also helps prevent breakdowns.

Ensuring you regularly clean your unit and the air filter within it regularly can also help prevent leaks. 

It is best to get your air conditioner serviced  by a professional once or twice a year so that any little issues can be identified before they become bigger issues. For that reason, you should also contact a professional for diagnosis and repair if your air con unit is having problems. Putting it off can cause the problem to escalate, leading to more damaging water leaks. 

The final way to prevent air conditioner leaks is to ensure your system is installed by an experienced professional. Poor installation is a leading cause of leaky air conditioners, especially if the drainage system isn’t up to scratch. 

By choosing a knowledgeable and well-reviewed air con service for both installation and maintenance, you have the best chance of keeping your air conditioning system functioning properly. 

Leaking Air Conditioner FAQs 

Is Water Leaking From My Air Conditioner Dangerous?

If water is safely draining from the condensate drainage system as intended, this isn’t anything to worry about. However, if water is dripping from your air con’s indoor unit or any other place it shouldn’t be, this is a sign your air conditioning system has a fault. 

A leaky air conditioner can be dangerous as it can lead to further water damage to your home, attract mould or termites, and could even make you sick. It’s also bad for the health and lifespan of your air conditioner if the problem isn’t addressed. A leaking air conditioner that isn’t repaired will have a shorter life expectancy, performance will continue to reduce, and it will soon need more costly repairs or a full replacement. 

For that reason, you should always speak to an air conditioning technician if your system is leaking water. 

Should I Turn My Air Conditioner off if It’s Leaking Water? 

If your air conditioner is leaking water from the indoor unit, then you should turn it off immediately and contact a professional service technician. 

If your air conditioner continues to run then it is at an increased risk of becoming damaged, as well as causing water damage to your home. 

Can I Use My Air Conditioner if It’s Leaking Water? 

You shouldn’t use your air conditioner if it’s leaking water from the indoor unit, as it can damage your unit and home over time. Water leaks can create water damage in your home and can promote mould growth. 

To avoid damage to your home or contents, stop using your air conditioner if it’s leaking and call a technician for an inspection. However, if it’s simply draining water from the condensate pipe, it’s safe to keep using your air conditioner. 

What Should I Do if My Air Conditioner Is Leaking? 

The first thing you should do if your air conditioner is leaking water indoors is switch it off. After you’ve switched it off, you should call a professional to inspect the unit. 

An AC technician has the knowledge to identify the issue and a quick repair will save you money in the long run, rather than continuing to use the unit in its current state.

However, if you have small amounts of water coming from your drainage system or outdoor unit, this can be perfectly normal. If you’re worried, though, you can speak to an air conditioning technician during your next service to confirm if it’s normal. 

Related Questions 

How Do You Know if Your Air Conditioner Drain Line Is Clogged? 

Signs of an clogged air conditioner drain line include:

  • A musty or mouldy smell near the indoor unit or in the vents 
  • Water leaking near the unit
  • Visible water damage
  • Air conditioner isn’t cooling properly
  • Air con switches itself off or doesn’t turn on 

Can a Leaky Air Conditioner Make You Sick? 

A leaky air conditioner can make you sick through poor indoor air quality and mould growth. Symptoms of this include flu-like or allergy-like symptoms, such as coughing, headaches, watery or dry eyes, sneezing, and fatigue. 

Over time, the symptoms may become more serious and can include asthma, allergic rhinitis or pneumonitis. For that reason, it’s important to have any air conditioner problems – like water leaks and musty smells – addressed as soon as possible. This ensures the indoor air quality in your home remains healthy. 


This article is published in good faith and for general informational purposes only. It does not constitute an estimate or quote for any specific service. Platinum Power & Air does not make any warranties about the ongoing completeness, reliability and accuracy of this information. This article is not intended to replace consultation with a licensed technician. 

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