How to Fix Air Conditioner Leaking Water Outside

How often do you conduct an air conditioner repair? And, have you noticed an ac leak? The most common causes of a conditioner leaking are; a clogged drain line, a broken condensate pump, or a faulty drain line connection. In this article, I highlight all the possible reasons and remedies for an ac leaking water outside.

Is My Air Conditioner Supposed to Leak Water?

Yes, it’s a normal thing for an aircon to leak water. And there exist various factors that determine the amount of condensation you will see on an air conditioner. Notably, the weather dictates how much an air conditioner leaks. If you stay in a humid or sweltering area, your aircon unit may leak condensation during the daytime.

Is Water Leaking from Air Conditioner Dangerous?

Yes and no. Why? Well, it all depends on whether the aircon is dripping water or refrigerant. The water spill can’t harm you. Instead, it will damage your house over time. A coolant is dangerous for humans; the side effects are nausea, headache, and irritation. Furthermore, it’s not environmental-friendly. 

For more information, check if water leaking from air conditioner dangerous?

Dangers of Air Conditioners Leaking Water

An air conditioner can use several refrigerants, but Freon and R22 are the most common refrigerants depending on the age of the unit. The latest aircon models use R410-A – safer than other coolants. No matter the coolant your aircon has, it’s a CFC (chlorofluorocarbon).

Mold and Mildew

If your air conditioner’s drain line causes an overflow in the drip pan, the water could drip into the insulation. The moisture and hot air provide a conducive environment that benefits mold and mildew.

Insulation and Sheetrock Damage

Sheetrock doesn’t hold up sufficiently when wet, and it’s delicate too. If by bad luck, your aircon unit leaks onto the sheetrock, the leak will damage it quickly. 

Electrical Complications 

I’m sure you wouldn’t like water to drip to your aircon unit’s electrical components. But if that happens, a short may damage your air conditioner system.

Health Risks

If your air conditioner’s coolant leaks into the house, it will soon evaporate into a gas harmful to area residents. The gas may lead to several health problems like nausea, asphyxiation, or headaches. 

How and Why Water Forms in Your Air Conditioner

One of your AC’s tasks is to trap humidity in the surroundings. Additionally, its internal blower traps in hot and humid air via the retrieval grille and over the inner cold evaporator coil for cooling purposes. When that happens, it results in condensation around the evaporator coil. I can liken it to water drops on a glass of icy water.

The water around the air conditioner’s evaporator coil flows into a drain pan and later down to the condensate drain. That drain line (PVC pipe) either exits your home or plumbing. The latest ac systems have external and internal units.

How Much Water should Drain from Air Conditioner?

Two primary factors determine the quantity of condensation that your air conditioner produces: the thermostat setting and the outdoor temperature.

Usually, when ac is working, the small pool should dry up effortlessly during a hot day. In an arid environment where relative humidity stays below 50 percent almost every time, the evaporator coil will transport around five gallons of water to the drainpipe every day. In humid environments, the drain pipe can hold up to 20 gallons in a day.

How Do I Know If My Air Conditioner Is Leaking Water? 

A leaking air conditioner means there is a problem stopping its normal cooling cycle. There are clues to look out for if an ac leaks water. So, have you noticed a pool around your closet unit or basement, or is there a mold odor?

If you don’t get rid of the attic water early enough, it can flow to your ceiling, causing a flood which will later drip to your walls when you’re away from home. Thankfully, you can contact an HVAC professional to install extra safety switches to avoid water havoc due to your air conditioner leaking water.

No law states that air conditioners should have these different safety switches, so most HVAC installations don’t include them. The following are typical examples of safety switches:

A pan switch – an HVAC will connect the pan switch to your air conditioner; this shuts off your unit if anything trips it. But, if the HVAC pro installs it improperly, the switch may not work before the air conditioner’s water overflows, causing damages to your home.

For an E-Z trap, the HVAC installs it on the drain line, but it serves the same purpose as the pan switch. The E-Z trap’s tubing enables you to clear any clog forming.

Moreover, if you don’t inspect and remove it early, the water that accumulates in the line forces the float switch to trip, sending a signal to the thermostat. After the thermostat receives the signal, it shuts off the ac system.

Reasons Why Your Air Conditioner Is Leaking Water Outside

Notably, you should know that a tiny pool of water that evaporates fast is likely to be condensation from a routine operation, especially on a humid or heated day. Deep pools of water that persist after the ac unit shuts down are alarming.

The following factors cause an air conditioner to leak water outside but you can also learn how to fix air conditioner leaking water inside.

Clogged or Damaged Condensate Drain Line

An air conditioning unit produces condensation as the cooling process happens; the water vapor condenses to liquid when air temperatures fall. The evaporator coils drop the water to the safety drain pan then out of the house via the condensate line.

Obstacles can crop up within the system’s drainpipe due to debris or clogging of the drain piping along the line. The blocks later cause a pool of water that makes an air conditioner look like it has a water leak outside.

You can clear the condensate drain line at the exit using a dry or a wet vacuum or sticking in a tall wire brush through the opening. If you can’t clear the clogs and restore the drainage system or if you notice a damaged drain line, reach out to an HVAC contractor. Preventing the drain line clogging requires you to flush it with a solution of water and bleach each month.

Crack or Clog in the Drain Pan

Below the evaporator coils, there sits in the drain pan, collecting water runoff during cooling. Typically, water should flow to the condensate drain line. And later outside the house. Cracks and clogs usually stop on the drain, resulting in water spilling out of the damaged drain pan on the internal unit and not the other way round.

Turn off the ac power, and reach out to the condensate drain pan using a wet or dry vacuum to clear up the stagnant water examine each part for clogs or damage. Clear up the debris clogging the coil drain pan.

Moreover, clean the drip pan to get rid of any algae growth. It would be best if you replace damaged or cracked drain pans to prevent the leaking water from damaging your cooling system and your home.

Frozen Evaporator Coils

The AC’s evaporator coils freeze for different reasons. One is poor airflow due to dirty air filters, and the other is when the air conditioners leak refrigerant, which prevents heat absorption. The ac air conditioner’s frozen evaporator coils melt, leading to excess water runoff that flushes to the condensate drain line, leaking the conditioner.

When evaporator coils freeze, shut down the cooling unit of the air conditioner leaking water and turn on its blower at the thermostat for circulation of warm air over the air conditioner’s filter and coils. Also, check if there are dirty air filters, and replace them if need be. If you can’t locate them, book an aircon appointment.

The Unit was Improperly Installed

Some errors typically happen when an air conditioning contractor installs a new outdoor air conditioning unit. Water leaks because of incorrect sizing or secondary drain pan during the installation process. A newly installed air conditioning system fails many times because of an aircon contractor or faulty air vents.

According to EPA’s findings, about half of the total aircon systems in the US don’t perform as noted in their advertisements because of improper installation. Your aircon can stall in a storm of system failures that require expensive repairs.

The Temperature is Below Operational Levels

Leaking air conditioners could also result from chilled air below 55 degrees outside. The evaporator coils can cause a chilled metal surface on the home’s drain system or condensate flows. I advise you to shut off the ac if you notice water leaking through the pipe outlet.

Refrigerant Leak

An air conditioning leaking water can happen in two ways; a refrigerant leak or a water leak. When refrigerant levels go down below a particular level, it causes a decrease in pressure of an air conditioning system, leading to a build-up of ice in the evaporator coils over time. Moreover, there will be an overflow of water in the drip pan. If the drain pans can’t hold anymore, they force the excess water through the drain pan opening.

Problems with the AC Seals

Each air conditioning system has a seal that prevents a build-up of warm air in your unit. But if not fitted correctly, or someone has compromised it, hot air enters the unit. Also, when warm air blows the cold air in the ac unit, it condenses water on the condensate line. The only solution is to conduct an air conditioning repair, something a professional can help you do.

Dirty Air Filter

The air passing through the air conditioning system can make the air filters dirty with grime; this can block airflow on the evaporator coils. Moreover, it causes ice buildup causing excess water in the primary drain pan. When water subdues the primary drain pan, it causes water to leak through the central ac unit.

How to Fix Air Conditioner Leaking Water Outside

The following DIY steps will help you rectify your AC leak problem:

1. Shut down the ac – Immediately after you notice your ac leaking, turn it off until you find and address the problem. If the evaporator has frozen, let it melt while waiting for an HVAC technician to work on it.

2. Check for ice – if you check and find an ice buildup on the lines of your outdoor ac system, then you need freon. After that, in the air handler, check if there’s an ice buildup on the evaporator coils.

3. Handle water leaks – use a wet or dry vacuum to squeeze out the water stuck in the drain pan. Later, use fans to clear the areas with algae growth.

4. Replace the air filters – check if the HVAC pro installed the air filters property and if they are dirty. Technicians advise ac owners to change their system’s filters every 90 days.

5. Clean the dirty condensate drain line – the condensate drain line traps condensation, dust, and debris. If the ac leaks, check and clean the drain pan.

6. Turn off the aircon when it’s cold – if the aircon system is on during temperatures below 60 degrees, it will freeze. So, when it’s cold, look for alternative ways of boosting comfort levels in your home.

7. Contact an HVAC technician – if the DIYs mentioned above don’t work, contact an HVAC pro who can tune up your ac system or add some refrigerant.

How to Clean AC Condensate Drain Line

1. Turn off your aircon

2. Look for a white, black, or grey PVC pipe and follow it to where it drains water (drain line). The drain line attaches to the wall, closer to the condenser unit.

3. After locating the drain line, look for the opening. It usually has a cover and T-shaped tees. Uncover it to see if there’s any blockage. Remember to use protective gloves.

4. Pour white vinegar through the drain line to clear out buildup. After that, leave for more than 30 minutes or longer for better results.

5. Flush the pipe using water and after rinsing, check if there is some trace of clogs. Repeat this after one to three months.

Can We Use AC when Water is Leaking?

You have to know the cause of the air con’s leak to gauge if you should use it. If it’s a refrigerant leak, shut down the ac to prevent damage. If an ac leaks due to frozen evaporator coils, don’t turn it on unless you fix the issue. Otherwise, you’re setting up your ac for avoidable damages.

Additionally, if the leak is due to dirt buildup or blockage, you can continue using the ac. But remember, you have to clear the blockage soon.

For more information on this subject, check if you can use AC when water is leaking.


One of the simplest ways of fixing an air conditioner leaking water is by cleaning the condensate line using vinegar. Because in a few minutes, your ac will be up and running unless the problem is severe.

So, if your ac unit isn’t pulling heat or can’t create chilled air, should you do a DIY or call an HVAC pro?