How To Solve Water Dripping From Split AC Indoor Unit

Your home dripping water isn’t a fantastic scene. It’s devastating. But, how do you deal with an ac unit leaking water? Well, that’s the motive behind this article. You will know what causes a split ac to leak water and remedies for that problem. Without a blink, let’s get into it!

Is it Normal for AC to Leak Water?

It’s natural to see an ac leaking water since the manufacturers made it to generate condensation while operating. You don’t have to worry if you notice a tiny puddle of moisture on the condenser unit that dries up fast when it’s hot. It’s normal to see an ac leaking water while running. However, if the leak from the condensate tray is persistent, call an HVAC pro to check the split ac for issues.

Water Leaking from Split AC Outdoor Unit

It’s natural to see a tiny water puddle underneath your split AC’s outdoor unit. Such condensation happens in highly humid or hot weather since it runs harder during such conditions. For now, I would advise you to watch your ac with a keen eye. The condensation levels depend on:

  • Thermostat settings
  • Outdoor temperatures

If you arrive at home to find a tiny condensation puddle near the AC’s drainpipe, don’t panic, it’s a norm for air conditioners running extra hard — specifically on humid or hot days. Likewise, the small condensation puddle is underneath your split ac unit; it has probably come up due to regular operation.

Water Dripping from Split AC Indoor Unit

Your air-con soaks up humidity available in the air. Moreover, the moisture gathers in the AC’s drip pan, and then later, it drains out via the drain line. If you incorrectly installed the drain line or disconnected it, there will be an overflow from the drip pan, causing an ac leak within your home.

You fix the drain line issue; it’s easy! You only have to ensure you correctly connect the drainpipe to the AC’s drip pan. If water leaks persistently, replace the drain line.

What Causes Water to Leak from Split AC Unit

Bad Air Conditioner Installation

A newly installed ac is leaking water. What a surprise, right? Well, not really because a new split ac system is bound to leak water. That is if the HVAC technician installed the ac unit incorrectly.

For example, when your air conditioning unit and drain pipes aren’t balanced, it obstructs water flow in the drain pipe. And for that obstruction, your split system air conditioner begins dripping water.

Similarly, when your central air conditioner isn’t level, it leaks water inside your house. The same happens when you install the window AC completely flat.

Clogged Drain Line

An obstructed condensate drain line is the most prevalent cause of your ac unit oozing water. The water gathered by the ac unit during dehumidification contains debris and dust. So, over time, if you fail to clear up the condensate drain line, the debris and dust will accumulate, causing a blockage.

Finally, water will begin to collect in the air conditioning unit, resulting in a spill from the drain pan inside your home. Some modern air handlers have a feature in the form of a “cutoff switch” that turns off the air conditioning unit in case of a blockage within the condensate line.

A cut-off switch is a fantastic option to save your home from damage caused by water. However, if your air conditioning unit doesn’t have the mentioned feature, you’ll have to take preventive measures yourself.

Rusted or Cracked Drain Pan

A drain pan sits underneath the air handler or evaporator coils in an air conditioner. The drain pan catches condensation when it’s dropping. From there, water flows from the drain line and outside the house.

Now, if anything damages or rusts the drain pan, the excess water will leak instead of moving to the drain line. When an air conditioning system has hit the 15+ age mark, it starts to show symptoms of old age.

Moreover, a drain pan that has rust all over it is a common occurrence. A drain pan rusts or erodes over time, leading to the split system air conditioner leaking water.

Drain Line Disconnect

If the drain line isn’t attached correctly, it might disconnect, leading to the ac leaking water. A drain line can detach or loosen up over time due to incorrect installation after a repair.

In case of the drain line disconnects, moisture can gather on your home’s floor or escape through the ceiling. The leakage origin can vary depending on the placing of your drainage system.

Broken Condensate Pump or Float Switch

If you place your air conditioner in a location like a far away attic or basement, it isn’t ever easy for excess water to escape through the drain line. Here is where the condensate comes in. It’s able to clear out the excess water from the drain line and pan in your ac split system.

When the moisture level within the condensate pump reservoirs rises, the float switch automatically turns on, leading to the condensate pump draining the excess water outside your house. In case of a broken pump or a faulty float switch, you’ll have an air conditioner leaking water.

As a result of the system’s malfunction, water accumulates and spills from the indoor ac unit.

Condensation Build-up

Condensation buildup within your air conditioning system can occur  for several reasons;

  • When ductwork passes through attics with no insulation or inadequately insulated. An obstructed drain pump, dirty air filter, or clogged ducts can also cause ac water leakage.
  • Inadequate airflow within your air conditioner due to blockage causes the ductwork to sweat (condensation in the air conditioner ducts).
  • Excess humidity in the summer. Your home’s roof leaks and inadequate ventilation can lead to extra humidity levels. Ideally, a home’s humidity level should be below 50%.

Frozen Evaporator Coils

Evaporator coils are a component of the indoor unit, and because of a blocked airflow and refrigerant leak, they can freeze badly. The freezing of evaporator coils can result in water buildup, prompting the air conditioner’s drain pan to spill over water.

Unfortunately, you can’t fix evaporator coils that have frozen up on your own. You need an HVAC pro who will find out the leak’s source, select it and add more refrigerant.

Dirty Air Filters

As mentioned above, evaporator coils freeze up due to a dirty air filter. The filters guarantee proper air circulation within the system. They catch air pollutants, giving room for clean air to flow in your home.

However, combining these pollutants with dust might build upon the air filters, clogging them over time. The air filters’ blockage is harmful to your home’s indoor air quality.

Moreover, the blockage can damage a split ac system, leading to a weak HVAC airflow. When unwanted materials clog air filters, warm air won’t go past them quickly.

As a result, the AC’s refrigerant won’t be able to soak up the heat, freezing up the evaporator coils after some time. When air filters begin to thaw, you’ll likely see a reservoir of leaking water in your home.

How to Fix a Mini Split AC Unit Leaking Water

Condensate drain pipe blockage: accumulation of fungi, sludge, algae, mold, and debris can clog the drain line. Since the drainpipe won’t drain the water, it leads to an ac leaking water—requirements for fixing a clogged drain pipe; a vacuum cleaner, screwdriver, and a bucket.

Step 1: Open the panel or section to peel off the filters

Step 2: Disconnect the drain pipe

Step 3: Collect the excess water and place it inside a bucket

Step 4: Use the vacuum cleaner to suction out the drain pipe blockage

Step 5: Pour chlorine bleach or vinegar through the drain pipe

Drainpipe disconnection: drain pipes soak the excess water in the air conditioning system’s drip pan. If something has disconnected the drainpipe, it won’t empty the drain pan, leading to an ac leaking water.

Fixing a drain pipe disconnection – fixing this disconnection issue is simple. You only have to re-connect it to the air conditioning unit’s drain pan. However, if the drainpipe continuously disconnects itself, you’ll have to replace it. Replacement will help you with such disconnections in the future.        

Holes/cracks in the drain pan: rusting or corrosion leads to a damaged drainpipe with holes and cracks all over. The holes may result in an ac leaking water through your indoor unit. 

  • Fixing a drain pan with holes/cracks
  • Using a vacuum cleaner, clear out the excess water within the drain pan
  • Check for a water leak in the drain pan using a flashlight
  • Apply epoxy glue on parts that have a water leak

Dirty filters: Although tiny, they can freeze an evaporator coil due to insufficient airflow.

Fixing dirty air filters – for this, you’ll need a brush and some water. Else, you can replace the filters at the climax of the season or between 4-6 weeks.

Frozen coils: low refrigerant level freezes the coil, leading to water spill from your indoor split ac.

Fixing frozen coils – for this, you’ll need an HVAC pro since it’s hard to locate the source of the frozen coils if you aren’t familiar with air conditioners. Moreover, an HVAC pro will seal the leak’s source and boost its level to adequate.

Bad HVAC unit installation: while installing, you may have made some errors causing a split ac leak indoors.

Fixing an incorrect HVAC unit installation – if after conducting an ac checkup you find there isn’t an obvious water leak source, call an HVAC pro. Only professional HVAC service providers can fix the incorrect installation.

Faulty/burnt drain pump: in case the AC’s condensation pump is defective, or it has burnt out, it can lead to water dripping in your indoor split unit. Unfortunately, you’ll need an HVAC pro to help you check the split ac unit.

Fixing a faulty/burnt drain pump – book an appointment with an HVAC pro who’ll handle the problem correctly.  A reminder, don’t try to tinker with the air conditioner in the pretense of correcting it on your own.

Mini Split Leaking Water FAQs

Should my AC be leaking water outside?

Is it natural for a split ac to drain water outside? Well, it’s natural for an ac unit to drain a tiny amount of water when running since it generates condensation during that period.

Can we use AC when water is leaking?

If your aircon is leaking due to frozen coils, you shouldn’t power it on until you or the HVAC technician fixes it. If you continue using the HVAC unit while its coils are still frozen, you may badly damage your unit. Assuming a dirt buildup or blockage has caused the leak, you’re free to power on and use the aircon.

Can I still use my AC if it’s leaking?

If your aircon is leaking due to frozen coils, you shouldn’t power it on until you or the HVAC technician fixes it. If you continue using the HVAC unit while its coils are still frozen, you may badly damage your unit. Assuming a dirt buildup or blockage has caused the leak, you’re free to power on and use the aircon.

Should you turn off the AC if it is leaking water?

If your HVAC has a refrigerant leak, turn it off immediately since they are dangerous. Moreover, if you continue using an aircon with a refrigerant leak, you may bring about unnecessary damages to it. If the air conditioning unit is leaking due to frozen coils, It would be best not to power it on. Not unless you’ve fixed it.

What happens if your AC leaks water?

When materials like debris or dirt clog the condensate drain line, excess moisture can’t drain or escape outside your home. Condensation returns inside your house if some stuff has blocked the line. An easy way to clear up the line is by wiping it using a vac.


To this point, we’ve seen what causes a split ac to drip water and some possible solutions. I would advise you to act swiftly on your ac when you notice a persistent condensation puddle on it. Early intervention will save you from unnecessary leakages and repairs if needed.

So, if you religiously follow the above tips, you can fix a split ac that’s dripping water. Winding up, according to you, which DIY remedy do you think will work for you and why?