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Portable AC Keeps Spitting Water? Here’s Why (+ How to Fix)

Portable air conditioners can cause a few problems because of their self-contained, compact designs. While some brands have improved their flagship models in recent years, several portable ACs continue to have a few typical and unacceptable issues, such as spitting water. If your portable AC is spitting water, you need to get to the bottom of it to figure out a solution. 

Here are 12 reasons why your portable AC is spitting water:

  1. The condensate line is clogged.
  2. The condenser drain pan is full.
  3. The drain spout/hose is jammed.
  4. The condensate pump has failed. 
  5. The float switch isn’t functioning.
  6. The relative humidity is too high.
  7. The unit and its air filters are dirty.
  8. The evaporator coil may be frozen.
  9. The blower isn’t working properly.
  10. The exhaust system has problems.
  11. The AC has low or leaking coolant.
  12. The portable AC has a major defect.

A few of these reasons apply to specific portable ACs with the corresponding components, like the draining system, condensate pump, etc. Keep reading to investigate and troubleshoot all the probable issues with a portable AC spitting water. 

1. The Condensate Line Is Clogged

Portable ACs don’t have the same design as a window air conditioner. I’m excluding mini splits, cassettes, and central air conditioners in this discussion because those have two separate units. Only window and portable ACs have one self-contained unit, so their comparison is fitting.

Unlike window air conditioners, a portable AC has the evaporator coil above the condenser. The evaporator unit has the blower, while the condenser coil has the exhaust fan. The two separate sections have 4 shared elements:

  • Coils
  • Airflow
  • Compressor
  • Condensate

The first and most common reason for portable ACs spitting water is a clogged condensate line.

The condensate line is the system that allows water from the evaporator chamber to flow down to the condenser unit. Now, this system isn’t technically or literally a line because the water flow is facilitated by a few holes. These drain holes are at the base of the evaporator unit.

Here’s what happens to the condensate inside a portable AC:

  • Water condenses in the evaporator chamber.
  • This condensate trickles down the evaporator coils.
  • Ideally, the condensate must flow to the drain holes.
  • These drain holes are under the evaporator housing.
  • Subsequently, the water will accumulate in the drain pan.
  • This drain pan is at the very bottom of your portable AC.

Now, the condensate won’t flow to the drain pan below if the holes in the evaporator housing of your portable AC are clogged. What you’ll have is water buildup inside the evaporator chamber. This water has nowhere to go except to be blown out through the vents along with the airflow.

These drain holes are vulnerable to clogging due to a gunky buildup. Our homes or rooms aren’t dust-proof, and portable ACs keep recirculating the indoor air. While the air filters are supposed to trap as much particulate matter as they can, these are hardly impeccable at blocking all dust.

Fortunately, this common problem has a relatively straightforward solution. Here’s what you can do to stop your portable AC from spitting water:

  1. Get the user manual for your model or download a copy. 
  2. Unplug the portable AC and get a pan, a towel, and a screwdriver.
  3. Remove all the screws to take off the covers and access panels.
  4. You’ll find the evaporator chamber with the blower in insulated housing.
  5. Usually, this insulated housing is expanded polystyrene (EPS), or Styrofoam.
  6. Don’t damage the housing or any other components during this troubleshooting.
  7. In some models, you may have to remove the housing to access the drain holes.
  8. There should be two or more drain holes below the evaporator and blower housing.
  9. Get a pen, wire, or something similar to clear the drain holes if they are clogged.
  10. Check if there’s any debris buildup on or around the evaporator and blower.
  11. Since water trickles down these parts, there are nondescript condensate lines in action.
  12. Clean any blockage that may prevent the condensate from flowing to the drain holes.
  13. Let the condensate flow into the drain pan at the bottom of your portable AC.
  14. Place your pan under the drain spout and keep the towel handy to manage any spills.
  15. Open the drain spout and let the condensate flow out until the onboard pan is bone dry.
  16. Reassemble your portable air conditioner, replug it, and check if it spits water again.   

Generally, the evaporator and other internal components of a portable AC are accessible after removing the rear covers. You need to check the types of screws to get an appropriate driver. Some access panels or covers may need gentle wiggling and prying during disassembly. 

2. The Condenser Drain Pan Is Full

Suppose the condensate line or drain holes through the evaporator housing aren’t clogged. Your AC may still have excess condensate accumulating in the evaporator chamber if the drain pan is full. However, an overflowing drain pan should trigger the float switch and shut a portable AC.

Also, if your portable AC has a gravity-fed drain line or condensate pump, the pan or tank at the bottom of the unit shouldn’t overflow. But all these functions are in a normal situation, in which case your portable AC won’t be spitting water in the first place.

So, check if your condenser drain pan is full. An overflowing drain pan or tank without a hose or condensate pump will cause water to back up to the evaporator, and the portable AC might spit water.  

Most portable ACs have an error code as the float switch activates and shuts the unit. Models like the LG LP1213GXR display FL when the water collection tank is full. You must empty the drain pan or water collection tank periodically.

3. The Drain Spout/Hose Is Jammed

Some people use a gravity-fed drain line for continuous condensate outflow from a portable AC. If this gravity-fed drain hose is clogged or the spout on the appliance is jammed, a unit is likely to have water buildup inside the pan. You must clear the drain spout and keep the hose clean.

Portable ACs don’t have the drain spout in the exact position or alignment at the base. If this spout doesn’t allow an uninterrupted outflow, the condensate may accumulate in the pan. Also, ensure your portable AC is leveled, and the gravity-fed drain line is consistently sloped.

Furthermore, drain lines or hoses require routine cleaning. You may use a pressure washer or compressed air to clean the hose and confirm that the line isn’t kinked or chipped anywhere. 

4. The Condensate Pump Has Failed 

A few portable ACs have an onboard condensate pump. Unlike the continuous drainage through a gravity-fed hose, a condensate pump activates only when the water reaches a certain level. If the pump fails or its hose is clogged, your portable AC may have excess water in the drain pan.

Some people use an external condensate pump, especially when a gravity-fed drain line is not feasible. You may have the same problem if this external condensate pump fails. Often, portable ACs leak water when such drainage systems fail. So, you may have more than one problem. 

5. The Float Switch Isn’t Functioning

Ideally, the drain pan in your portable AC shouldn’t overflow because the float switch is meant to shut the unit before it leaks water. But this critical part may fail, and your portable AC may leak or spit water. So you should inspect the float switch, its alignment, and whether or not it is clean.

A float switch may get stuck due to gunk buildup inside the drain pan. A misaligned water level sensor may also be a problem. Also, you may have a faulty float switch, in which case you must replace it. But not all float switches are easily replaceable, so check with the manufacturer.

Except for the clogged drain holes in the evaporator and blower housing, the other condensate and drainage problems I have discussed until now are correlated. Here’s a checklist to simplify your inspections:

  1. Check if the drain pan or water collection tank is full and empty it.
  2. Investigate a faulty float switch if the portable AC leaks or spits water.
  3. Inspect a gravity-fed drain line for clogging, kinks, bends, and improper slope.
  4. Clean the drain hoses, whether it is gravity-fed or connected to a condensate pump.
  5. Suspect the condensate pump, whether external or integrated, if everything else is fine.

6. The Relative Humidity Is Too High

A portable AC may spit water if the relative humidity is too high on a hot day. Portable ACs reduce the humidity in a room to an extent, but they aren’t dehumidifiers, and the cooler air exacerbates the problem. Dehumidifiers don’t circulate cool air, so condensation isn’t a concern.

High humidity slows evaporation because the indoor air is already saturated with moisture. So, the water inside a portable AC doesn’t evaporate as swiftly as in low humidity conditions. This phenomenon leads to more water buildup inside the AC. 

Also, the cool and hot air interacting inside the AC and at the vents causes more condensation in highly humid conditions. This double impact of greater condensation and slower evaporation is why your portable AC spits water when the humidity is too high.

High humidity isn’t a portable AC’s fault. You can use a dehumidifier if you live in a hot & humid region. Also, increase the AC temperature so that the air isn’t too cool for rapid condensation. A larger temperature difference between indoor air and AC airflow causes greater condensation.

7. The Unit and Its Air Filters are Dirty

Portable ACs may spit water if they are dirty, especially the air filters. Poor airflow inside the AC impairs the efficacy and efficiency of heat exchange at the evaporator and condenser coils. And an unclean unit may have clogged drain holes in the evaporator housing, as I explained above.

You should clean the air filters frequently and the entire unit periodically. Some brands suggest cleaning the air filters fortnightly, but you can decide based on your usage and how dirty the unit is. Also, replace one or both air filters if they are no longer usable.  

8. The Evaporator Coil May Be Frozen

A frozen evaporator coil increases condensation. This excess water may not drain as quickly as a normal volume. Also, the blower’s action may force some droplets out of the vents, and the portable AC will spit water. 

An AC evaporator coil may be frozen due to the following reasons:

  • Dirty air filters and poor airflow as a result.
  • Grimy evaporator with poor heat exchange.
  • A weak blower motor or broken exhaust fan.
  • Blocked drain holes and excess condensate.
  • Low or leaking coolant in the evaporator coil.

9. The Blower Isn’t Working Properly

A failing or weak blower may lead to ice buildup on the evaporator coil. As this ice melts, the AC will have excess water in the evaporator and blower chamber. Hence, your portable AC may spit some water from the melting ice.

Also, an ineffective or inefficient blower impairs the heat exchange at the evaporator. The lack of adequate airflow in the AC slows and limits the evaporator’s cooling of the warm air. Hence, the evaporator coil may freeze, and you might have an ice and spitting problem. 

10. The Exhaust System Has Problems

The condenser fan in portable ACs exhausts moisture-laden air through the vent and duct. If this fan doesn’t work properly or the duct hooked to your wall has problems, your portable AC may have excess condensate, and it may spit water. 

A dusty or failing condenser fan is less efficient. So, the condenser coil won’t cool effectively. A leaky or clogged duct has the same effect, and your AC is likely to have more condensate in the drain pan. Also, rainwater may seep into the duct and cause water buildup inside the AC.

Here are the remedies for the different issues you may find:

  • Clean a dusty condenser fan or replace a broken one.
  • Ensure the exhaust vent and duct are clear and sealed.
  • Bend the flexible duct to avert moisture backing up in it.

11. The AC Has Low or Leaking Coolant

Leaking coolant will ice up on the coils. A low refrigerant level can have the same effect. Also, leaking coolant is a hazard, so you must immediately contact a certified HVAC technician or the manufacturer. 

You shouldn’t have to worry about low coolant unless there is a leak. The entire cooling system comprising the compressor, condenser, and evaporator is sealed. Hence, you shouldn’t have a low coolant pressure or volume unless a refill is inadequate or there’s a leak in the system. 

12. The Portable AC Has a Major Defect

The cooling system of a portable AC has several critical features. For instance, there is a valve in the coils that allows the coolant to expand as it flows into the evaporator. If this valve is faulty, your portable AC won’t work as it should. 

Major defects in portable ACs may or may not cause your unit to spit water. However, if nothing else in this guide is the problem, you have to contact the manufacturer or a local, certified HVAC technician for a hands-on inspection.


  • Chris Hewitt

    Chris is a Texas-based freelance writer who loves the outdoors and working in his garage. When he's not enjoying the Texas sun, he can be found tinkering with all sorts of things in his workshop.

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