Is Your Portable Air Conditioner Leaking? Here’s How to Fix It

Researched & Written by Craig

I hate leaks.

They’re annoying, unannounced, wet, and sometimes smelly!

Of course, I’m talking about leaky portable air conditioners.

Pair of Leek Vegetables

No offense, my green friends.

Especially when it comes to my portable air conditioner, finding a leak will really put a dampener on my day.

In response, I dove into a few hours of research. I’ve consulted dozens of articles and forums to find all the potential causes and solutions to a leaky portable AC. And I’ve put all of them together in this simple guide.

Fix a leaking portable air conditioner by finding if it’s an overflow or a fault. If the leak is from an overflow, get the portable air conditioner level and check the float. If the leak is structural, contact the air conditioner manufacturer.

A leak in your portable air conditioner can mean many things. None of them good! It can be as simple as needing to empty the basin more often, to giving a faulty performance. And costing you more in energy bills each month. So let’s figure out how to tackle it together.

For those not in a rush – read on and I’ll walk you through each issue and solution one by one.

Drainage Types

Before we go any further, it’s important to understand the two drain types.

Dehumidifying is a vital part of any air conditioner. If hot and humid air is cooled but no dehumidified, we just end up cool but clammy. It feels pretty horrible! So air conditioners all work to take moisture out of the air as they cool. And that moisture needs to be drained somewhere.

Any portable air conditioner will either be a manual-drain, or an automatic-drain.

Manual means that the water flows into a basin, which you need to empty regularly. Often the air conditioner will refuse to dehumidify any more if the basin gets full. If the weather has been super-humid, the basin will be filling quickly and need emptied more often. Alternatively, an automatic-drain is connected to your utility system via a drainline. Any water flows down the line and shouldn’t need worried about.

Make sure you know which one you have – because the tips below cover both!

So You’ve Found A Leak. What Now?

Let’s take things step by step. Starting from the moment you notice a damp or wet patch around your air conditioner.

1. First, let’s drain it. If the AC is a manual drain, then unplug the cap and fully drain out of water. Make sure to have a container ready to collect the waterfall!

2. Inspect the unit. Look for any rust, excess grimes, and structural holes. Check the float detector in the water container. Is it obscured? Does it look like it’s working properly?

3. Assess. Leaks are either caused by overflow (super humid conditions, faulty float detector), a clogged drain, or a structural fault (rusted holes, structural cracks).

Now let’s go through each type of potential problem, and how to solve it.

Manual Drain: It Could Be Overflowing.

Want some good news? This is the easier problem to deal with.

Overflow can be from a few reasons. Including

  • The float detector isn’t working. Every manual-drain air conditioner should track how full it’s basin is. When it’s at capacity, the air conditioner should shut off to prevent overflow. (And get your attention since it’s not working!). This can often be caused by:
    • The unit not being level. The water level is at a slant, and the float is at the higher end. Meaning the lower end overflows. Simply get the unit level to fix this.
    • The detector is obscured by grime, dirt, or some other thing. A quick clean and check that it can move properly is all you need.
    • It otherwise plain isn’t working. This may be a more internal system problem, and you’ll need a technician’s help.
  • Overuse and/or crazy conditions. Portable air conditioners can be gamechangers, but they can’t take on the world. If your AC has been running constantly on max, and the climate is super humid, then the unit is probably sweating out more water than a waterfall.
    • There’s not much to fix here – it’s just the conditions. Your best bet is to MacGyver together a better drainage bucket. Try raising the unit up on props and placing a larger bucket/container below. Otherwise just make sure you’re draining the unit regularly.

Automatic Draine: What About The Drain Line?

If you have a model that drains automatically, the problem could be with your drain line.

There’s a few common issues here. Some are easy to solve, others aren’t…

  • Faulty plug/cap. This is the best option – the drain line simply isn’t sealed correctly. Just take off the plug or cap and place it back on properly to complete the seal.
  • Clogged line. Over time, drains can naturally get blocked due to grime or debris. If the drain line is accessible – great! Just use a metal wire (with the AC off) to dislodge the blockage. If you can’t get access, you’ll need to call for backup from the manufacturer. One thing worth trying is adding a tablespoon of bleach around the clog or opening, and letting that sit for a few hours.
  • Faulty line. If you’ve had the air conditioner for a good few years, the drain may have just sprung a structural leak. If you can find it – some duct tape might do the trick. Otherwise, it’s a call for the manufacturer, or a replacement ac part.

Structural Damage

One of the worst cases is a real structural leak. These can be caused by:

  • Rusted holes in basin. Every appliance rusts to some degree, but a severe result can be a hole clean through the water basin. Try your best to solve with a patch-repair, or some other way to stop the leaking. Or, if possible, replace the basin altogether.
  • Cracks in the system. Cracks can be caused from overuse, moving around, or simply during manufacturing. There’s some horror stories of units being delivered with a hole drilled into the water basin! Again, try to patch repair and seal any cracks that you can. Simple window sealant can do the trick. But there’s not much we can do if that doesn’t work – other than get a replacement.

Other Causes

Last up are two more miscellaneous faults than can cause water issues.

  • Dirty air filter. If it’s been far too long since you’ve cleaned your air filter, this can cause a lot of internal condensation that looks like a leak out the bottom. Especially because the blocked airflow goes back over the evaporator and freezes the coils. All you need is to do what your manual says – clean the filter regularly! If it’s beyond saving, replacements are always available.
  • Refrigerant leak. The other, much scarier, cause of frozen coils is a leak of the AC’s refrigerant. If water is leaking from somewhere inside, and the air conditioner sucks at cooling recently, you may have a refrigerant issue. Especially if ice has started to cover the coils. Another tell-tale sign is hearing fizzing/hissing from the back of the unit. If you believe this is what’s wrong, the only solution is to call the manufacturer. If it’s out of warranty, I’d start looking for a new model!

Wrap Up

A leak in your air conditioner is never a good sign. It means you’re probably not getting the most from your air conditioner, and potentially paying extra in energy bills.

I hope this quick guide has helped give you some ideas about what might have gone wrong, and solutions to try.

Wishing you and your air conditioner a leak-free future!

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Thanks for reading, and have a great day 🙂

Craig