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Fix a portable AC that leaks

We'll check the drain plug, hose, tilt, drain pan, and condensate pump—or tell you when to call a pro.

Troubleshooting · Home appliances
10–30 min
What you'll need
  • Level (optional)
  • Mild soap and cloth for cleaning
  • Replacement drain hose (if cracked or damaged)
Step 1 of 8

Quick triage — pick your path

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Choose the option that matches what you see. You can jump straight to that section.

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Steps

Goal: Confirm the leak source, then clear the drain path.

  • Trace the water to its origin. Confirm it is from the portable AC, not a window, ceiling, or nearby source.
  • Good: Water is from the unit. Proceed to Check drain path.
  • Bad: Water is from elsewhere—fix that source.

Check drain path

Goal: Rule out drain plug and hose issues.

  • Check the drain plug at the bottom. For continuous drain mode, remove the plug and attach the drain hose. For evaporative mode, the plug stays in—check your manual.
  • Inspect the hose for kinks, clogs, or loose connections. Disconnect and run water through it to test. Reconnect firmly.
  • Good: Plug is removed (if using hose) and hose is clear. Proceed to Check tilt and drain pan.
  • Bad: Plug was in or hose was blocked—fix and retest.

Check tilt and drain pan

Goal: Confirm the unit drains correctly and the pan is not overflowing.

  • Confirm the unit is level or tilted toward the drain outlet per the manufacturer. Use a level.
  • Unplug the unit. Remove and empty the drain pan if accessible. Clean it. Check for cracks.
  • Good: Tilt is correct and pan is clean. Proceed to Condensate pump.
  • Bad: Wrong tilt or dirty pan—fix and retest.

Condensate pump

Goal: Confirm the condensate pump works if your unit has one.

  • When the AC runs, listen for the condensate pump. It should move water to the window or drain.
  • If the pump does not run or hums but does not move water, it may have failed—call a technician.
  • If there is no pump (gravity drain only) and the path is clear but it still leaks, call a technician.

When to get help

Call an HVAC technician if:

  • The drain path is clear, the unit is tilted correctly, and it still leaks.
  • The condensate pump has failed.
  • You see refrigerant oil (slick, oily residue—different from clear condensate).

Verification

  • No water dripping or pooling around the unit.
  • Drain hose runs downhill with no kinks.
  • Unit is tilted per the manufacturer.
  • Drain pan is clean and empty.

Escalation ladder

Work from the device outward. Stop when the problem is fixed.

  1. Confirm leak source Verify water is from the AC, not a window or ceiling.
  2. Drain plug and hose Remove plug if using hose; check hose for kinks and clogs.
  3. Tilt and drain pan Confirm unit is tilted toward drain; empty and clean drain pan.
  4. Condensate pump Check that the pump runs and moves water.
  5. Call a pro Drain path clear, tilt correct, still leaks—or pump failed.

What to capture if you need help

Before calling support or posting for help, have these ready. It speeds everything up.

  • Drain plug in or out
  • Hose condition (kinked, clogged, loose)
  • Unit tilt and level
  • Whether condensate pump runs
  • Steps already tried

Is water coming from the portable AC?

Trace the water to its origin. Condensate is clear. Check window, ceiling, and unit.

Confirm the leak is from the AC, not from a window seal, ceiling, or nearby source. Trace the water. Good: water from the unit—proceed. Bad: water from elsewhere—fix that source.

Yes No

You can change your answer later.

Fix the other source

Water is from a window seal, ceiling, or nearby source—not the AC. Fix that source. This guide is for leaks from the portable AC itself.

Done

Is the drain plug removed and hose clear?

For continuous drain, plug must be out. Hose must have no kinks or clogs.

Check the drain plug—remove it if using the drain hose. Inspect the hose for kinks and clogs. Run water through it to test. Good: plug out, hose clear. Bad: plug in or hose blocked—fix first.

Yes No

You can change your answer later.

Fix drain plug and hose, then retest

Remove the drain plug if using continuous drain. Clear the hose of kinks and clogs. Run water through it to test. Reconnect firmly. Run the AC and check if the leak stops. If it still leaks after fixing, proceed to check tilt and drain pan.

Done

Is the unit tilted toward the drain and pan clean?

Unit must tilt toward drain per manual. Drain pan can overflow if blocked.

Confirm the unit is tilted toward the drain outlet per the manufacturer. Empty and clean the drain pan. Good: tilt correct, pan clean. Bad: wrong tilt or dirty pan—fix and retest.

Yes No

You can change your answer later.

Fix tilt and clean pan, then retest

Adjust the unit so it is tilted toward the drain outlet per the manufacturer. Empty and clean the drain pan. Run the AC and check if the leak stops. If it still leaks after fixing, the condensate pump may have failed—call a pro.

Done

Does the condensate pump run and move water?

Some units have a pump. If it fails, water backs up.

If your unit has a condensate pump, listen for it when the AC runs. It should move water. Runs and moves water: good. Does not run or hums but no flow: pump failed—call a pro. No pump: gravity drain only—if path is clear and still leaks, call a pro.
Question

Does the condensate pump run and move water?

Done

Call a technician

Call an HVAC technician if: the drain path is clear, the unit is tilted correctly, and it still leaks; the condensate pump has failed; or you see refrigerant oil (slick, oily residue).

Done

Reviewed by Blackbox Atlas

Frequently asked questions

Why would a portable AC leak water?
Common causes: drain plug in place when using hose, kinked or clogged drain hose, unit not tilted correctly, condensate pump failure, or overflowing drain pan. Check the drain path first—plug, hose, and tilt.
Can I fix a portable AC that leaks myself?
Yes, for drain plug, hose, and tilt. Clean the drain pan and hose. If the condensate pump has failed, you may need a technician. Internal refrigerant leaks are rare—call a pro if you suspect one.
When should I call a technician for a portable AC leak?
Call a technician if the drain path is clear, the unit is tilted correctly, and it still leaks; the condensate pump runs but does not move water; or you see refrigerant oil (slick, oily residue—different from condensate).

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