Water Dripping From Split AC Indoor Unit? (Fix It Now!)

Stacy Randall
by Stacy Randall

When you’re running your split AC unit, the last thing you want to see is dripping water. Unfortunately, your AC unit will sometimes end up leaking, and you’ll have to figure out the problem. Luckily, you can likely fix many of the potential issues yourself if you’re comfortable fooling with the AC components.

Several reasons can cause a dripping split AC indoor unit, including a blocked condensation drain pipe or disconnected drain line. Other potential causes you could handle yourself are dirty air filters or a cracked or damaged drip pan. Sometimes, you’ll need to call a pro; faulty installation, low refrigerant, or condensation pump issues can also cause drips.

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Diagnosing and Fixing Your Dripping Split AC Indoor Unit

Of course, before you can fix the problem, you need to figure out the problem. A split air conditioner consists of two main parts: an outside compressor and an interior air outlet unit.

A series of pipes, instead of ducts, connect the two units. The refrigerant flows through these pipes to generate cold or hot air. Sometimes, the inside unit will drip, which can be a real pain, but not necessarily a major hassle to fix.

In many cases, you can likely handle the fix yourself if you feel comfortable. However, if you don’t have the proper tools or are unsure, it is best to call an HVAC professional.

Most likely, one of the following issues is the cause for your dripping split AC unit:

  • Blocked Condensation Drain Line
  • Disconnected Drain Line
  • Dirty Air Filters
  • Broken Drip Pan
  • Low Refrigerant
  • Condensation Pump Issues
  • Faulty Installation

How to Fix a Blocked Condensation Drain Line

As your AC runs, over time, water accumulates inside from condensation, which is normal. This is why the unit has a condensation drain line.

However, sometimes, the buildup of various materials, like mold, sludge, algae, and other debris can block the AC’s drain line. When this happens, the collected water within the unit can’t drain properly. Since the water has no designated place to go, it spills out into your home.

If the issue with your dripping AC is a blocked drain line, follow these steps to solve the problem.

Tools You Need for the Job:

  • Vacuum with long hose attachment
  • Screwdriver
  • Bucket
  • White Vinegar

Step 1: Open the Unit and Remove the Filters

Use a screwdriver to remove the front panel of your AC unit. Set the panel to the side and remove the filters so you can see the unit’s interior. This is also an excellent time to note the condition of the filters to see if they need a cleaning. If so, follow the steps below for what to do with dirty air filters.

Step 2: Locate and Disconnect the Drain Pipe

Locate the pipe that drains water from your unit. This pipe is typically a ¾” PVC pipe that leads outdoors. Place the bucket under the pipe when you disconnect it to catch any water collected inside the pipe.

Step 3: Clean Out the Drain Pipe, Flush, and Reconnect

After you completely drain the pipe, suck out the blockage with the vacuum and hose attachment. Finally, pour between a ½-cup and one cup of vinegar down the drain to help rid it of any bacteria. Replace the filters and the unit’s front panel.

How to Fix a Disconnected Drain Line

When your AC sucks the humidity out of the air, it collects in the drip pan. The water that collects in the drain pan then flows out through the drain line. But, if the drain line gets disconnected or is connected wrong, then the drip pan will eventually overflow. This overflow turns into a leak inside of your home.

This is a relatively simple fix. All you need to do is ensure that the drain line is connected to the drip pan correctly. If this does not solve the issue, the drain line might be damaged, in which case you must replace it.

What to Do with Dirty Air Filters

Air filters help keep dust and other debris from passing into your AC unit. The filters also help keep coils and other components of the unit clean.

However, if you don’t clean or replace the air filters regularly, then dirt can build up and start causing issues. When the air filters are dirty, they prevent the proper passage of air. In turn, this can lead to freezing evaporator coils and other issues — like leaks.

Luckily, this is another easy fix. To clean the air filters, simply use a soft brush or rag and some water to wipe each side of the filter. You should also replace your filter every three months and closer to every month during the peak season.

What to Do If There Is a Damaged Drip Pan

Another possibility for your split AC unit’s dripping problem is a damaged or cracked drip pan. Over time, the drip pan can develop holes or other issues, either from rust, corrosion, or other wear. When this happens, the water will simply leak through these compromised areas.

Tools You Will Need for the Job:

  • Wet-Dry Vacuum
  • Epoxy glue
  • Flashlight

Step 1: Get Rid of Standing Water

First, use the vacuum to get rid of any standing water so you can examine the drip pan thoroughly.

Step 2: Locate and Repair Cracks

Once the drip pan is empty, examine it closely with the flashlight. Ensure you locate every hole and crack, and use the epoxy glue to fill all of these areas. Follow the directions on the particular glue that you use, and allow the glue to dry for the recommended time.

If this does not solve the issue, or there are too many cracks or holes, you will have to purchase a new drip pan. Drip pans vary in price based on size and material. However, you can typically buy them between $30 and $50 from a home improvement store or online.

Reasons to Call a Professional for Your Dripping Split AC Unit

In some cases, the reason your split AC unit is dripping will be a bit more than you can potentially handle. If none of the above DIY fixes solved your problem, it’s best to call in a professional HVAC service. Likely, your unit has one of the following issues.

Low Refrigerant

If the refrigerant in the unit is low, it can cause the evaporator coils to freeze. When the coils freeze, it can lead to leaks in the indoor unit. You should never top off the refrigerant in your unit.

Only qualified technicians are supposed to handle refrigerants. Plus, if your refrigerant is low, this usually points to other potential problems with your system. Therefore, call a pro to assess your system and handle the issue for you.

Problems with the Condensation Pump

If the condensation pump inside the unit experiences any issues, it can lead to water leakage. You need a professional to check the pump for any potential problems or damage. If it isn’t the pump, at least a specialist can then identify the exact cause of the dripping.

Faulty Installation of Your Split AC Unit

Unfortunately, leaks can occur from poor installation. If you have had your air conditioner for a while without issue, then the installation is likely not the problem. However, if it’s a fairly new system, then incorrect installation could be to blame.

If this is the case, contact the HVAC service that installed your unit as it is probably still under warranty. The pros can assess the entire system and fix anything that is not correct. This is not something you should tackle on your own.

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Related Questions

How often should you service a split AC unit?

Whether or not you’re experiencing issues with your AC system, it needs to be inspected and cleaned once a year. The same also goes for your heating system. Your yearly service typically includes cleaning out the unit and replacing the filters. If you are experiencing issues with your AC, then call a professional sooner. If you let problems go unchecked, then small issues can lead to more significant (and costlier) problems.


What is the average cost of repairs for a split AC unit?

The average cost for AC repairs is roughly $300, although it can range from around $75 to over $1,000. If it is a simple freon leak, it can be relatively inexpensive to fix. However, if there are damaged parts, this can be more costly. In addition to parts, there is also typically a service call fee of between $50 and $100. For labor, HVAC technicians charge anywhere from $50 to $150 an hour, depending on the company and location.


What is the average lifespan of a split AC unit?

Typically, a split AC unit (also referred to as a mini-split ductless system) lasts for about 20 years. This is about 5 to 7 years longer than a conventional AC unit. Of course, proper maintenance and care play a big part in how long your unit lasts.

Stacy Randall
Stacy Randall

Stacy Randall is a wife, mother, and freelance writer from NOLA that has always had a love for DIY projects, home organization, and making spaces beautiful. Together with her husband, she has been spending the last several years lovingly renovating her grandparent's former home, making it their own and learning a lot about life along the way.

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