Here is How I Install Mini Split Condensate Drain Line

Josh Mitchell

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Josh Mitchell

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Holly Curell

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Effectively draining your mini-split condensate can be a difference between well-kept and ruined property.

With that in mind, I decided to present you with a beginner-friendly, step-by-step guide on how to install a mini split condensate drain line the proper way.

Key Takeaways

  • There are two condensate draining techniques: gravity draining and condensate pumps.
  • Gravity draining is the most common and popular technique and requires minimal efforts. The condensate pump allows for flexibility in draining, but the pump has to be bought separately.
  • Gravity draining technique works on all ACs and it is the same across all brands and models. 

How To Install A Mini Split Condensate Drain Line Yourself

You can use two types of drain lines for your mini-split air conditioner - gravity drain line and condensation pump drain line.

A gravity drain line should be your go-to option, so let's cover that first.
Supplies And Materials Needed
  • 5/8″ inner diameter vinyl drain tube
  • 7/8″ outer diameter PVC drain pipe
  • Appropriate PVC fitting

Step 1. Position The Mini Split For Optimal Drainage

Install the mini split unit high up on an outer wall so the drain line can run downwards and outwards seamlessly. 

The line should consistently slope downwards to ensure gravity can carry the condensate away.

ACLAB Note:

You will have to get into the wall to install the PVC drain pipe.

Step 2. Select The Right Drain Hose And Pipe

Choose a vinyl drain hose with an inner diameter of at least 5/8".

This size ensures adequate condensate flow away from the mini split unit.

For the drain pipe, choose the 7/8" diameter, only this time go for PCV.

Step 3. Install The Drain Pipe

The open end of your drain pipe should run outwards, so ensure it has a minimum slope of 1/8 to 1/4 inch per foot of run.

Be accurate in your measurements to eliminate the possibility of water retention within the drain pipe and thus minimize maintenance.

The in-wall section PVC pipe section should run straight up so it's easy to connect with a drain hose.

Step 4. Connect The Drain Line

Attach one end of the drain hose to the mini split unit's drain outlet, usually on the bottom or the side of the unit.

Ensure the connection is secure and leak-proof with a zip tie or an adhesive.

Attach the bottom of the drain hose to the PVC pipe using the appropriate fitting.

Step 5. Secure The Drain Line

Secure the line with clamps or supports every few feet to maintain the slope and prevent sagging or bending.

TL;DR: Gravity draining is an easy and the most commonly used technique for condensate draining.


Installing A Mini-Split Condensate Pump

If you can't install a gravity drain line, installing a condensate pump is the only other option to prevent leakage from your mini-split unit.

Step 1: Unbox And Understand Components

Start by unboxing the mini-split pump and identifying all components using the manual.

What you'll usually get in the box is:

  • Pump
  • Reservoir
  • Drain hose
  • Tube for connecting the mini-split drain to the reservoir
  • Reservoir breather tube

Step 2: Prepare The Pump And The Reservoir

In most cases, your pump will come with the small caps on the outlets, which you'll need to remove accordingly.

Choose the appropriate outlets on the pump for the tubing based on your setup, and reseal the other outlets with the caps.

What you can also do at this point is attach the breather tube to the top of the reservoir, ensuring it runs straight up to prevent overflow.

Step 3: Wire The Pump

Firstly, disconnect the power to the AC.

Secondly, depending on where you intend to keep your pump (I'd suggest a drop ceiling due to the noise), feed the pump's wires in the most unobtrusive and discreet way.

As for the wiring itself, you must follow the mini-split's wiring guide.

Those can be tricky to decipher, but I can't give you the specific instructions, as you will have to wire in the correct voltage setup and also ensure you connect the wires to the appropriate terminals.

Step 5: Secure Hose Connections

Once all wired up, connect the hose from the mini-split to the reservoir and from the reservoir to the pump (these hoses will come with the pump).

Ensure clean, tight connections, using zip ties for security.

Step 6: Mount The Pump And Reservoir

You can mount the condensate pump in the drop ceiling, wall-mount it with brackets, or secure it in the air handler portion of the AC - wherever you deem fit.

The reservoir must be mounted at a 90-degree angle and underneath the pump to ensure gravity does its job.

Step 7: Install Drain Lines

In the end, route the drain hose(s) from the pump to an appropriate drainage point, such as an external drain or your backyard.

Ensure the pipes have a downward slope and avoid curving for unobstructed drainage.

ACLAB Note:

You will have to buy a drain hose separately.

TL;DR: Condensate pump gives you the ability to drain the AC to a higher elevation. However, you have to procure the pump yourself.


Do Different Mini Split Brands Require Different Drain Line Installation?

Installing the condensate drain line does not differ from brand to brand.

Repeating the drain line installation steps outlined above will work regardless of the make or model of your AC.

What I have noticed differs from brand to brand (as well as model to model) is wiring the condensate pump.

As not every pump has the same wiring scheme, and neither do mini-splits, opening up the manual and precisely following instructions is paramount.

For example, some Samsung mini-split air conditioners have this extended plug for drain pump interlocking, which is essentially a safety mechanism that prevents communication errors between the pump and the AC.

TL;DR: Generally, there is no difference in using gravity draining for ACs from different brands. Some difference may be seen when installing a condensate pump for draining.

Where Do You Put A Mini Split Drain?

There is no set place for a mini-split drain line location, as you can install it in several ways.

However, there are three general guidelines you should follow.

  1. 1
    Near an External Wall:
    Ideally, the mini-split drain should be located near an external wall of the building for easy routing of the condensate drain line to the outside.
  2. 2
    Above Ground Level:
    The drain outlet should be positioned above ground level to facilitate gravity-assisted flow of the water and prevent backflow.
  3. 3
    Accessible Location:
    Choose a location that is accessible for annual maintenance.

On a more specific note: 

  • You may be able to run the drain line to an existing drain hole in the wall if you are installing a mini-split in an existing home. 
  • You can plan for the drain line to run to a drain hole in the foundation or crawlspace if you are installing a mini-split in a new home. 
  • You can drain the water out in the yard if you are installing a mini-split in a home without an external drain. 

TL;DR: There are several recommended locations for putting the condensate drain. The most common is near an external wall with easy accessibility.


FAQs

How Much Condensate Does A Mini-Split Produce?

A mini-split air conditioning unit can produce around 5-20 gallons of condensate in a day, depending on the conditions and the runtime.

Does A Mini-Split Need A Condensate Trap?

In most cases, a mini-split does not need a condensate trap for proper drainage. However, a ducted or ceiling-concealed mini split requires a condensate trap to drain appropriately.

Do Mini-Splits Drain Need Insulation?

Mini-split drain lines do not need insulation. However, if you live in extreme conditions (high temperatures and high humidity)condensation can occur on the drain pipes which may call for pipe insulation.

Do Mini-Splits Condensate In Heat Mode?

No, mini-splits do not condensate water while operating in heat mode.

Final Words

As you can see, installing a mini-split condensate drain line is a job you can do in no time without hiring a contractor.

As long as you have your mini-split installed in a suitable location, cutting through some drywall and routing the vinyl hose and PVC pipes to the nearest drain (or the ground) is essentially all you have to do.

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Josh Mitchell

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Josh Mitchell
My name is Josh and I am obsessed with home appliances. From portable AC units to heaters and air purifiers, I enjoy testing, learning and using these devices to improve the air quality inside my family home.

My Favorite Home Appliance?

Midea U Shaped Window Air Conditioner

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