Step-by-Step DIY Installation: How I Set Up My Easy Pro 12 k

By Samantha — your neighbor who loves a good DIY Saturday.

---

Installing a ductless mini-split used to sound intimidating—until brands like MRCOOL made it genuinely DIY-friendly. When I installed the MRCOOL DIY Mini-Split Easy Pro Series 12,000 BTU Wall Mounted Ductless Heat Pump System, I realized just how approachable it can be with the right prep and patience.

This post walks through my process—what I used, how I mounted it, how the quick-connect lines snapped in perfectly, and a few of my “learned-the-hard-way” tips (like labeling your cables before drilling!).

---

🧰 1. Before You Start — What’s in the Box and What You’ll Need

The Easy Pro 12 k kit comes impressively complete. Inside, you’ll find:

• Indoor air-handler unit

• Outdoor condenser

• Pre-charged refrigerant line set (usually 16 ft or 25 ft, depending on your model)

• Wall bracket for indoor unit

• Wall sleeve for line-set pass-through

• Remote control and Wi-Fi dongle (if included)

• Mounting hardware and drain hose

What you’ll still need to gather on your own:

Samantha’s Tip #1:

Lay out everything on a tarp before you start. A clear workspace = fewer mistakes.

(Home Depot DIY HVAC Tool Checklist — homedepot.com)

---

🏠 2. Choosing the Perfect Spot for Your Indoor Unit

Ideal Placement

The indoor head should sit:

• Around 7–8 ft above the floor for best air distribution

• At least 6 inches below the ceiling

• 2 ft clearance on each side for smooth airflow

• Close to an exterior wall where the line set can exit directly outside

Avoid direct sunlight, heat sources, or locations above shelves or doors.

Why It Matters

A poor location can cause uneven cooling or sensor misreads. The Easy Pro’s thermostat sits inside the unit—so airflow and circulation matter more than you’d think.

(Energy.gov Ductless Mini-Split Air Conditioners)

---

🧩 3. Mounting the Indoor Unit

Here’s the fun part. Once you’ve picked your spot:

Step 1 – Find Studs and Level the Bracket

Use a stud finder to locate solid backing. Mark holes and use a level before drilling. Uneven mounting leads to condensate drainage issues later.

Step 2 – Drill Anchor Holes

Drill pilot holes through drywall and into studs (or use heavy-duty wall anchors).

Step 3 – Attach the Bracket

Screw the mounting plate securely, checking for level again.

Step 4 – Mark and Drill the Line-Set Hole

• Use the supplied template to mark a 3.5-inch hole.

• Drill slightly downward toward the outside for drainage.

• Insert the plastic wall sleeve.

Samantha’s Tip #2:

Label your cables before drilling.
It sounds silly, but once the lines, power cable, and drain are all bundled, it’s easy to mix up ends. A bit of painter’s tape with “Power,” “Drain,” and “Line A” written on it saved me hours later!

---

🌬️ 4. Installing the Outdoor Unit

Step 1 – Location Matters

Choose a flat, stable base—concrete pad, wall-mounted bracket, or solid pavers—ensuring at least:

• 12 inches of clearance behind

• 24 inches in front

• 5 ft from obstructions above

Avoid areas prone to flooding, snow buildup, or roof runoff.

Step 2 – Set the Condenser

Lift carefully (it’s ~80 lbs) and secure it to the pad or bracket using anti-vibration pads if possible.

(How To Install a Mini-Split Air Conditioner — thisoldhouse.com)

---

🔌 5. Routing and Connecting the Line Set

The MRCOOL Easy Pro’s Quick-Connect line set is what makes this DIY-friendly. No vacuum pump or refrigerant handling required!

Step 1 – Bundle Your Lines

Tape together:

• Suction (line A)

• Liquid (line B)

• Drain hose

• Electrical cable

Feed them gently through the wall sleeve to the outside.

Step 2 – Attach Indoor Connections

Inside, connect the lines to the indoor unit’s service valves (color-coded). Tighten to manufacturer torque specs using an adjustable wrench.

Step 3 – Connect Outdoor Lines

Outside, uncoil the line set carefully—never kink it. Connect each pre-charged fitting until you hear a distinct hiss, indicating refrigerant release. Continue tightening until snug.

Step 4 – Secure and Insulate

Wrap the bundle in UV-rated insulation or a decorative line-set cover kit. Secure against the wall to prevent vibration or damage.

(MRCOOL Installation Manual PDF — mrcool.com)

---

⚡ 6. Electrical Connection & Power Up

Check Local Code

Depending on your location, electrical codes may require a disconnect box or a specific wire gauge. A 12 k BTU MRCOOL unit generally runs on a 115 V / 15 A circuit, but confirm with your manual or local inspector.

Step 1 – Run Power to Disconnect

From your breaker panel, run a dedicated circuit to an outdoor disconnect near the condenser.

Step 2 – Connect Outdoor Power

Attach the line, neutral, and ground wires as labeled.

Step 3 – Link Indoor to Outdoor Units

The Easy Pro uses a pre-wired harness—simply match numbers or color codes (1-2-3-Ground) on both ends.

Step 4 – Double-Check

Before energizing, tug each connection lightly to confirm tightness.

Samantha’s Tip #3:

If you’re nervous about electricity, turn off your main breaker and take your time. No rush. Confidence beats speed.

---

💨 7. Condensate Drain Setup

Route the included drain hose downward from the indoor unit through the wall sleeve and out with the line set.

• Maintain a continuous downward slope.

• Secure it to prevent kinks.

• End it at a safe exterior drain point or condensate pump.

A blocked drain can cause water leaks inside, so test it with a cup of water poured into the indoor drain pan before finalizing.

---

📲 8. Final Steps — Startup & Testing

Step 1 – Check Connections

Ensure:

• Line sets are tight

• Power is secure

• Drain line slopes properly

• Outdoor condenser is level

Step 2 – Power On

Turn on the breaker and press the “Power” button on the remote. You’ll hear relays click and fans start within 1–2 minutes.

Step 3 – Mode Testing

Run Cool mode and Heat mode for 15 minutes each. Check airflow, condensate drainage, and outdoor fan rotation.

Step 4 – Wi-Fi Setup

Use the MRCOOL app to connect your unit for remote control, scheduling, and energy monitoring.

---

🪛 9. Samantha’s Troubleshooting Mini-Checklist

Most of these are quick DIY fixes—one of the joys of an accessible system.

---

🔧 10. My Real-World Lessons & Takeaways

1. Measure twice, drill once. The template helps, but checking alignment twice prevents regret.

2. Label everything. That tiny cable mix-up cost me half an hour.

3. Keep the line set gently. Avoid sharp bends; refrigerant lines hate kinks.

4. Seal the hole well. A little foam sealant stops drafts and pests.

5. Take your time. I finished in about 4 hours—including lunch and coffee breaks.

Now, my living space stays at the perfect temperature, my electric bill has dipped, and I have that special satisfaction every DIYer knows: “I installed that myself.”

---

🏁 Wrapping Up

Installing a ductless mini-split used to be something you’d hire out. The MRCOOL DIY Mini-Split Easy Pro Series 12,000 BTU Wall Mounted Ductless Heat Pump System changes that narrative. With its pre-charged line set, intuitive design, and homeowner-friendly manual, it truly earns the “DIY” in its name.

If you can hang a heavy picture frame, run a drill, and follow directions carefully, you can absolutely complete this installation.

So grab your tools, mark your wall, and get ready for the quiet hum of comfort—installed by you.

In the next blog, you will know "How Efficient Is the Easy Pro Series?".