MRCOOL® DIY® 5th Gen 2-Zone 18,000 BTU Ductless Mini Split Air Conditioner & Heat Pump with (16ft+16ft) Pre-Charged Line Sets (9K+9K) Air-handlers- R-454B- DIYM218HPW03D0

Product Description 
Model DIYM218HPW03D0
Take control of your comfort with the MRCOOL® DIY® 5th Gen Multi-Zone Mini Split System - the easiest and most affordable way to get powerful, energy-saving heating and cooling without hiring a pro.

Two Rooms, Perfect Comfort: Heat or cool two spaces up to 400 sq. ft. each with independent temperature control for personalized comfort.

Truly DIY-Friendly: Forget expensive installs - no HVAC license or special tools required. If you can use basic hand tools, you can do this.

No Hassle Setup: Comes with MRCOOL® DIY® pre-charged Quick-Connect® line sets, so there’s no messy refrigerant handling or vacuuming. Just connect and enjoy.

Year-Round Savings: Boasting up to 23.9 SEER2 cooling efficiency and 10.8 HSPF2-4 heating performance, this system delivers serious energy savings.

Built for Every Season: Stay cozy even in the dead of winter - reliable heating works all the way down to -13°F. 100% at 5 Degrees. 

Strong Warranty Protection: Includes 7-Year Compressor Replacement and 5-Year Parts Coverage.

(Smart Phone not included)

Whether it’s hot summer days or freezing winter nights, theMRCOOL® DIY® Mini Split keeps your home comfortable and your energy bills low. Smart. Simple. Affordable.
Why Choose MRCOOL DIY?

True DIY Installation – No special tools, training, or HVAC license required. The included pre-charged Quick Connect® line sets come filled with eco-friendly R-454B refrigerant, making installation fast and hassle-free.

Save Thousands on Installation – Skip the high labor costs of traditional systems by doing it yourself with easy step-by-step video instructions.

Year-Round Comfort – This heat pump design provides cooling in summer, heating in winter, and dehumidification during wet seasons.

Advanced Features

23.9 SEER2 Efficiency – Energy-saving inverter technology keeps comfort high and utility bills low.

Smart Controls – Operate your system with the MRCOOL Smart Controller app, Amazon Alexa, or Google Home. Each air handler also comes with a wireless remote.

Gold Fin® Condenser – Built for long-lasting durability, corrosion resistance, and reliable performance.

Follow Me® Function – Sensors in the remote adjust the temperature based on where you are in the room.

Low Ambient Cooling – Keeps working even in cold outdoor conditions.

Alerts & Self-Diagnostics – Easy-to-read digital display shows error codes, filter reminders, and refrigerant alerts for simple maintenance.

Quiet Comfort – Sleep mode saves energy overnight, while mute mode eliminates lights and alerts for undisturbed rest.

Auto Restart – System remembers your last settings and resumes automatically after a power outage.

What's Included
• 1 18k BTU Condenser 
• 2 9k BTU Air Handler
• 2 x 16ft  DIY® Quick Connect® Pre-Charged Line Sets
DIYPRO® Cable: Durable armored cable eliminates the need for electrical conduit
Air Handler Compatibility
This condenser supports up to three indoor air handlers with a maximum combined capacity of 24,000 BTU. Available air handler sizes: 6K, 9K, and 12K BTU.
Examples of Compatible Combinations:

6K + 6K + 12K (24,000 BTU)
6K + 9K + 9K (24,000 BTU)
6K + 6K + 9K (21,000 BTU)
6K + 9K + 6K (21,000 BTU)
9K + 9K (18,000 BTU – one port unused)

6K + 12K (18,000 BTU – one port unused)

Recommended Wire Sizing

Recommended: 12 AWG copper wire – safe for 18A minimum circuit ampacity

One Size Smaller (14 AWG): Not recommended – may overheat under full load and violate electrical code

One Size Larger (10 AWG): Offers lower voltage drop and extra safety margin

Ideal Coverage Area
Perfect for spaces ranging from 750 to 1,100 sq. ft., depending on your climate zone and insulation quality. With the 18k btu 1.5 Ton Condenser. 
SPECIFICATIONS & DIMENSIONS

SYSTEM OVERVIEW

System Type
Ductless Mini Split Air Conditioner & Heat Pump

Zones
2

Capacity
Total: 18,000 BTUZone 1: 9,000 BTUZone 2: 9,000 BTU

Coverage Area
Total: 800 sq. ft.Zone 1: 400 sq. ft.Zone 2:400 sq. ft.

Refrigerant
R-454B

Line Sets Included
2 x 16ft Pre-Charged Line Sets

Warranty
7 Years Compressor5 Years Parts

OUTDOOR UNIT (18K) x 1

Model
DIY-MULTI3-18HP230D-O

Dimensions
35.04" W x 13.46" D x 26.50" H

Cooling Capacity
18,000 BTU

SEER2
23.9

EER2
13.0

Heating Capacity
18,000 BTU

HSPF2-4
10.0

HSPF2-5
7.8

Outdoor Noise Level
60.0 dB(A)

Outdoor Operating Temperature
Cooling: -13°F – 122°FHeating: -13°F – 75°F

Voltage
208–230V

Phase
1

Cycle
60Hz

Min Circuit Ampacity
16.0A

Max Fuse Breaker
20.0A

Weight
101.63 lbs

INDOOR UNIT (9K) x 2

Model
DIY-09-HP-WMAH-230D25-O

Dimensions
31.57" W x 7.44" D x 11.69" H

Mounting Type
Wall

Cooling Capacity
9,000 BTU

Heating Capacity
9,000 BTU

Coverage Area
351 to 400 sq. ft.

Liquid Line Size
1/4"

Suction Line Size
3/8"

Weight
24.47 lbs

Frequently Asked Questions & Answers 
What's the difference between the 5th Gen and 4th Gen?
The 5th Gen MRCOOL® DIY® Mini Split offers several key upgrades over the 4th Gen, focusing on efficiency, advanced technology, and eco-friendliness.
Here’s what’s new with the 5th Gen:

Next-Gen R-454B Refrigerant: A more environmentally friendly refrigerant with lower global warming potential (GWP), compliant with the latest HVAC regulations.

Higher Energy Efficiency: Improved SEER2 ratings for greater energy savings and optimized performance.

Enhanced System Reliability: Upgraded components for better heating and cooling performance.

Can I install it myself, or do I need a professional?
The MRCOOL® DIY system is designed for homeowners and doesn’t require HVAC tools. You can install the indoor and outdoor units yourself using the pre-charged Quick Connect® lines. However, a licensed electrician is required for the electrical hookup to ensure safety and code compliance.
Does it work in cold weather?
Yes. MRCOOL® 5th Gen systems feature low-ambient heating and can provide reliable heat even when outdoor temperatures drop to around 5°F.
How do I know what BTU size I need for my rooms?
A general rule of thumb is 20 BTU per square foot of space. Here's a rough guide:

6,000 BTU = 100 - 200sq ft
9,000 BTU = 150 - 400sq ft
12,000 BTU = 351- 550 sq ft
18,000 BTU = 501 – 800 sq ft
24,000 BTU = 751 – 1,050 sq ft
36,000 BTU = 1,001 - 1,550 sq ft

Some additional factors may impact performance such as insulation, ceiling height, sun exposure and the number of appliances in the room. For assistance, contact our Product Experts.

Does it heat as well as cool?Yes. All 5th Gen models are heat pumps, providing both heating and cooling for year-round comfort.

Is it Wi-Fi compatible?
Yes. The MRCOOL® SmartHVAC app allows smartphone control and works with Amazon Alexa and Google Assistant.

What is the warranty?

The MRCOOL® 5th Generation DIY Mini-Split systems offer the following warranty coverage:

7-Year Compressor Replacement Warranty: This warranty ensures that if the compressor fails within the first seven years, MRCOOL® will provide a replacement.

5-Year Parts Warranty: This warranty covers all parts of the system for five years from the date of purchase. lifetime technical support from MRCOOL.

Note: Always verify system configuration before purchasing. Specifications may change during production. Images may be representative 
 
 
Whether it’s hot summer days or freezing winter nights, theMRCOOL® DIY® Mini Split keeps your home comfortable and your energy bills low. Smart. Simple. Affordable.
 
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