MRCOOL® DIY® 5th Gen 2-Zone 18,000 BTU Ductless Mini Split Air Conditioner & Heat Pump with Pre-Charged (25ft+35ft) Line Sets & (9K+9K) Air Handlers— DIYM218HPW03D07

Product Description 
MRCOOL® DIY® 5th Gen 18,000 BTU 2-Zone Mini Split System – 23.9 SEER2 – Dual 9K Air Handlers – DIYM218HPW03D07
Product Overview
The MRCOOL® DIYM218HPW03D07 is a high-efficiency 18,000 BTU 2-zone ductless mini split system designed for homeowners who want professional-level heating and cooling performance without paying expensive HVAC installation costs. Built around the advanced MRCOOL® DIY® 5th Generation Multi-Zone platform, this system combines powerful energy-efficient comfort, true DIY installation, smart home compatibility, and year-round performance into one complete heating and cooling solution.
This bundle includes the MRCOOL® DIY-MULTI3-18HP230D-O outdoor condenser paired with two 9,000 BTU wall-mounted air handlers, making it ideal for heating and cooling two separate rooms up to 400 square feet each. It’s a perfect solution for bedrooms, home offices, garages, workshops, additions, apartments, upstairs living spaces, tiny homes, barndominiums, and older homes where traditional ductwork is difficult or expensive to install.
Unlike traditional mini split systems that require certified HVAC technicians, refrigerant charging, vacuum pumps, and specialty tools, the MRCOOL® DIY® system is engineered specifically for homeowner installation. The included QuickConnect® pre-charged line sets come factory-filled with refrigerant and are ready to connect right out of the box, making installation faster, easier, and more affordable.
This particular bundle includes both a 25-foot and 35-foot QuickConnect® line set, giving homeowners added installation flexibility for rooms farther away from the outdoor condenser.
Powered by inverter-driven compressor technology and eco-friendly R-454B refrigerant, this system delivers outstanding efficiency ratings up to 23.9 SEER2 while helping lower monthly utility bills. The variable-speed compressor automatically adjusts performance based on indoor demand for quieter operation, more stable temperatures, and improved energy savings.
The system also includes built-in smart home functionality through the MRCOOL® SmartHVAC app, Amazon Alexa, and Google Assistant compatibility, allowing you to control temperatures, schedules, and modes directly from your smartphone or voice assistant.
Whether you are upgrading an older HVAC system, adding comfort to multiple rooms, or building a new space without ductwork, the MRCOOL® DIY® 5th Gen Multi-Zone system delivers reliable comfort with true do-it-yourself simplicity.
 
What’s Included In This Bundle
Outdoor Condenser

MRCOOL® DIY-MULTI3-18HP230D-O
18,000 BTU Multi-Zone DIY® 5th Gen Condenser
208/230V

Indoor Air Handlers

(2) MRCOOL® DIY-09-HP-WMAH-230D25-O
9,000 BTU Wall Mounted Air Handlers
Up to 400 sq. ft. coverage each

Included Installation Components

(1) 25 ft QuickConnect® Pre-Charged Line Set- MC25-1438
(1) 35 ft QuickConnect® Pre-Charged Line Set- MC35-1438
DIYPRO® communication cable
(2) Wireless remote controls
(2) WiFi adapters
(2) Wall sleeves
Installation hardware and mounting accessories

Smartphone not included
 
Why Homeowners Choose MRCOOL® DIY®
True DIY Installation
No vacuum pump, gauges, refrigerant handling, or expensive HVAC labor required. The pre-charged QuickConnect® line sets simplify installation for homeowners using standard hand tools.
Independent Room Temperature Control
Each room operates independently, allowing personalized comfort while reducing wasted energy.
Outstanding Energy Efficiency
With up to 23.9 SEER2 efficiency and inverter compressor technology, this system helps reduce heating and cooling costs year-round.
Reliable Heating In Cold Weather
Designed for low ambient performance with reliable heating operation down to -13°F outdoor temperatures and strong heating capacity even around 5°F.
Smart Home Ready
Control your system from anywhere with:

MRCOOL® SmartHVAC App
Amazon Alexa
Google Assistant

Environmentally Friendly Refrigerant
Uses next-generation R-454B refrigerant with lower global warming potential compared to older refrigerants.
Quiet Indoor Comfort
Wall-mounted air handlers operate quietly, making them ideal for bedrooms, offices, and living spaces.
 
System Specifications
System Overview

Model Number: DIYM218HPW03D07
System Type: Ductless Mini Split Heat Pump
Zones: 2
Total Capacity: 18,000 BTU
Zone Configuration: 9K + 9K
Total Coverage Area: Up to 800 sq. ft.
Refrigerant Type: R-454B
Installation Type: DIY QuickConnect®
Voltage: 208/230V Single Phase

 
Outdoor Condenser Specifications
MRCOOL® DIY-MULTI3-18HP230D-O

Cooling Capacity: 18,000 BTU
Heating Capacity: 18,000 BTU
Cooling Efficiency: 23.9 SEER2
EER2: 13.0
Heating Efficiency: 10.0 HSPF2-4
HSPF2-5: 7.8
Outdoor Sound Level: 60 dB(A)
Cooling Operating Range: -13°F to 122°F
Heating Operating Range: -13°F to 75°F
Minimum Circuit Ampacity: 16A
Maximum Breaker Size: 20A
Dimensions: 35.04” W x 13.46” D x 26.50” H
Weight: 101.63 lbs

 
Indoor Air Handler Specifications
MRCOOL® DIY-09-HP-WMAH-230D25-O

Cooling Capacity: 9,000 BTU
Heating Capacity: 9,000 BTU
Coverage Area: 150–400 sq. ft.
Mount Type: Wall Mounted
Liquid Line Size: 1/4”
Suction Line Size: 3/8”
Dimensions: 31.57” W x 7.44” D x 11.69” H
Weight: 24.47 lbs

 
 Frequently Asked Questions on the MRCOOL® DIY® 5th Gen 18,000 BTU 2-Zone Mini Split System – 23.9 SEER2 – Dual 9K Air Handlers – DIYM218HPW03D07
What’s new with the MRCOOL® DIY® 5th Generation systems?
The 5th Gen MRCOOL® DIY® systems include several major upgrades over previous generations:

Eco-friendly R-454B refrigerant
Higher SEER2 energy efficiency
Improved cold weather performance
Enhanced inverter technology
Better overall reliability and durability

 
Can I install this system myself?
Yes. MRCOOL® DIY® systems are specifically designed for homeowners using QuickConnect® pre-charged line sets that eliminate the need for vacuum pumps or refrigerant charging.
A licensed electrician is recommended for final electrical hookup and code compliance.
 
Does this system work in cold weather?
Yes. The system is designed for low ambient heating performance and can continue heating in outdoor temperatures down to -13°F.
 
Does it provide both heating and cooling?
Yes. This is a heat pump system that provides both air conditioning and heating for year-round comfort.
 
Is WiFi included?
Yes. The system supports smart control through the MRCOOL® SmartHVAC app and works with Amazon Alexa and Google Assistant. As long as you have WiFi
 
What rooms work best with this system?
Perfect applications include:

Bedrooms
Home offices
Garages
Workshops
Tiny homes
Barndominiums
Apartments
Older homes without ductwork
Additions and bonus rooms

 
Warranty Coverage
The MRCOOL® DIY® 5th Generation system includes:

7-Year Compressor Replacement Warranty
5-Year Parts Warranty
Eligible for MRCOOL® Care registration

Warranty registration and annual MRCOOL® Care enrollment.
 
Why Buy From MRCOOL Direct?
MRCOOL Direct is one of America’s most trusted authorized MRCOOL dealers, providing genuine factory-direct equipment backed by real customer support.
When You Buy From Us, You Get:

Authorized MRCOOL dealer protection
Factory-fresh equipment
Full manufacturer warranty support
Fast nationwide shipping
Real product experts
Help with sizing and accessories
DIY installation guidance
No unauthorized marketplace sellers
Family-owned customer service you can trust

We proudly help homeowners across the USA save money with high-efficiency heating and cooling systems.
Need Help Choosing The Right System?
Call our HVAC specialists anytime:
615-553-8118
Friendly support from real people who love talking HVAC.
BUY DIRECT FROM MRCOOL DIRECT
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