Member Exclusive｜MRCOOL® DIY® 5th Gen 2-Zone 18,000 BTU Ductless Mini Split Air Conditioner & Heat Pump with Pre-Charged (25ft+25ft) Line Sets (9K+9K) Air Handler — DIYM218HPW03D06

Product Description
MRCOOL® DIY® 5th Gen 18,000 BTU 2-Zone Mini Split System – 23.9 SEER2 – Dual 9K Air Handlers – R-454B
Product Overview
The MRCOOL® DIY® 5th Generation Multi-Zone Mini Split System is one of the easiest and most energy-efficient ways to heat and cool multiple rooms without expensive HVAC installation costs. Designed specifically for homeowners, this high-performance 18,000 BTU 2-zone ductless mini split system delivers year-round comfort, smart home convenience, and powerful energy savings — all while being truly DIY-friendly.
This complete MRCOOL® multi-zone system includes one 18,000 BTU outdoor condenser and two 9,000 BTU wall-mounted air handlers, making it ideal for cooling and heating two separate rooms up to 400 square feet each. Whether you’re upgrading bedrooms, home offices, garages, additions, apartments, workshops, tiny homes, or older homes without ductwork, this system gives you independent temperature control in each room for personalized comfort.
Unlike traditional HVAC systems that require professional installation, vacuum pumps, refrigerant charging, and costly labor, the MRCOOL® DIY® system uses patented QuickConnect® pre-charged line sets that come ready to install right out of the box. No special HVAC tools or refrigerant handling is required.
Built around the newest MRCOOL® DIY® 5th Gen technology platform, this system now uses eco-friendly R-454B refrigerant for improved environmental performance while maintaining powerful heating and cooling efficiency. With up to 23.9 SEER2 efficiency ratings and inverter-driven compressor technology, this system helps reduce energy usage while keeping temperatures consistent year-round.
The system also comes equipped with smart WiFi control compatibility through the MRCOOL® SmartHVAC app, Amazon Alexa, and Google Assistant, allowing you to control your comfort from virtually anywhere.
If you want professional-level comfort without paying professional installation prices, the MRCOOL® DIY® 5th Gen system is one of the best ductless mini split solutions available today.
 
What’s Included
Outdoor Condenser

MRCOOL® DIY-MULTI3-18HP230D-O
18,000 BTU Multi-Zone 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

Installation Components

(2) 25ft Pre-Charged QuickConnect® Line Sets DIY25-1438
DIYPRO® communication cable
(2) Wireless remote controls
(2) WiFi adapters
(2) Wall sleeves
Mounting hardware & installation accessories

Smartphone not included
 
Why Homeowners Choose MRCOOL® DIY®
True DIY Installation
No vacuum pump. No gauges. No refrigerant handling. No expensive HVAC labor costs.
The included QuickConnect® pre-charged line sets make installation dramatically easier than traditional mini split systems.
Independent Room Control
Each room gets its own air handler and separate temperature control, improving comfort and reducing wasted energy.
High-Efficiency Heating & Cooling
With up to 23.9 SEER2 efficiency and inverter technology, this system helps lower monthly utility bills while maintaining consistent indoor temperatures.
Reliable Cold Weather Heating
Designed for year-round comfort with low ambient heating performance down to -13°F outdoor temperatures.
Smart Home Ready
Built-in WiFi compatibility works with:

MRCOOL® SmartHVAC App
Amazon Alexa
Google Assistant

Eco-Friendly R-454B Refrigerant
Uses next-generation refrigerant with lower environmental impact and compliance with new HVAC efficiency standards.
Quiet Operation
Indoor air handlers operate quietly, making them perfect for bedrooms, offices, and living spaces.
 
System Specifications
System Overview

System Type: Ductless Mini Split Heat Pump
Zones: 2
Total Capacity: 18,000 BTU
Zone Capacity: 9,000 BTU + 9,000 BTU
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
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: Up to 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 – Bundle DIYM218HPW03D06 Dual 9K Air Handlers – Dual Pre-Charged line set, R-454B
What’s new with the MRCOOL® DIY® 5th Gen systems?
The 5th Generation MRCOOL® DIY® systems include several major upgrades over previous generations, including:

New eco-friendly R-454B refrigerant
Higher energy efficiency ratings
Improved cold weather performance
Enhanced reliability and durability
Updated inverter technology

 
Can I install this system myself?
Yes. This is a true DIY® mini split system designed specifically for homeowners. The pre-charged QuickConnect® line sets eliminate the need for HVAC gauges or refrigerant charging.
A licensed electrician is recommended for the final electrical connection.
 
Does this system heat as well as cool?
Yes. This is a heat pump system that provides both air conditioning and heating for year-round comfort.
 
Will this work in cold weather?
Yes. The MRCOOL® DIY® 5th Gen system is designed for low ambient heating and can continue heating in outdoor temperatures down to -13°F.
 
Is WiFi included?
Yes. The system supports WiFi connectivity through the MRCOOL® SmartHVAC app and works with Amazon Alexa and Google Assistant. As long as you have WiFi.
 
What rooms is this system best for?
Perfect applications include:

Bedrooms
Home offices
Garages
Workshops
Tiny homes
Barndominiums
Apartments
Older homes without ductwork
New additions
Basement finishing projects

 
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 MRCOOL dealers, providing genuine factory-authorized equipment with real customer support before and after the sale.
When You Buy From Us, You Get:

Authorized MRCOOL dealer protection
Factory-fresh equipment
Full manufacturer warranty support
Fast nationwide shipping
Expert sizing assistance
Help choosing line sets and accessories
DIY installation support
No unauthorized marketplace sellers
Real customer service from real people

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 product specialists anytime:
615-553-8118
Friendly support from a family-owned company that truly cares about its customers.
BUY DIRECT FROM MRCOOL DIRECT
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