Must-Have｜MRCOOL® 27k 5th Gen 4-Zone DIY® Multi-Zone Mini Split Bundle (9k + 18k) Air Handlers (25ft + 25ft) Pre Charged Line Sets, R-454B, (230V) — DIYM227HPW03D07

Product Description 
MRCOOL® DIY® 5th Gen 27,000 BTU 2-Zone Mini Split System – 23 SEER2 – 9K + 18K Air Handlers – DIYM227HPW03D07
Product Overview
The MRCOOL® DIYM227HPW03D07 is a high-efficiency 27,000 BTU 2-zone ductless mini split heat pump system designed for homeowners who want powerful room-by-room comfort without paying expensive professional HVAC installation costs. Built around the MRCOOL® DIY® 5th Generation Multi-Zone platform, this bundle delivers smart heating, cooling, dehumidification, and independent temperature control for two different spaces from one outdoor condenser.
This complete system pairs the MRCOOL® DIY-MULTI4-27HP230D-O 27K class 4-zone condenser with one 9,000 BTU wall-mounted air handler and one 18,000 BTU wall-mounted air handler. It is an excellent choice when you need comfort in one medium-sized room and one larger space. The 9K air handler is ideal for bedrooms, home offices, nurseries, guest rooms, small living rooms, or rooms up to 400 square feet. The 18K air handler is built for larger areas up to 800 square feet, including master bedrooms, open living areas, garages, workshops, finished basements, bonus rooms, studios, ADUs, and apartment spaces.
Unlike traditional mini split systems that require vacuum pumps, gauges, refrigerant charging, and costly HVAC labor, the MRCOOL® DIY® system is engineered for homeowner installation. The included DIY® QuickConnect® pre-charged line sets arrive factory-sealed with R-454B refrigerant already inside, making installation faster, cleaner, and easier. No vacuuming. No refrigerant handling. No special HVAC tools required for the line set connection.
This bundle includes two 25 ft QuickConnect® line sets, giving you more flexibility when indoor units are farther from the outdoor condenser. The 9K air handler uses the DIY25-1438-O 25 ft line set, and the 18K air handler uses the DIY25-1412-O 25 ft line set.
With up to 23 SEER2 cooling efficiency, 9.5 HSPF2-4 heating performance, inverter-driven compressor technology, and next-generation R-454B refrigerant, this system is built for reliable year-round comfort while helping reduce monthly utility costs. The inverter compressor adjusts output based on demand, which helps improve temperature stability, reduce energy waste, and keep operation quieter than many older HVAC systems.
Smart comfort is built in. Use the included wireless remotes, the MRCOOL® SmartHVAC app, Amazon Alexa, or Google Assistant to adjust temperatures, schedules, fan speeds, and operating modes from virtually anywhere.
This condenser supports up to 4 indoor zones total, and this bundle uses 2 zones, leaving two additional ports available for future expansion with compatible MRCOOL® DIY indoor units.
If you want a true DIY mini split system for a bedroom and living room, office and garage, workshop and apartment, or two different-sized spaces, the MRCOOL® DIYM227HPW03D07 gives you professional-grade comfort, flexible zoning, and homeowner-friendly installation in one complete package.
 
What’s Included In This Bundle
Outdoor Condenser

MRCOOL® DIY-MULTI4-27HP230D-O
27,000 BTU class DIY® 5th Gen Multi-Zone Condenser
Supports up to 4 indoor zones
208/230V

Indoor Air Handlers

MRCOOL® DIY-09-HP-WMAH-230D25-O

9,000 BTU Wall Mounted Air Handler
Covers up to 400 sq. ft.

MRCOOL® DIY-18-HP-WMAH-230D25-O

18,000 BTU Wall Mounted Air Handler
Covers up to 800 sq. ft.

Included Line Sets

DIY25-1438-O

25 ft DIY® QuickConnect® Pre-Charged Line Set
1/4” x 3/8”
For the 9K air handler

DIY25-1412-O

25 ft DIY® QuickConnect® Pre-Charged Line Set
1/4” x 1/2”
For the 18K air handler

Included Accessories

DIYPRO® communication cable
Wireless remotes for each indoor unit
SmartHVAC WiFi/app capability
Wall mounting hardware
Installation accessories and manuals

Smartphone not included
 
Ideal Room Applications
This MRCOOL® DIY® 27K 2-zone mini split bundle is ideal for:

Bedroom + living room
Home office + garage
Nursery + master bedroom
Workshop + apartment space
Finished basement + upstairs room
Bonus room + studio
ADU or in-law suite
Airbnb or rental unit
Older homes without ductwork
Home additions and remodels
Small retail or professional suites

Estimated coverage:

9K Zone: up to 400 sq. ft.
18K Zone: up to 800 sq. ft.
Total estimated coverage: up to 1,200 sq. ft.

Actual coverage may vary based on insulation, ceiling height, climate, windows, sun exposure, and room layout.
 
Why Homeowners Choose MRCOOL® DIY®
True DIY® Installation
The MRCOOL® DIY® system is designed for homeowner installation using pre-charged QuickConnect® line sets. No vacuum pump, gauges, or refrigerant charging is required for the line set connection.
Independent 2-Zone Comfort
Each indoor air handler controls its own room, allowing personalized comfort and less wasted energy.
Expandable 4-Zone Platform
This bundle uses 2 zones, but the outdoor condenser supports up to 4 indoor units total. Add more compatible indoor units later if your comfort needs grow.
High-Efficiency Heating & Cooling
With inverter compressor technology and up to 23 SEER2 efficiency, this system helps lower energy use while maintaining steady indoor comfort.
Built For Year-Round Comfort
Provides cooling, heating, dehumidification, fan-only operation, auto mode, sleep mode, and quiet operation for all-season comfort.
Smart Home Ready
Control your system using:

MRCOOL® SmartHVAC App
Amazon Alexa
Google Assistant
Included wireless remotes

R-454B Refrigerant
Uses next-generation R-454B refrigerant designed for improved environmental performance while maintaining strong heating and cooling operation.
Gold Fin® Protection
Gold Fin® corrosion-resistant coating helps improve long-term durability in humid, coastal, and harsh outdoor environments.
Follow Me® Temperature Sensing
The included remote can sense the temperature near you, helping the system adjust comfort based on where you are in the room.
 
System Specifications
System Overview

Model Number: DIYM227HPW03D07
System Type: Ductless Mini Split Heat Pump
Zones Included: 2
Zones Supported By Condenser: Up to 4
Outdoor Condenser Class: 27,000 BTU
Indoor Configuration: 9K + 18K
Estimated Total Coverage: Up to 1,200 sq. ft.
Refrigerant: R-454B
Included Line Sets: (1) 25 ft 1/4” x 3/8” + (1) 25 ft 1/4” x 1/2”
Voltage: 208/230V
Phase: 1
Cycle: 60Hz
Installation Type: DIY® QuickConnect®

 
Outdoor Condenser Specifications
MRCOOL® DIY-MULTI4-27HP230D-O

Cooling Capacity: 26,000 BTU
Heating Capacity: 26,000 BTU
SEER2: 23
EER2: 12
HSPF2-4: 9.5
HSPF2-5: 7
Tonnage: 2.25 Ton
Compressor Type: DC Inverter Rotary
Outdoor Sound Level: 61 dB(A)
Cooling Operating Range: -13°F to 122°F
Heating Operating Range: -13°F to 75°F
Minimum Circuit Ampacity: 23A
Maximum Fuse Breaker: 25A
Maximum Total Line Length: 221.4 ft
ENERGY STAR® Certified: Yes
AHRI Certified: Yes
UL Listed: Yes
ETL Listed: Yes
Net Dimensions: 37.24” W x 31.89” H x 16.14” D
Net Weight: 140.21 lbs

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

Quantity Included: 1
Cooling Capacity: 9,000 BTU
Heating Capacity: 9,000 BTU
Coverage Area: Up to 400 sq. ft.
Mount Type: Wall Mount
Voltage: 208/230V
Filter Type: Reusable
Liquid Line Size: 1/4”
Suction Line Size: 3/8”
Net Dimensions: 31.57” W x 11.69” H x 7.44” D
Net Weight: 24.47 lbs

Operating Modes

Cool
Heat
Auto
Fan
Dry / Dehumidification
Sleep
Quiet Mode

 
MRCOOL® DIY-18-HP-WMAH-230D25-O

Quantity Included: 1
Cooling Capacity: 18,000 BTU
Heating Capacity: 18,000 BTU
Coverage Area: Up to 800 sq. ft.
Mount Type: Wall Mount
Voltage: 208/230V
Indoor Sound Range: 19–54.5 dB(A)
Liquid Line Size: 1/4”
Suction Line Size: 1/2”
Net Dimensions: 42.52” W x 13.19” H x 8.9” D
Net Weight: 35.49 lbs

Operating Modes

Cool
Heat
Auto
Fan
Dry / Dehumidification
Sleep
Quiet Mode

 
Frequently Asked Questions about the MRCOOL® DIY® 5th Gen 27,000 BTU 2-Zone Mini Split System – 23 SEER2 – 9K + 18K Air Handlers – DIYM227HPW03D07
Can I install this system myself?
Yes. MRCOOL® DIY® systems are built for homeowner installation using pre-charged QuickConnect® line sets. No vacuum pump, gauges, or refrigerant charging is required for the line set connection.
A licensed electrician should complete the electrical hookup to meet local code requirements.
How many rooms can this system heat and cool?
This bundle includes 2 indoor air handlers for 2 separate rooms. The outdoor condenser supports up to 4 indoor zones total for future expansion.
Can I add more indoor units later?
Yes. This condenser supports up to 4 zones. Since this bundle uses 2 zones, two additional compatible indoor units may be added later as long as the total connected capacity stays within MRCOOL® guidelines.
What room sizes does this bundle cover?
The 9K air handler is ideal for rooms up to 400 sq. ft. The 18K air handler is ideal for rooms up to 800 sq. ft.
Are the line sets pre-charged?
Yes. This bundle includes one DIY25-1438-O 25 ft pre-charged line set and one DIY25-1412-O 25 ft pre-charged line set.
Does this system heat and cool?
Yes. This is a ductless heat pump system designed for both air conditioning and heating.
Is this system smart-home compatible?
Yes. The system works with the MRCOOL® SmartHVAC app, Amazon Alexa, and Google Assistant.
What breaker size does this condenser need?
The DIY-MULTI4-27HP230D-O condenser lists a maximum fuse/breaker of 25A and a minimum circuit ampacity of 23A. Always follow local electrical code and consult a licensed electrician.
What warranty comes with this system?
This MRCOOL® DIY® 5th Gen system includes:

5-Year Parts Warranty
7-Year Compressor Warranty

Eligible for the MRCOOL® Care Kit program registration.
 
Why Buy From MRCOOL Direct?
When you order from MRCOOL Direct, you get genuine MRCOOL® equipment, real product support, and a warranty-safe buying experience from an authorized MRCOOL dealer.
Why Customers Choose Us

Authorized MRCOOL dealer protection
Factory-fresh equipment
Fast U.S. shipping on in-stock products
Financing options available
Help with sizing and layout
Line set and accessory guidance
DIY installation support
No third-party marketplace confusion
Friendly family-owned support

Need help choosing the right system or confirming line set lengths?
Call MRCOOL Direct:
615-553-8118
We love helping customers find the right HVAC setup.
BUY DIRECT FROM MRCOOL DIRECT
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