What's in the box
- MRCOOL® 18K DIY® 5th Gen 3-Zone Mini-Split Condenser
- DIYPro™ Communication Cable
- Wireless Remote Control
- Installation Accessories
- MRCOOL® Warranty
- Free U.S. curbside delivery within the Lower 48 States on qualifying orders
- Orders ship from U.S. warehouses
- Delivery times may vary by location and carrier availability
- Returns accepted within 30 days for unused and uninstalled products
- Approved returns may be subject to a restocking fee
MODEL: DIY-MULTI3-18HP230D-O
DIY Multi-Zone Climate Control for Up to 3 Rooms (750 sq. ft.)
Take total control of your home’s comfort with the MRCOOL® 18K DIY® 5th Generation Multi-Zone Mini-Split Condenser — a high-performance, energy-efficient system designed for reliable heating and cooling across up to three separate rooms. Perfect for homes, apartments, basements, garages, or offices totaling up to 750 sq. ft.
Delivering a top-tier SEER2 rating of 23.9 and HSPF2-4 of 10, this 1.5-ton condenser offers outstanding efficiency and year-round savings. The game-changing Quick Connect® pre-charged line sets — now filled with eco-conscious R-454B refrigerant — allow for fast, clean, and fully DIY-friendly installation with no vacuuming, gauges, or professional assistance required.
Pair it with up to 3 MRCOOL® 5th Gen DIY® Air Handlers to personalize each room’s climate to your exact preference. Integrated Wi-Fi control via the SmartHVAC® app, Amazon Alexa, and Google Assistant lets you manage schedules, modes, and temperature settings remotely — or by voice command.
Engineered with durable, weather-resistant components and a quiet, efficient rotary inverter compressor, this unit ensures long-lasting, whisper-quiet operation at just 60 dBA. It’s backed by an exceptional Limited Lifetime Compressor Replacement Warranty (with registration), giving you total confidence in your investment.
Why You’ll Love It
✅ Controls Up to 3 Zones — Connects to three air handlers for flexible, multi-room heating and cooling.
✅ Seamless DIY Installation — Use MRCOOL® Quick Connect® pre-charged line sets for a no-vacuum, tool-free setup.
✅ Top Energy Efficiency — SEER2 23.9 and HSPF2-4 10 for lower energy bills and eco-friendly performance.
✅ Smart-Home Compatible — Control your system via the SmartHVAC® app, Alexa, and Google Assistant.
✅ Follow Me® Technology — Tracks temperature where you are, not just where the unit is.
✅ Ultra-Quiet, Reliable Operation — Rotary inverter compressor for low-noise, efficient comfort (60 dBA).
✅ Built-In Future-Ready Design — Features durable components and eco-conscious R-454B refrigerant.
✅ Industry-Leading Warranty — Limited Lifetime Compressor (with registration), 7-Year Compressor, and 5-Year Parts Warranty.
What You Need for a Complete System
For full operation and optimal performance, pair this condenser with:
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MRCOOL® DIY® 5th Gen Multi-Zone Air Handlers (up to 3 total)
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MRCOOL® Quick Connect® Pre-Charged Line Sets (available in multiple lengths — sold separately)
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DIYPro™ Communication Cables (25ft included with each air handler)
Optional Accessories:
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MRCOOL® Wall Mount Bracket
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Additional Quick Connect® Line Sets
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Coupler Kits (for line set extensions)
| BTU Capacity | 18,000 BTU |
| Voltage | 208/230V |
| Zones Supported | Up to 3 |
| SEER2 | 23.9 |
| HSPF2-4 / HSPF2-5 | 10 / 7.8 |
| Refrigerant Type | R-454B |
| Line Set Compatibility | MRCOOL® Quick Connect® |
| Max Line Set Length (ft) | 172.2 |
| Liquid Line Size | 1/4″ |
| Suction Line Size | 3/8″ |
| Sound Rating (dBA) | 60 |
| Wi-Fi Compatibility | Yes (SmartHVAC App, Alexa, Google Assistant) |
| Warranty | Limited Lifetime Compressor (registered), 7-Year Compressor, 5-Year Parts |
Questions, answered
Everything homeowners ask before buying a MRCOOL® system.
Installation
What installation requirements apply to this product?
Installation requirements vary by product type. Selected complete MRCOOL® DIY systems are designed for homeowner installation when fitted in line with the manufacturer’s instructions, local codes and permit requirements.
Central HVAC systems, including Universal®, VersaPro®, Central Ducted Hyper Heat and packaged systems, are intended for professional installation by a qualified HVAC contractor. Licensed electrical work may also be required.
Components, thermostats, controls, line sets and accessories should be installed according to their product documentation and compatibility requirements. Always review the product page, manufacturer guidance and warranty conditions before installation.
Will I need any additional parts, tools or professional services?
Additional requirements vary by product and installation. Tools, electrical materials, mounting hardware, connecting components or other installation supplies may be required unless specifically stated as included.
Review the product description, specifications, installation information and What’s Included section, where available, before ordering.
Where can I find product documents or installation instructions?
Available specifications, installation instructions, owner’s manuals and manufacturer documents are provided on the product page where applicable.
Some simple accessories may not have a separate installation manual. Contact our team if you need help locating documentation for a particular product or model.
Sizing & Compatibility
How do I confirm this product is compatible with my equipment?
Review the product type, model number, dimensions, voltage, capacity, refrigerant type, connection sizes and compatibility information shown on the product page, where applicable.
Components, thermostats, controls and accessories must be matched to compatible equipment. Contact our team before ordering if you are uncertain about compatibility.
What should I check before ordering?
Confirm the product name and model number, together with any relevant dimensions, voltage, capacity, refrigerant type, connections and installation requirements.
For replacement components and accessories, compare the product specifications with your existing equipment and the relevant manufacturer documentation before placing your order.
What is included with this product?
The supplied items are listed in the What’s Included section or product description, where applicable. Only the products, components and accessories specifically stated are included.
Electrical materials, mounting equipment, connecting components or other installation supplies may need to be purchased separately unless expressly stated otherwise.
Warranty & Support
What warranty coverage applies to this product?
Warranty coverage varies by product and model. Eligible MRCOOL® products are covered according to the manufacturer’s warranty terms, registration requirements and installation conditions.
Accessories and individual components may have different coverage. Cool Heat Direct can provide available warranty documentation and general guidance, while warranty eligibility and claim decisions are determined by the manufacturer.
How can I get help before ordering?
Email support@coolheatdirect.com with the product name or model number and details about your project or existing equipment.
For compatibility questions, include the model numbers of any products you intend to connect, control, replace or use together.
Support hours: Monday–Friday, 9 AM–6 PM ET.
Shipping & Returns
How will my order be shipped?
Free standard shipping is available on eligible orders to the Lower 48 states and Washington, D.C.
Orders are generally processed within 3–5 business days, followed by approximately 5–12 business days in transit. Delivery timing varies by product availability, destination and carrier scheduling.
Smaller products may ship by parcel carrier. Larger equipment may be delivered curbside by freight carrier. The carrier may contact you to arrange a delivery appointment.
Can I return this product?
Return requests may be submitted within 30 calendar days of delivery. Products must be new, unused and uninstalled and, where applicable, unpowered. They must also be complete and in their original manufacturer packaging. Prior written authorization is required.
For approved change-of-mind returns, incorrect sizing or customer ordering errors, the customer is responsible for return freight and a 15% restocking fee applies.
Verified damaged, defective, incorrect or incomplete orders are handled separately under our full policy.
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