MRCOOL DIY® 5th Gen 2-Zone 18,000 BTU Mini-Split System 230V with Pre-Charged Line Sets – 9K+9K, Up to 700 Sq. Ft. | DIY-MULTI3-18HP230D-O

MRCOOL® DIY® 5th Gen 2-Zone 18,000 BTU Mini-Split System with Pre-Charged Line Sets – 9K+9K, 230V

The MRCOOL® DIY® 5th Gen 2-Zone 18,000 BTU System with Pre-Charged Line Sets is the complete, ready-to-install package for heating and cooling two rooms up to 350 sq. ft. each — 700 sq. ft. total — from a single outdoor condenser. Unlike the base bundle, this version includes two pre-charged QuickConnect® line sets in your choice of length combinations. Select the line set lengths that match your installation before adding to cart. With a 23.9 SEER2 rating, Energy Star certification, and MRCOOL’s best-in-class warranty, this is the most efficient and convenient 2-zone DIY mini split package available.

Why Choose MRCOOL DIY® 5th Gen 2-Zone with Line Sets?

• Line Sets Included — Two pre-charged QuickConnect® line sets are included in your chosen length combination. No separate purchase needed — just select your lengths above.
• Independent Zone Control — Each room has its own air handler and thermostat setting. One zone can be cooling while the other is heating simultaneously.
• 23.9 SEER2 — Premium Efficiency — One of the highest SEER2 ratings in the MRCOOL multi-zone lineup for maximum year-round energy savings.
• Energy Star Certified — May qualify for federal tax credits and utility rebates.
• One Outdoor Unit, Two Rooms — A single 18K condenser powers both zones, saving outdoor space and installation cost vs. two separate single-zone systems.
• True DIY Installation — No HVAC license required. Pre-charged line sets make installation vacuum-free.
• Operates to -13°F — Reliable heating even in cold climates.
• Gold Fin® Coil Protection — Superior corrosion resistance, ideal for coastal homes and harsh climates.
• Smart Connectivity — Control each zone via the SmartHVAC app (iOS & Android), or hands-free with Amazon Alexa or Google Assistant.
• Extended Warranty Available — Register your unit and enroll in the MRCOOL Care Program annually to qualify for extended lifetime compressor replacement coverage.
• Certified Excellence — Energy Star Certified, AHRI Certified, UL Listed, ETL Listed.

System Overview

• 🏠 Zones: 2
• 📐 Total Coverage: Up to 700 sq. ft. (350 sq. ft. per zone)
• 🔧 Installation: DIY — No Professional Required
• ⚡ Voltage: 208-230V
• 📦 Line Sets: Included — select your length combination above
• 🌿 Energy Star Certified — May qualify for federal tax credits & utility rebates
• 🧄 Refrigerant: R-454B

What’s in the Box

• ✅ 1x 18,000 BTU outdoor condenser (DIY-MULTI3-18HP230D-O)
• ✅ 2x 9,000 BTU wall-mount air handlers (DIY-09-HP-WMAH-230D25-O)
• ✅ 2x pre-charged QuickConnect® line sets in your selected lengths

Line Set Length Options

Select the combination that best matches the distance from your outdoor condenser to each indoor air handler. Measure before ordering — line sets cannot be shortened.

• 16 ft. + 16 ft.
• 16 ft. + 25 ft.
• 16 ft. + 35 ft.
• 25 ft. + 25 ft.
• 25 ft. + 35 ft.
• 35 ft. + 35 ft.
• 50 ft. + 50 ft.

Specifications & Dimensions

Shipping & Returns

🚚 Free Curbside Delivery
All MRCOOL orders ship free via FedEx Ground, FedEx Freight, or an equivalent trusted carrier. Delivery is curbside only — please arrange assistance in advance as carriers are not able to bring items inside your home.

Tracking & Delivery
Tracking information is typically provided within 3–5 business days of your order. Once received, please allow 1–2 business days for tracking details to update.

↩️ Return Policy

30-Day Return Window
Returns must be requested within 30 days of your delivery date. We are unable to accept return requests after this period.

Return Conditions
To qualify for a return, items must be unused and uninstalled, and in original packaging including box and pallet.

Restocking Fee
A 35% restocking fee applies to all approved returns.

📄 View Full Shipping Policy | 📄 View Full Return & Refund Policy

Frequently Asked Questions

What’s the difference between this and the version without line sets?
This bundle includes two pre-charged QuickConnect® line sets in your chosen length combination. The base bundle does not include line sets — you’d need to purchase them separately. If you already know your installation distances, this bundle is the more convenient option.

How do I choose the right line set lengths?
Measure the distance from your outdoor condenser to each indoor air handler location. Add a few feet of slack. Choose the combination that covers both runs — line sets cannot be shortened, so it’s better to go slightly longer than needed.

Can each zone be set to a different temperature?
Yes — each air handler operates independently. One zone can be cooling while the other is heating, or each can be set to different temperatures simultaneously.

How does the extended warranty work?
Register your unit after installation and enroll in the MRCOOL Care Program annually. Registered original owners qualify for 7-year full unit replacement for compressor failure and lifetime compressor replacement. Without registration, the warranty defaults to the standard 5-year parts / 7-year compressor coverage.

Does this qualify for tax credits or rebates?
Yes — as an Energy Star certified system with a 23.9 SEER2 and 10.0 HSPF2-4, this unit may qualify for the federal Residential Clean Energy Credit or utility rebate programs. Check with your local utility provider and a tax professional for eligibility.

Can I add more zones later?
No — the 18K condenser supports up to 3 zones maximum. If you need 4 or more zones, you’ll need a larger multi-zone condenser.

What is the warranty?
Standard coverage:

• 7-Year Compressor Warranty
• 5-Year Parts Warranty

Extended coverage (with registration + annual Care Program enrollment):

• Lifetime Compressor Replacement