What's in the box
- MRCOOL® 9K DIY® 5th Gen Mini-Split Air Handler
- 25ft DIYPro™ Communication Cable
- Wireless Remote Control
- Installation Accessories
- MRCOOL® Warranty
Free curbside shipping on eligible MRCOOL® systems across the continental U.S. Most products ship in 3–5 business days and arrive in 4–10 days, depending on your location. Freight carriers will call to schedule delivery.
Returns accepted within 30 days on new, unopened items in original packaging. A restocking fee of up to 35% may apply for HVAC equipment — we’ll always confirm before issuing a return authorization.
Each MRCOOL® system is backed by manufacturer warranty coverage as defined by product and model — typically 5–10 years on major components. Register your system after installation to activate full coverage.
Need help with sizing, voltage or compatibility? Email support@coolheatdirect.com — our U.S. team replies within one business day.
Manuals & documents
MODEL: DIY-09-HP-WMAH-115D25-O
Powerful, Ultra-Quiet Comfort for Spaces up to 400 sq. ft.
The MRCOOL® 9k BTU DIY® 5th Generation Mini-Split Air Handler delivers efficient, whisper-quiet heating and cooling designed for hassle-free, do-it-yourself installation. Perfect for bedrooms, home offices, nurseries, and compact living spaces up to 400 sq. ft., this unit pairs effortlessly with your MRCOOL® DIY® 5th Gen Single-Zone or Multi-Zone Condenser.
With its pre-charged 25-foot Quick Connect® line set filled with eco-friendly R-454B refrigerant, installation is fast, clean, and requires no vacuum pumps or HVAC professionals. The included DIYPro™ Communication Cable replaces the need for traditional electrical conduit and is designed to withstand outdoor elements.
Take complete control of your home’s climate with the SmartHVAC® app, Amazon Alexa, or Google Assistant voice commands. The built-in Follow Me® function ensures the system maintains your ideal room temperature by sensing the location of the wireless remote.
Protected by Gold Fin® corrosion-resistant coating, this air handler is built for lasting performance, even in coastal or high-humidity environments. Enjoy reliable, efficient year-round comfort backed by one of the best warranties in the industry.
Why You’ll Love It
✅ Perfect for Small to Medium Spaces — Ideal for bedrooms, home offices, and dens up to 400 sq. ft.
✅ True DIY Installation — Quick Connect® pre-charged line sets and DIYPro™ cable make setup simple — no HVAC pro needed.
✅ Smart-Home Ready — Wi-Fi enabled, works with SmartHVAC® app, Alexa, and Google Assistant.
✅ Follow Me® Personal Comfort — Wireless remote measures temperature where you are, adjusting for personalized climate control.
✅ Ultra-Quiet Operation — Whisper-quiet performance as low as 18 dBA for peaceful spaces.
✅ Gold Fin® Condenser Protection — Corrosion-resistant coating ensures durability in coastal or humid climates.
✅ All-Season Heating & Cooling — Operates from 5°F to 86°F, keeping your space comfortable year-round.
✅ Industry-Leading Warranty — Limited Lifetime Compressor Warranty (with registration), 7-Year Compressor Warranty, 5-Year Parts Warranty.
What’s Included:
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MRCOOL® 9K DIY® 5th Gen Mini-Split Air Handler
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25ft DIYPro™ Communication Cable
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Wireless Remote Control
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Installation Accessories
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MRCOOL® Warranty
Questions, answered
Everything homeowners ask before buying a MRCOOL® system.
Installation
Do I need an HVAC technician to install this?
No. MRCOOL® DIY systems are designed for homeowner installation. The pre-charged Quick Connect® line set means there's no refrigerant handling, no vacuum pump, and no special tools or license required.
How long does installation take?
Most single-zone systems go in within a few hours: mount the indoor air handler, set the outdoor condenser, connect the pre-charged line set, and power it on.
Do I need an electrician?
The system needs a dedicated circuit. Most homeowners have a licensed electrician add the breaker and disconnect — everything else you can do yourself.
Sizing & compatibility
What BTU size do I need?
As a rule of thumb: up to 400 sq ft → 9–12K BTU, 400–600 sq ft → 12–18K, 600–1,000 sq ft → 18–24K. Use the room-size guide above and factor in insulation, ceiling height and sun exposure.
Will it heat in winter?
Yes — these are heat pumps, so they heat and cool. Many MRCOOL® systems keep heating in sub-freezing temperatures; check each model's spec sheet for its low-temperature heating range.
115V or 230V — which do I need?
9K–12K units are usually 115V (standard outlet circuit); 18K and larger are typically 230V. The voltage is shown in the product options and specifications.
Warranty & support
What warranty is included?
MRCOOL® systems carry manufacturer warranty coverage — typically 5–10 years on major components when you register your system after installation.
How do I get help choosing or installing?
Email support@coolheatdirect.com — our U.S. team replies within one business day with sizing, voltage and compatibility help.
Shipping & returns
How fast does it ship?
Most products ship in 3–5 business days with free curbside delivery in the continental U.S. The freight carrier calls to schedule your delivery.
Can I return it?
Returns are accepted within 30 days on new, unopened items in original packaging. A restocking fee may apply to HVAC equipment — we always confirm before issuing a return authorization.
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