What's in the box
- MRCOOL® 12K 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-12-HP-WMAH-230D25-O
Effortless, High-Performance Comfort for Spaces up to 550 sq. ft.
The MRCOOL® 12k BTU DIY® 5th Generation Mini-Split Air Handler delivers powerful, energy-efficient heating and cooling in a sleek, wall-mounted design — ideal for larger bedrooms, home offices, living areas, or converted garages up to 550 sq. ft.
Designed for fast, professional-grade installation without the professional tools, this unit connects easily to your MRCOOL® DIY® 5th Gen Multi-Zone Condenser using a pre-charged 25-foot Quick Connect® line set with eco-friendly R-454B refrigerant. No vacuum pump, no gauges, no hassle.
Seamlessly control your system with a wireless remote, the SmartHVAC® app, or voice commands via Amazon Alexa and Google Assistant. Follow Me® technology ensures your room stays at the perfect temperature based on your exact location.
Protected by a durable Gold Fin® corrosion-resistant coating and backed by industry-leading warranties, this air handler offers reliable, quiet performance you can trust — season after season.
Why You’ll Love It
✅ Perfect for Medium-to-Large Spaces — Ideal for master bedrooms, home offices, dens, and living areas up to 550 sq. ft.
✅ Simple DIY Installation — Pre-charged Quick Connect® lines and included 25ft DIYPro™ Communication Cable mean no vacuuming, gauges, or HVAC pro required.
✅ Smart-Home Compatible — Wi-Fi enabled for easy control via the SmartHVAC® app, Alexa, or Google Assistant.
✅ Follow Me® Comfort Technology — Automatically adjusts based on your exact location for precision, personal comfort.
✅ Ultra-Quiet Performance — Operates between 27 and 41 dBA for peaceful, low-noise operation.
✅ Gold Fin® Protection — Corrosion-resistant coating extends system durability.
✅ Year-Round Efficiency — Cools down to 5°F and heats up to 86°F, delivering dependable comfort in any season.
✅ Industry-Leading Warranty — Limited Lifetime Compressor Warranty (with registration), 7-Year Compressor, and 5-Year Parts Warranty.
What’s Included:
-
MRCOOL® 12K DIY® 5th Gen Mini-Split Air Handler
-
25ft DIYPro™ Communication Cable
-
Wireless Remote Control
-
Installation Accessories
-
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.
-
Genuine MRCOOL® Systems -
DIY-Friendly Installation -
U.S. Shipping -
Secure Checkout -
Sizing Help
