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Home 18,000 BTU DIY 5th Gen Series
DIY 5th Gen Series

MRCOOL 18,000 BTU 5th Gen DIY Multi-Zone Wall Mounted Air Handler | R-454B - DIY-18-HP-WMAH-230D25-O

SKU DIY-18-HP-WMAH-230D25-O Wall Mount208-230V
$931.00
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High efficiency. Quiet performance. Easy installation.

A smart, reliable choice for year-round comfort.

Best for 9K-18K room setups:
  • Large bedrooms
  • Living rooms
  • Garages
  • Additions
18,000 BTU
Cooling
18,000 BTU
Heating
See specs
Quiet Inside
See specs
High Efficiency

Brand Information

MrCool
Support Number
(270)366-0457
Product Overview Full product description Read the longer product copy, features, and application notes.
MRCOOL — Wall Mount

MRCOOL 18,000 BTU 5th Gen DIY Multi-Zone Wall Mounted Air Handler | R-454B - DIY-18-HP-WMAH-230D25-O

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MRCOOL 18,000 BTU 5th Gen DIY Multi-Zone Wall Mounted Air Handler | R-454B - DIY-18-HP-WMAH-230D25-O

Summary

The 5th Generation MRCOOL® DIY® 18K BTU Ductless Mini-Split Heat Pump is a powerful solution for heating and cooling spaces up to 800 sq. ft. Designed for true DIY installation, this system eliminates the need for professional help, featuring a pre-charged 25-foot DIY® QuickConnect® line set (sold separately) with R-454B refrigerant that removes vacuuming requirements. With wireless remote, SmartHVAC app, and voice control via Alexa/Google Assistant, this system offers year-round comfort with innovative features like Follow Me function and Dry Mode.

Important

Designed for easy DIY installation without professional help.Registration recommended to activate extended limited warranty.Requires compatible condenser and line set (sold separately) for proper operation.

What's Included

  • 18,000 BTU Wall Mounted Air Handler (Model DIY-18-HP-WMAH-230D25-O)
  • Wireless Remote Control
  • DIYPRO® Cable
  • Installation Manual
  • User's Manual
  • Manufacturer Warranty Information

Features

  • True DIY installation - no specialized tools or HVAC technician required
  • WiFi control via SmartHVAC app (iOS/Android), Google Home, or Alexa
  • Follow Me® function tracks remote location for optimal comfort
  • Dry Mode for humidity control
  • Gold Fin® Condenser for superior corrosion resistance
  • Pre-charged QuickConnect® line set compatible (sold separately)
  • Quiet operation mode available
  • Energy Star Certified for energy efficiency
  • AHRI Certified for performance standards

Technical Specifications

SKU DIY-18-HP-WMAH-230D25-O
UPC 840255587044
Weight 35.49 lbs
Cooling BTU 18,000 BTU
Heating BTU 18,000 BTU
Maximum Coverage 800 sq. ft.
Refrigerant R-454B
Electrical 208/230V 1 Phase 60 Hz
Dimensions (HxWxD) 13.19" x 42.52" x 8.9"

Performance Data

SEER Rating High Efficiency
Heating Type Heat Pump
Noise Level 19-54.5 dB

Warranty

  • Extended Limited warranty with registration
  • 7 year compressor warranty
  • 5 year parts warranty

Manuals & Downloads

Safety Information

PROPOSITION 65 WARNING

Smart Control & Convenience

The MRCOOL DIY® 18K system offers multiple control options including the included wireless remote with LCD display, SmartHVAC app for iOS and Android devices, and voice commands through Amazon Alexa and Google Assistant. The innovative Follow Me® function enhances comfort by adjusting airflow based on the remote's location, ensuring even temperature distribution throughout your 800 sq. ft. space.

DIY Installation Advantages

This 5th Generation MRCOOL DIY® system features simplified installation with the DIYPRO® cable that eliminates the need for electrical conduit. The compatible pre-charged QuickConnect® line set (sold separately) with R-454B refrigerant removes the vacuuming requirement, making professional installation unnecessary. The Gold Fin® condenser provides exceptional corrosion resistance, ideal for coastal environments and ensuring long-term durability.

Specs & Documents Product details Open technical specs, manuals, videos, and product documents.

Technical Data

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Product FAQs

Product FAQs

Helpful answers matched to this product, brand, specs, and configuration.
Where should I purchase MRCOOL equipment?

MRCOOL products are sold through authorized retailers and distributors rather than directly by MRCOOL to consumers. Purchasing through an authorized seller helps confirm that the equipment is genuine and that the correct purchase records are available for product and warranty support.

Can MRCOOL components from different series, generations, or refrigerant platforms be mixed?

Do not assume that MRCOOL indoor units, outdoor units, line sets, controls, or accessories are interchangeable. Use only manufacturer-approved combinations for the exact model family; in particular, MRCOOL states that R-410A products are not compatible with R-454B products and the refrigerants must never be mixed.

What makes an eligible MRCOOL DIY system different from a conventional mini-split?

Eligible MRCOOL DIY systems are designed around installation-friendly components such as factory-precharged line sets and compatible connection hardware. The included components vary by generation and package, and electrical work, permits, clearances, and local code requirements still need to be followed.

Does MRCOOL send technicians to a home or jobsite?

MRCOOL does not dispatch field technicians. Its in-house team provides phone and email assistance for diagnosis, troubleshooting, and product guidance, while the owner arranges and pays for any local on-site technician unless a specific written warranty program states otherwise.

Why do I need the exact MRCOOL model and serial number?

The model and serial number identify the exact equipment, generation, capacity, and applicable documentation or warranty. Use the identification labels on the equipment and MRCOOL’s registration guidance rather than relying only on a product title or general series name.

Are all MRCOOL systems designed for do-it-yourself installation?

No. Only product families specifically identified by MRCOOL as DIY-capable should be treated as do-it-yourself systems. Other lines, including the Advantage Series, require professional HVAC installation, so always follow the installation requirements for the exact model.

Where can I find MRCOOL manuals, specifications, certifications, and installation documents?

MRCOOL maintains a documentation library and a product support center with model-specific installation manuals, owner manuals, technical documents, certifications, warranty information, and troubleshooting resources. Search using the exact model number because documents can differ by series, generation, capacity, and refrigerant.

What types of products does MRCOOL offer?

MRCOOL offers a broad range of comfort products, including ductless mini-splits, central ducted split systems, packaged heat pumps, geothermal systems, water heaters, fans, thermostats, line sets, and HVAC accessories. Available capacities, refrigerants, efficiencies, and features depend on the exact product family and model.

When should an MRCOOL system be registered?

Register the system as soon as possible after purchase and installation. Several MRCOOL residential warranty programs require registration within 60 days of installation, or within 60 days of purchase when the installation date cannot be verified, but the exact requirement is controlled by the warranty document for the specific product.

Where can I purchase replacement parts for an MRCOOL system?

MRCOOL recommends starting with the original place of purchase because many dealers can special-order replacement parts. If that is not available, use an authorized MRCOOL parts distributor and confirm compatibility with the exact model and serial number before ordering.

How can I contact MRCOOL customer or technical support?

MRCOOL provides support by phone at (270) 366-0457, by email at support@mrcool.com, and through its online support-request form. Have the exact model and serial number available so the support team can identify the correct product documentation and next steps.

Can MRCOOL support work with my local HVAC technician?

Yes. If a local technician is scheduled, MRCOOL’s in-house support team can help coordinate troubleshooting and product guidance with that technician. The technician should have the model, serial number, system configuration, measurements, error codes, and a clear description of the issue available.

Where can I find MRCOOL troubleshooting and error-code information?

MRCOOL’s support center provides separate technical-support sections for ductless systems, residential ducted systems, product-specific error codes, wiring guidance, installation procedures, and troubleshooting articles. Use the exact series and model because codes and procedures are not universal across all MRCOOL equipment.

How do I register an MRCOOL product for warranty coverage?

Register the product through MRCOOL’s online warranty-registration page. Be prepared to provide the serial number along with purchase, owner, installation-location, and installer information requested by the registration form.

Does every MRCOOL product have the same warranty?

No. MRCOOL publishes separate warranty terms for different product families, generations, and applications. For example, the current DIY 5th Generation warranty lists 5-year parts and 7-year compressor coverage, but that coverage should not be assumed for another MRCOOL series; always check the exact product warranty document.

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