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MrCool DIY 4th Generation Heat Pump Wall Mount Air Handler

✔️Use Code: MRCOOL3 For 3% Off Your Order

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✔️Free Shipping & No Sales Tax

✔️Authorized Dealer

✔️Questions? Call 650-719-8896 or Chat Us Below

Customer Reviews

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Introducing the MRCOOL® DIY® 4th Generation, the ultimate DIY heating and cooling solution. With its easy installation and advanced features, you can create your own comfort zone without the need for professional assistance. The DIY® 4th Generation features smart connectivity, allowing you to control your system from anywhere using your smartphone. It offers efficient and reliable performance, adjustable airflow, and precise temperature control. Designed with innovation and convenience in mind, the MRCOOL® DIY® 4th Generation puts you in control of your indoor climate. Experience comfort on your terms with this cutting-edge DIY system.


  • Easy DIY® Installation

    • Precharged R-410 Quick Connect® Line Set
      • Pre-charged linesets allow you to install this innovative ductless system without special tools, equipment, or training.
      • Couplers are available for extended lengths.
  • Energy Star
    • Certified Efficiency
    • Going above and beyond for efficiency while maintaining optimum performance and reliability, the 12K, 18K, and 24K models are Energy Star Certified.
  • Smartphone App
    • Enhanced Control from Anywhere
    • Control your MRCOOL DIY® anywhere with your Apple or Android smart device and an internet connection.
  • NEW DIYPRO™ Cable
    • Safety & Durability
      • The included DIYPro™ Cable eliminates the need for electrical conduit.
      • Provides higher mechanical protection and durability.
  • Follow Me® Function
    • Personalized Performance
      • Keep the remote close by.
      • MRCOOL DIY® will track the air temperature around you.
      • Ensures you receive maximum comfort.
  • Leakage Detection
    • Protecting Your Investment
      • When the MRCOOL DIY® detects low coolant:
        • An alarm will sound to alert you to the problem.
        • This prevents damage to the compressor.
        • Allows you to maintain high air comfort.
  • Low Ambient Cooling
    • Cooling Down to 5°F
      • This feature allows the MRCOOL DIY® to cool down to 5°F.
      • Makes it the ideal system for:
        • Server rooms
        • Greenhouses
        • Any other application that requires cooling all year.
  • Auto Restart
    • Never Lift a Finger
      • In case of a power outage:
        • Don't worry.
        • The MRCOOL DIY® has an auto restart feature.
        • The unit will be up and running again in no time at all.
  • Sleep Mode
    • 24-Hour Comfort
      • Sleep Mode is designed to provide 24-hour comfort.
      • It is easy to program.
      • Helps save money on energy costs.
      • Allows you to sleep a little easier.
  • Louver Position Memory
    • Remembers So You Don't Have To
      • The horizontal louver of the MRCOOL DIY® has a position memory feature.
      • It automatically moves to the same position as you set the last time the unit was turned on.
      • You don't have to manually readjust the louver position every time you use the unit.
  • Gold Fin® Condenser
    • Corrosion Resistant
      • The condenser of the MRCOOL DIY® features Gold Fin® technology.
      • It is built to resist long-term corrosion.
      • Ideal for those living on the coast or in environments with high humidity or salt exposure.
      • Provides durability and extends the lifespan of the unit.
  • Digital Assistant Ready
    • Google Assistant & Amazon Alexa
      • The new MRCOOL® Smart HVAC Controller® Module and App are fully compatible with Google Assistant and Amazon Alexa.
      • Allows you to control your MRCOOL DIY® system using voice commands.
      • Enjoy the convenience of integrating your HVAC system with your preferred digital assistant.
      • No additional setup or configuration required; it supports Google Assistant and Amazon Alexa out of the box.



Installation Manual


Remote Manual




Limited Lifetime* & 7 Yr Replacement* on Compressor + 5 Yr Parts


4th Gen DIY®s have an optional LIMITED LIFETIME compressor warranty*, a 7-year compressor replacement* warranty, and a standard 5-year parts warranty for the original registered owner. 




Return Policy

You have 30 days to initiate a return process for items that are unused and in their original packaging.

If you receive an order that is damaged, defective, or incomplete, please don't hesitate to get in touch with us using the following contact information:



Items must be returned within 30 days of delivery to be eligible for a refund. Please note that returns received without a return authorization number will not be refunded.

Why Choose MrCool

  1. Innovative Technology: MRCOOL is at the forefront of HVAC technology, consistently introducing innovative features and solutions to enhance comfort and efficiency.

  2. Energy Efficiency: MRCOOL products are designed with energy efficiency in mind, helping you reduce your energy consumption and lower your utility bills.

  3. Reliability and Durability: MRCOOL is committed to producing high-quality, durable products that withstand the test of time, ensuring long-lasting performance and reliability.

  4. Customer-Centric Approach: MRCOOL prioritizes customer satisfaction, actively engaging with customers, understanding their needs, and delivering tailored solutions.

  5. Ease of Installation and Use: MRCOOL products are designed for hassle-free installation and user-friendly operation, making them accessible to both professionals and homeowners.

  6. Diverse Product Range: Whether you need air conditioners, heat pumps, gas furnaces, or ductless mini-split systems, MRCOOL offers a wide range of HVAC solutions to meet your specific requirements.

  7. Industry-Leading Support: MRCOOL provides exceptional customer support, offering technical assistance, warranty coverage, and responsive service to ensure a positive experience.

  8. Environmental Responsibility: MRCOOL is committed to sustainability, developing environmentally friendly HVAC solutions that reduce carbon footprint and promote a greener future.