MRCOOL DIY 18,000 BTU 20 SEER Ductless Mini Split AC and Heat Pump with Wireless-Enabled Smart Controller



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Coming in as one of the first brands to offer a multi zone DIY mini split, MRCOOL offers the DIY-18-HP-230B25 wall mounted air handler for use in almost any installation need while providing a simple installation process. When paired with the proper installation materials, installation is fast, convenient, and cost-effective with MRCOOL’s DIY-18-HP-230B25.


  • 18,000 BTU multi zone DIY wall mounted air handler
  • Generally suitable to cover an average room in ideal climates
  • Direct-from-manufacturer customer technical support available for all MRCOOL DIY units
  • 100% sealed and pre-charged system when installed with the right accessories
  • Energy Star certified
18,000 BTU

With a rated output of 18,000 BTU, the MRCOOL DIY-18-HP-230B25 wall mounted air handler can generally heat and cool an average room in ideal climates.
Please note that in order to function, this air handler must be installed with a compatible condenser, controllers, and other installation equipment, available at an additional cost. If you have any questions, please do not hesitate to contact us for details.


MRCOOL offers a 5 year parts and 7 year compressor warranty on their multi zone DIY units when installed following the installation instructions and registered online through the manufacturer.

Intelligent Comfort Whenever You Need It

With MRCOOL's WiFi compatibility built-in to each DIY air handler, you can control your home's comfort from anywhere in the world that you have Internet—across town or across the world. This WiFi is easily set up, further improving the ease of this unit's installation.

A DIY Installation Built to Last

When paired with MRCOOL's easy-install precharged line sets and air handlers, the DIY-18-HP-230B25 is installation ready for almost any wall-mounted application. With no need to evacuate the line sets or add refrigerant, this unit can support multi-room heating and cooling without the expensive labor cost of a regular mini split. With this major obstacle out of the way, you will only need to follow the instructions for the unit and hard wire the condenser to power.

Product Specifications

More Information
MRCOOL DIY 18,000 BTU 20 SEER Ductless Mini Split AC and Heat Pump with Wireless-Enabled Smart Controller
Weight (in lbs) 176.370000
Manufacturer MRCOOL
Additional Information install this innovative ductless system easily
Additional Information The system constantly monitors interior air temperature
Additional Information Precharged 410 Quick Connect Line sets.
Additional Information Sleep Mode easy to program to save money
Additional Information Horizontal louver will automatically keep the last position
Cooling BTU 18,000 BTU
Heating BTU 18,000 BTU
Decibel Level (dBA) Indoor Unit: 31-45
Energy Star Yes
Refrigerant R410A
SEER 18-20
EER 12.5
Liquid Line 1/4"
Suction Line 1/2"
Electrical 208/230V 1 Phase 60 Hz
Max Breaker Size 20 amps
Min. Breaker Size 15 amps
Mini-Split Type Wall Mounted
Zone Compatibility Single Zone
Height Indoor Unit: 13.19" | Outdoor Unit: 27.64"
Width Indoor Unit: 42.52" | Outdoor Unit: 33.27"
Depth Indoor Unit: 8.90" | Outdoor Unit: 14.29"
Additional Info Indoor Unit Weight: 30.20 lbs | Outdoor Unit Weight: 98.77 lbs
Warranty 7 Years Compressor and 5 Years Parts Limited Warranty with Online Registration
Resources You will need Adobe® Acrobat® Reader to view PDF documents.
Safety Information PROPOSITION 65 WARNING

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Questions and Answers

Customer Questions
What is the length of the line kit from indoor to outdoor unit?
The line set kit included with this DIY system is 25 feet long. If you have any further questions, please call us and we will be happy to assist you.
What is minimum temperature it will still heat
The manufacturer states it will heat down to 5 degrees Farenheit.
will it heat a 700 square foot room
Yes, this unit can heat a space that size. For more information, please visit our sizing guide
what generation is this current model
Thank you for your question. This unit is a 3rd generation model. 
What is the HSPF rating or the DIY 18,000 BTU 20 SEER unit?
This unit has an HSPF rating of 10. If you have any further questions please feel free to give us a call! Thanks.
What is the difference between the advantage and the diy models?
The advantage series are traditional mini splits, while the DIY mini splits come with a 25 foot pre-charged line set. The DIY mini split allows you to do the HVAC portion of installation yourself because there is no adding or removing of refrigerant. If you have any further questions please feel free to give us a call! Thanks.
Where are they manufactured?
MRCOOL is based out of Kentucky however most of their mini-splits are manufactured in China.
Is there a way to get a longer or extension for the line set?
Thank you for your question. This particular MRCOOL system only comes with the 25 ft line set. One solution, if possible, would be moving the location of the outdoor unit closer to the position of the indoor unit. For more assistance, please give us a call.
Can I change my central air and heat with this product?
This system can be used as an alternative to central heating and air. This is a ductless system, so no ductwork is required. This MRCOOL system is a single zone system which as a general rule of thumb heats and cools one room or open space. If more zones are needed, multi zone systems are available. For more assistance, please give us a call.
Does this unit come ready to install?
Thank you for your question. Other than the tools needed for installation, a condensate drain line will be required. This drain line will drain condensation away from the indoor air handler. Usually this drain line runs down from the unit and gravity carries it away from the unit. But if your installation requires the drain line to go against gravity, a mini condensate pump removal will be required. We would also recommend a wall bracket, equipment pad or condenser slab stand to set your condenser on. Another recommended product is the line set cover guards. These not only protect your line sets, they provide a cleaner look. These items can be found under the accessories section for this product, which is located under the add to cart button on the right hand side of the screen. For more assistance, please give us a call.
Can the refrigerant tubing exit the side of the inside unit and be run down and interior wall?
Yes, there should be a knockout on the side with enough room for the refrigerant tubes, control wire and drain hose to exit. Then the line set can be angled down at a "soft 90 degrees", being careful not to kink the tubes as you make the bends. If you have any further questions please feel free to give us a call! Thanks.
Can the indoor unit go closer to the floor or does it have to be up high?
Thank you for your question. When selecting an installation location for the indoor unit there are several guidelines to consider. According to the installation manual, in homes with a ceiling higher than 9', the indoor unit should be 90.55 inches above the floor. In homes with ceilings lower than 9', the indoor unit should be 78.55 inches above the floor. In addition, the indoor unit should be at least 5.9 inches below the ceiling and should have a clearance of at least 4.75 inches on both sides. The installation location of the indoor unit should also have good air circulation, convenient drainage for the condensate drain line, where minimal noises from the unit will not be a disturbance, at least 3' away from all other electrical devices and a solid location that can support the weight of the unit and will not vibrate. For more information regarding selecting the installation location of the unit, please reference pages 15 and 16 of the installation manual. This manual can be found...
What is the sound db of the outside unit?
Thank you for your question. This system has a rated noise level of 45 dB(A). For more assistance, please give us a call.
What is the amperage of this unit?
Thank you for your question. This system has a power supply of 208-230 V. 60 Hz. 1 Ph. It requires a minimum circuit of 15 Amps and a maximum fuse of 20 Amps.
When the room reaches the desired temperature does the fan turn off?
Thank you for your question. The fan for this system will run continuously as long as the system is turned on. It runs in an effort to maintain the room's air comfort. However, the fan requires a very minimum amount of power and the fan speed can be adjusted. For more assistance, please give us a call.
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