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MRCOOL® DIY 5th Gen · Multi-zone · 4 rooms 4-Room DIY Mini Split System, 48,000 BTU Outdoor Unit
Indoor units4 wall units: 6K + 12K + 12K + 18K
Price includes your line sets below
1. Pick a line set length for each room
Measure along the wall from where the indoor unit will go to where the outdoor unit will sit, then add 3 ft. Pick the next length up. Extra line set coils behind the outdoor unit. It can’t be cut.
66 and 75 ft: two line sets joined by a coupler kit, included in the price.
2. Add what you’ll need to install it Optional
Sold separately. Most installs add a cover, disconnect, whip and pad.
Sizing questions? Call +1 (844) 999-9725 Mon–Fri, 9–5 EST
You can install it yourselfNo vacuum pump needed
Each room, its own tempSet each room from the app
Heats down to −13°FHeats and cools all year
5 yr parts, 7 yr compressorPlus a lifetime option
Will it fit your home?
Each indoor unit is sized for one room. Check your rooms against these, length × width.
A room is bigger than its unit? Pick a system with a bigger unit for that room, or call us and we’ll find the right mix. Sizing guide
What this system covers in a home
Each wall unit covers its own room, up to the size shown. Other rooms only get the air that reaches them through open doors.
Example home with this system: one wall unit in each of 4 rooms, the biggest in the living room. Rough estimates. Every home is different: the layout, doors, ceiling height, insulation and fan speed all change how far the air reaches.
Want one more room covered? Pick a 5-room system with a unit there. 5-room systems →
Specs for this system
- Line
- MRCOOL DIY 5th Gen multi-zone
- Outdoor unit
- 48K, runs up to 6 rooms
- Indoor units
- 4 wall units: 6K + 12K + 12K + 18K
- Room size, up to
- 2,000 sq ft in total
- Cooling capacity
- 43,000 BTU/h
- Heating capacity
- 48,000 BTU/h
- Heats down to
- −13°F outside
- SEER2 / EER2 / HSPF2
- 21.8 / 12 / 10
- Power
- 230V, one circuit to the outdoor unit
- Circuit
- 40 A minimum, 45 A max fuse
- Refrigerant
- R-454B, pre-charged
- Line sets
- Quick Connect, the lengths you pick
- Outdoor noise
- 64 dB(A)
- Control
- Remote, MRCOOL app, Alexa, Google
- Warranty
- 5 yr parts, 7 yr compressor, lifetime option
- Outdoor unit model
- DIY-MULTI6-48HP230D-O
Line set limits from MRCOOL
Can you install a 4-room system yourself?
Yes. It’s the same job as a single room, done 4 times, plus one outdoor unit. Plan a weekend or two.
“Easy install. Took me 2 full days to install 4 wall units.”Michael, Trustpilot
- Mount each indoor unitScrew each wall plate into studs, level it and drill one hole per room.
- Run the lines throughFeed each line set, wire and drain hose outside, then hang the unit.
- Set the outdoor unitPut it on a level pad or wall bracket, close enough for every line set.
- Connect each line setOne port per room. Snug with two wrenches, then open the valves.
- Wire the powerWire one 230V circuit. An electrician can do just this part.
- Check for leaks and testCheck each fitting with soapy water or a leak detector, then run a test.
The part people ask us about
The electrical The outdoor unit needs one dedicated 230V circuit and a disconnect within sight of it. The indoor units are powered through their communication wires, so no outlets are needed inside. If you’ve never added a 230V circuit, have an electrician do just that part.
The line sets MRCOOL allows up to 75 ft to any one room, 221 ft for all rooms added together on the 48K, and 24 ft of height difference between two indoor units. The length picker above keeps you inside these. See the limits
The drain Each unit comes with a drain hose that drains by gravity, so it has to run downhill outside. Unit lower than the drain? Add a condensate pump made for mini splits, like the Sauermann Si-30 or Little Giant EC-400. We don’t sell pumps.
What’s in the box, and what isn’t
- 48K outdoor unit, factory charged with R-454B
- 4 wall units (6K, 12K, 12K, 18K), each with its mounting hardware and remote
- 4 pre-charged Quick Connect® line sets, the lengths you pick,
sized to each unit - Communication wire and drain hose for each room
- Install and owner’s manuals
Not in the box
Every multi-zone outdoor unit runs on 230V and needs these. Tick them in step 2 above.
- Disconnect switch, 60A, and an electrical whip
- Outdoor pad
- The 230V circuit and breaker from your panel
Your cart lists the outdoor unit, each indoor unit and each line set as separate lines, so you can see exactly what ships.
What’s built in
The features that make the DIY 5th Gen easy to install and easy to live with.
Quick Connect® line setsPre-charged lines that screw on by hand. No vacuum pump or gauges needed.
Refrigerant leak detectionEach indoor unit senses a refrigerant leak and shuts the system down safely.
Gold Fin® condenserA coating on the outdoor coil that resists rust and corrosion, so it lasts longer outside.
DC inverterThe compressor speeds up and slows down instead of cycling, so it uses less power.
Low ambient coolingKeeps the AC running in cold weather for hot rooms, like a server room or gym.
App, Alexa and GoogleControl each room from your phone or by voice. WiFi kit included.
Follow Me®The remote reads the temperature where you sit, so the room feels right where you are.
Auto restartAfter a power outage, it turns back on by itself with the same settings as before.
DIY Pro® cableOne cable powers each indoor unit, so you don’t need any outlets inside.
Warranty, even when you install it yourself
MRCOOL covers DIY installs on its DIY lines, and we’re an authorized dealer, so you get the full warranty.
MRCOOL sets the terms, so read the warranty. How to register it.
MR COOL DIY IS THE BEST.
“I’ve had for about a year now and the performance has been flawless. It was a diy installation and I didn’t have any problems.”
Mr. BakerBest price and fast shipping
“Good experience, best price and fast shipping. Had a question and they got back to me quickly. I bought the Mr. Cool 36000 btu 3 zone mini split.”
Barry BowenGreat people
“Easy to talk with, made sure I was getting the right system for my needs, great price, and followed through with communications till delivered.”
Pete SwegerAs easy as they claim
“It was actually as easy to install as they claim it is… couldn’t be happier with the performance so far.”
JimPiece of ‘Cake’
“The rep on the phone was helpful with confirming that… I’m amazed at how straightforward the process is. Should be fun, and I’ll save a lot of money.”
Byron GabrielsenDIY 2 zones, 18k
“Packaging and shipping was great. Response time to questions was good. The two zones are performing nicely, and super quiet!”
K. WestfallDelivery handled
“Your help coordinating and managing the delivery was excellent. You have a great team.”
Andy ArenthVery helpful sales
“Cool-minisplits website beat everyone on price… I called and found out that they are very reliable… Items shipped out quickly and arrived in good condition.”
Robert JohnsonGreat customer support
“The order came quickly. One part was damaged by the carrier so I called and they immediately shipped a new part.”
Zac HGreat and honest business
“The 24k Mr Cool was a perfect solution for my garage… Easy install and the staff are always there to answer any questions.”
Todd BaileyEasy install
“Easy install. Took me 2 full days to install 4 wall units.”
MichaelMr. Cool as a DIY project
“I was very interested in the DIY portion of the product. It was involved, but I’m fairly handy and found it very doable and everything works fine.”
WaltGreat service
“Purchase went without a problem and all my questions were answered without delay. I was notified when the unit shipped.”
Scott IverslieAttention to detail
“I threw him so many curveballs and order changes and he still got it all correct… Appreciate all the personal attention to detail and following up.”
Tim HedrickTop notch
“Their customer service is too notch! The product is amazing!!!! … I recommend this to any Contractor any homeowner anyone who’s looking for a mini split system!”
Dean R Sun
Shipping and returns, in plain words
When it arrives
Business days, counted once your order is confirmed. Transit time is an estimate set by the freight company, not a guarantee. Free shipping on kept orders in the 48 contiguous states. Hawaii and Alaska ship by quote.
How it’s delivered
Freight truck with a liftgate, set down at the curb. It can’t deliver inside gated communities or other limited access locations. It may come in several boxes, so have someone help carry them in.
Box damaged? Refuse only the damaged item and keep the rest. We ship a replacement right away.
If you change your mind
Before it ships Full refund, minus the 3% non-refundable card fee.
After it ships Within 30 days, unused and in the box. We deduct the 3% card fee, shipping both ways and MRCOOL’s 10% restocking fee.
Damaged or wrong item? We cover everything. Return policy
Multi-zone questions
Can the rooms add up to more than the outdoor unit?
Only by 6K at most, and only in mixes MRCOOL approves. This system is 6K + 12K + 12K + 18K = 48K on a 48K outdoor unit. That’s within the outdoor unit, so every room can run at full power at once.
Can I pick a different length for each room?
Yes. Each room gets its own line set, sized to its unit. Pick the shortest length that reaches.
My run is longer than 50 ft. What then?
Pick 66 or 75 ft. You get two line sets and a coupler kit to join them. 75 ft is the most MRCOOL allows for one room.
Can I add a room later?
This system uses 4 ports on the outdoor unit. If you might add a room, call us before you order and we’ll check which outdoor unit leaves a port free.
Do I need an HVAC technician?
Not for the refrigerant side: the line sets are pre-charged and connect with two wrenches. You may want an electrician for the 230V circuit.
Do you help with the install?
We don’t do installs or install support. Call before you buy and we’ll help you pick the right system. After that, the manuals and MRCOOL support are the place to go.
Full product description
One outdoor unit, four rooms, each with its own temperature.
This MRCOOL DIY 5th Gen system runs 4 wall units (6K + 12K + 12K + 18K) from one 48K outdoor unit. Each unit is sized for its own room (6K up to about 250 sq ft, 12K up to about 550 sq ft, 18K up to about 800 sq ft), and the whole system covers up to about 2,000 sq ft in total. It heats and cools, and keeps heating down to −13°F.
Features
- Quick Connect® line sets: pre-charged and screw on by hand, so you don’t need a vacuum pump or gauges.
- Refrigerant leak detection: a sensor in each indoor unit watches for refrigerant and shuts the system down safely if it finds a leak.
- Gold Fin® condenser: a coating on the outdoor coil that resists rust and corrosion.
- DC inverter: the compressor speeds up and slows down instead of switching on and off, so it uses less power and keeps the temperature steady.
- Low ambient cooling: keeps cooling even when it’s cold outside.
- SmartHVAC app, Alexa and Google: control each room from your phone or by voice. A WiFi smart kit comes with each indoor unit.
- Follow Me®: the remote reads the temperature where you sit, so the room is comfortable where you are.
- Auto restart: after a power outage, it turns back on with the same settings.
- DIY Pro® cable: one cable carries power and communication to each indoor unit, so you don’t need outlets inside.
Built for a DIY install
Hang the indoor units, set the outdoor unit, connect each line set and wire the power. If you’ve never added a 230V circuit, an electrician can do just that part.
Pick a line set length for each room
Choose 16, 25, 35 or 50 ft for each room in the menu above. For longer runs, 66 and 75 ft are two line sets joined with a coupler kit, included in the price. MRCOOL allows up to 75 ft to any one room and 221 ft in total on the 48K.
What’s in the box
- 1 × 48K outdoor unit, factory charged with R-454B
- 4 × wall units (6K + 12K + 12K + 18K), each with its mounting hardware, remote and WiFi smart kit
- 4 × pre-charged Quick Connect® line sets, in the lengths you pick
- Communication wire and drain hose for each room
- Install and owner’s manuals
Not included: disconnect switch, electrical whip, outdoor pad or wall bracket, and the 230V circuit from your panel.
Specs at a glance
- Outdoor unit: 48K, 230V, R-454B
- Indoor units: 4 × wall units (6K + 12K + 12K + 18K)
- Covers: about 2,000 sq ft in total
- Heats down to: −13°F
- Warranty: 5 years parts, 7 years compressor, with a limited lifetime warranty option from MRCOOL
Delivery
Ships free to the 48 contiguous states by freight truck with a liftgate, set down at the curb. Freight trucks can’t deliver inside gated communities or other limited access locations. See our Shipping Policy.
Ready to order?
4-room DIY 5th Gen system, 48K outdoor unit, free shipping to the 48 states.
