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Looking for “How to Install a Minisplit”

kyeser | Posted in General Questions on

I have viewed most of the youtube videos, and looked for a publication, but I have failed to find a step by step, how to how to install a mini split heat pump. We had our Fujitsu installed about a month ago at our own home and I helped the HVAC do the install, I’m just not 100% on doing it myself yet.

I really think most builders with some speciality tools and some direction should be able to install a minisplits.

Any resources would be greatly appreciated…

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  1. jinmtvt | | #1

    Hi Kye,
    you ca start by reading this thread

    there might be other related thread if you use the search engine.

    Installing pre-charged mini-splits is not a very complex task, but it does require some pro tooling and a few hours of study ( manuals, youtube videos, pictures etc.. )

  2. kyeser | | #2

    Thanks Jin. I reviewed the thread and there were some great tips.

    However would it possible for you to give me a quick step by step as to how to hook up a condenser as you seem to be quite fluent in these matters. I am just looking for the proper sequences.. when to hook up what to where... when to open up each valve... I know this seems basic to someone who has installed these units but it would get me started in the right direction.

    Happy Holidays

  3. jinmtvt | | #3

    Kye i am far from expert on the subject, but i did succeed multiple installations.

    I can only provide with a general list, you will need to revise your manufacturer's installation manual, and try to view as many youtube videos as possible to associate ideas with images.

    - Determine proper location of interior and exterior unit and verify that order pre-cut cable is long enough for the job

    - Mount interior head ( drill hole for hoses, determine angles etc.. )

    - Mount Exterior unit on wall/rack/stand as decided.

    - Connect line-set to interior unit using pro torque wrench and correct values ( per manuf instruct )

    - Connect line-set to exterior unit and torque same

    - Use a pro vacuum pump with a gauge ( get a good digital one that goes down to 100microns or less ) and connect to the free port on the 3way walve on the exterior unit to draw vacuum in the line sets ( stop when the reading stop moving or you have attained lower than 100microns rating , which also means that you should not have any leaks, but not 100% )

    - Remove Vacuum tooling, and open up Exterior unit 3way valve ( you will release the pre-charged in the line sets and around , usually 2 valves to open up , slowly )

    - Proper electrical connections to exterior unit, power on everything, verify that both cooling and heating works ( takes a few minutes when switching from 1 to the other , patience )

    - Test for leaks at connections with very soapy water ( if no bubbles, grow from frale connections, you should be good to go ! ) and hide/seal everything

    Not many possible errors on newer pre-charged models, but any error would cost you a visit from a tech.

    Never forget that all except 1 brand if i recall correctly, void your warranty if not installed by a qualified and certified trade guy.
    Worth it when you are installing many units, not worth the saves if you are installing only 1-2.
    ( you still need to buy 5-700$ of tooling for a proper job )

    happy Xmas

  4. srenia | | #4

    Remember when you install your mini split yourself you void all warranties. Also getting an installer later to work on it is very difficult. Also city might come down on you as well since you are not licensed for the install. Even the EPA could come after you as well.

    Mini Split's are not to be installed by non professionals. Period!

  5. jinmtvt | | #5

    S E: what about a house, fixing your car, assembling an audio amplifier ??

  6. kyeser | | #6

    Thanks a bunch Jin!

    S E: FYI there are no such thing as licensed Electricians or Plumbers or Contractors where I live in Northern New York. Even if I wanted to hire a guy with a "license" no such license exists. Every state is different.

  7. Cyrus Collins | | #7

    Depending on where you are located there may also be rebates available that doing a DIY install might void. In the Northwest there are a couple of companies like this: which let you do any level of the install and provide support as well as warranties and rebates.

  8. charlie_sullivan | | #8

    The cost of a mistake is not just needing a visit from a tech--it's also release of refrigerant with high global warming potential. Your net impact on climate could be worse than if you'd just used electric baseboard heat.

  9. wjrobinson | | #9

    More and more every year pro work is getting a DIYer make over.

    Daikin has interesting information at their site to do with refrigerants and what to do about global warming. Note DIY installation is not the cause of global warming.

  10. gusfhb | | #10

    Step one: Open the box
    Step two: read the enclosed instructions
    Step three: follow the aforementioned instructions

    I personally use a professional to do the freon, since they have the tools etc. and encourage you to find a friend of a friend of a friend in the business to do so.

    As far as the warranty goes, so what? for what the HVAC guys charge to sell and install one you can buy two online

  11. kyeser | | #11

    Charlie Why is electric baseboard so bad. In my area of the country electricity is produced 99% hydro. Very low GWP. My municipality gives us a breakdown annually of where our power comes from. 3.5 cents per KWH. Thanks Hydro Quebec.

    As far as installation of the mini splits, hardest part being flaring the linesets,.... if you can flare a set of brake lines on a car what is the difference.

    I think people generally have a fear of the unknown. With a little bit of guidance I think anybody with the right set of tools and mechanical ability can easily install a minisplit.

    How professional are the professionals in your area?

    I can tell you there is a lot of knuckheads out there who work for HVAC companies who are just as likely to make a mistake with the flare connections as the diligent carpenter with some mechanical skills.

    This is why I am trying to get some guidance and do it myself!

  12. jinmtvt | | #12

    You don't get to flare lines anymore, you buy already flared line-sets with at a pre-cut length required for your installation and be done with it.
    Eliminates probably 90% risks of flaring job.
    Then the gaz comes pre-charged in most machines, you don't have to deal with it unless you've got a leak in your installation.

    The warranty is good on those products, up to 10 years on the compressor, so you need to weight the pros-cons carefully VS your savings+ labor time + tools.

    As i said, unsure it is worth the hassle for a single unit installation, but if you've got 2+ and plan on installing at your friend's/family's places afterward...why not get equipped properly and save everybody some cash.

    ROI is very dependent on the "I".

  13. srenia | | #13

    Get lines that are pre flared... lines need to be exact size. Copper lines will cinch easily when bending. Extra length needs to go somewhere.
    Flaring your own lines... flare is different on HVAC lines
    Lines need to be vacuumed... at least 300 dollar tool on sale for a descent pump/guages and upwards.
    Leak in the mini split... quality control isn't perfect on these units. If you install it yourself you have a worthless unit. No warrantee if not bought through a professional installer.
    Make a mistake and you have to call in a professional to find the leak and refill the unit. Good luck finding a professional that will fix the mess you created.
    Bottom line is mini splits have to be installed by professionals. If you want to have a heat pump that you install yourself the only option is pthp units.
    Mini split installs isn't fixing your car or other projects you can read instructions about. Experience, proper tools and warranties are needed for these installs. Even then they can be temperamental. If you don't have enough money for a professional to install them you should not buy a mini split! This tech is great. More of this tech will be in future PTHP's so patience is needed for the do it yourself crowd. .

  14. patrickoneal | | #14

    There's really not much to installing them, other than the cost for proper tools. It's not rocket surgery. If you do 100% of the install yourself, you'll need:

    A good vacuum pump capable of pulling down to 500 microns.

    A good micron gauge, like a bluvac, it can be exposed to pressure and refrigerant, which will make the job easier.

    A good flaring tool, don't trust factory flares, make your own. Also, put some Nylog sealant/lubricant on the front and back of the flares prior to connecting

    A decent torque wrench with crow's foot sockets.

    A valve core removal tool with shutoff valves is good too, like the Appion Megaflow core removal tool. You can attach the bluvac to the side, pull the valve core, attach the vacuum pump to the end, and pull a vacuum. Then you can close the valve and make sure you're not leaking vacuum by observing the BluVac gauge. You really do need the valve there, because your manifold or hose will likely leak too much vacuum after you're done pumping down, so you'll be unsure of leaks and moisture without it.

    Someone above mentioned removing the vacuum pump and hoses prior to releasing the refrigerant. I wouldn't do that, the system will suck in air as soon as you do. You should: vacuum down as I described above, valve off and watch the micron gauge, if everything is good then release the refrigerant. After that, replace the valve core and remove the tooling. You'll lose a very minute amount of refrigerant this way, rather than sucking in air, so long as your micron gauge is rated to be exposed to the pressure and refrigerant. If it isn't, just add another ball valve to protect it when you release the refrigerant.

    If you don't want to spend $500 on the tools I listed above, just install and wire the indoor and outdoor units, run the drain, and run the line set but keep the ends unconnected and covered up. Then find an HVAC dude that likes sidework and throw him some cash to do the four flare connections, vacuum, and start the unit.

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