Do I Have To Install All Air Handlers For My Multizone HVAC Unit Before Using It? - Ask The Expert Episode 312

Today's question is from Tom.

"Hey Dan-the-Man. Can I buy a MRCOOL 4 zone air handler DIY system, hook up only two indoor wall mount units now, and the other 2 at a later time?"

Yeah, you can do that. You just have to be sure that you are using at least 50% of the capacity of the condenser. So don't only have a 12K air handler running on a 36K condenser.

As long as it is using it properly, that should be fine. People do that all the time.

12 comments (view/add)
  • Tony
    Tony
    Posted on 7/21/2022

    HI Dan -

    I bought a MR Cool DIY 24k unit package with 2 heads (12k + 12k) last year through you all. I installed one head and it's worked great. I just finished an addition on our building and want to add the second head.

    The manual covers a scenario where you do the install where the unit is brand new. The order is 1) Connect refrigerant lines to the head, 2) Connect lines to the Condenser 3) Open the valves to that line 4) Open the king valve.

    Since the unit has already been in use, the king valve is already open. I have attached the head but didn't attach the lines yet.

    In this scenario should I turn the unit off, then close the king valve and then proceed? Is there anything else I should know?

    Thanks

  • Rebekah Muller
    Rebekah Muller from Ingrams
    Posted on 10/17/2022

    Yes, turn the unit off and close the king valve before you continue installing other air handlers.

  • Preston
    Preston
    Posted on 7/10/2022

    Hi Dan, I’m from NJ, I did what you said not to do but just saw this video where you said not to do what I did. I installed a 36K multi zone unit using only one 12K Air Handler and and then tried to add another two days later, now I’m receiving a P6 error code. Is there anyway to fix this?

    Thanks in advance
    Preston

  • Dan Danowski
    Dan Danowski from Ingrams
    Posted on 7/19/2022

    Probably not. You should contact MRCOOL customer service.

  • Don Brown
    Don Brown
    Posted on 6/24/2022

    Hello, If you have a MrCool Multi 4 zone 36K currently with two heads, a 24K and a 12K , can you add another zone 9K, knowing that you will not be using the 24K zone while using the 12K and the 9K?

  • Dan Danowski
    Dan Danowski from Ingrams
    Posted on 7/19/2022

    Yes.

  • David Smith
    David Smith
    Posted on 6/23/2022

    How do I ask a question ?

  • Dan Danowski
    Dan Danowski from Ingrams
    Posted on 7/19/2022

    Just like that.

  • Johncap523
    Johncap523
    Posted on 6/21/2022

    Wait, I have a 28k condenser and a 12k and 9k head. One is in a hot space the other in a very cool space so they’ve yet to ever both run at the same time since they have to both be running in the same mode, so often I’m only running a 9k head.

  • Rebekah Muller
    Rebekah Muller from Ingrams
    Posted on 8/11/2022

    While it may technically work, it could negatively affect the operation of the unit over time.

  • Bob DAgostino
    Bob DAgostino
    Posted on 6/21/2022

    I have a 24K BTU from you guys and it great so far. My main question is keeping the unit clean outside and in.
    Thanks
    Bob
    Fishkill NY

  • Rebekah Muller
    Rebekah Muller from Ingrams
    Posted on 8/11/2022

    Make sure that you're cleaning the filters routinely. There are also mini-split cleaning kits that can be purchased on different sites that can help keep your system clean. Many mini-splits also have a self-cleaning mode that ensures the cleanliness of your unit.


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