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Community and Q&A

Vetting a ductless minisplit contractor

John_Brown | Posted in Mechanicals on

I have been doing extensive research on Ductless units and feel pretty comfortable with what I have for my design. One of the things that perplexes me is that the manufacturers won’t really warranty their units if you purchase them and install them yourself. I have found a few good merchants that seem to know all the nuances of installation but I feel if I were to purchase one, mount/install it, run linesets and THEN hire a professional to do the lineset flare connections, evacuate the system to 500 microns or less, charge the system and then get it running, I probably wouldn’t be eligible for a compressor warranty should something happen. Am I correct in this assumption?

I am hoping Dana might offer some suggestions. I definitely want the system to be properly installed but as I have done my due diligence into the technician side of things (assuming I was going to do the mounting and linesets), it seems to me there are cases where the technician and the manufacturer are pointing their fingers at each other. Basically, it seems that leaks are what cause the system to malfunction or fail.

From what I understand, how do I properly vet the contractor? I’m assuming I can get my hands on the installation docs and run down what I expect. I found a good post from an HVAC guy who said the following (more or less):

-Make sure the flares are done correctly (the 410a Refrigerant has a specific flare angle required)
-Make sure the flare nuts that come with the equipment is used NOT the lineset flarenuts
-Factory flares in the linesets are likely inferior
-Use some oil on the threads
-Tighten to torque specified
-Install a surge protector on the system

Basically, I don’t want to be a person hovering over the technician, but if this is the only way I can keep the equipment warranty intact (because I can’t do it myself), I want to be sure it’s done correctly.

Any thoughts on how to proceed? The site is in SE Idaho. I did see a reference in a previous post to a test on some Mitsu units in Idaho Falls so if anyone knows of a solid Ductless contractor in the area, I would be grateful. I don’t want to quiz a contractor on what kind of flareblock they have in their toolbox but I definitely want the installation to go properly.

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  1. GBA Editor
    Martin Holladay | | #1

    An HVAC contractor is "vetted" using the same methods used to evaluate any contractor. Ask if the contractor is a certified installer under any programs established by minisplit manufacturers. Ask for references and call up customers who have used the contractor. As whether the contractor performs Manual J calculations. Ask which type of modeling software the contractor uses for Manual J calculations. Ask to see a sample Manual J calculation from a previous job. Ask questions about ductless minisplit installations to see whether the contractor's answers pass the "smell" test.

  2. charlie_sullivan | | #2

    I'm not sure how hovering over the technician helps the warranty situation. It seems that if you want a valid warranty you have to purchase and install through normal channels. If you want to do some of the non-technical installation work yourself, you can discuss that with an HVAC company, and you might or might not find one who agrees to work that way.

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