Ductless Mini Split startup

Discussion in 'HVAC' started by python01, Nov 14, 2017.

  1. Nov 14, 2017 #1





    Apr 25, 2007
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    I have installed a brand new 3 zone mini split ductless system for my addition. All the lines are in place and all electrical is connected. All that is needed is to properly test for leaks and pressurize/start up the system.

    How much time would this take if there are no issues and how much would I expect to pay for such service? I had someone quote $800.00 for this which I find ridiculous but maybe I am wrong?

    Could anyone recommend a technician in my area who would do this job for a decent price?

    Or can anyone point me to online tutorial how to do this myself? I think it would be cheaper to buy the tools than $800.

    I am in Hamilton, Ontario.
    nealtw likes this.
  2. Nov 22, 2017 #2




    Well-Known Member

    May 26, 2014
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    First , do you have all the copper lines connected ? Does the length each set of lines fall within the factory parameters ? If so , you should have sufficient refrigerant , in the factory charge , inside the condensing unit .

    If not you may need to adjust the refrigerant charge . Which a DIY'er may not be able to do . The 2 units I installed , I purposely kept the lines to the recommended length .

    Next you need to vacuum the copper lines down , to a " high vacuum " . In the States , you can often " borrow " a vacuum pump from the local auto parts store . Technicians use a micron " gauge " to read the vacuum " numbers " .

    If it holds vacuum properly , after the " gauges " have been valved off & vacuum pump turned off , you need to pressure test the system .

    This is usually done with dry nitrogen . This requires a " bottle " of compressed nitrogen & a regulator .

    If it holds pressure correctly , Vacuum it back down .

    Then , following the factory instructions , open the service valves to allow the refrigerant contained in the condenser unit to flow through the lines and indoor units .

    After the refrigerant has stabilized , I would monitor pressures ( everything off ) as a secondary pressure check .

    Then , power up all the system and check each indoor unit & see if they are operating satisfactory .

    The MS's I have installed all had single indoor units . I have no experience with systems with more than one indoor unit .

    Also , I may have forgot some steps . :-(

    I am not a professional HVAC technician , Although I do hold the first level of EPA card . Which covers me on the MS's I have installed .

    Happy Thanksgiving and best of luck , :)
    havasu likes this.

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