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R22 to R410a conversion

When converting a system from R22 to R410a and using the same line sets is there a proper procedure to use so I done contaminate the new refrigerant.


  • Tom Blackwell_2
    Tom Blackwell_2 Member Posts: 126

    All of the old oil will have to be removed before evacuation. Denatured alcohol works fairly well and there are several flushing agents available also. Blow it through with nitrogen or co2. Then evacuate to at least 500 microns and be sure it holds at this level before charging.
  • Techman
    Techman Member Posts: 2,144

    Hay radmix,I'm assuming your changing out the ac unit and reusing only the line set.Since you've recovered the old r22 it's not the new r410a being "contaminated" that you should be worried about.The concern is the old mineral  oil being left behind in any low spots in the old lineset.There are several "flush kit's " on the market for purging/flushing out the mineral oil.But if the old lineset is down hill all the way,then MOST of the minoil is drained anyway.But check w/the mfrg of the new equipment for their procedure to cover the warranty.The new POE oil doesn't get along w/the minoil,the new r410a doesn't get along w/the minoil.Happy 4th to you and yours
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