# Do existing line sets need replacement for A2Ls, or just new fittings/cleaning? What are typical pass/fail scenarios in…

**URL:** <https://home.renovation.reviews/t/do-existing-line-sets-need-replacement-for-a2ls-or-just-new-fittings-cleaning-what-are-typical-pass-fail-scenarios-in/19950>\
**Category:** Trade Talk\
**Created:** [August 4, 2025, 3:15pm UTC](https://home.renovation.reviews/t/do-existing-line-sets-need-replacement-for-a2ls-or-just-new-fittings-cleaning-what-are-typical-pass-fail-scenarios-in/19950 "2025-08-04T15:15:43Z")\
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**Author:** ![reno\_questions](https://home.renovation.reviews/user_avatar/home.renovation.reviews/reno_questions/32/2758_2.png) [@reno\_questions](https://home.renovation.reviews/u/reno_questions)\
**Post date:** [August 4, 2025, 3:15pm UTC](https://home.renovation.reviews/t/do-existing-line-sets-need-replacement-for-a2ls-or-just-new-fittings-cleaning-what-are-typical-pass-fail-scenarios-in/19950/1 "2025-08-04T15:15:43Z")

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Do existing line sets need replacement for A2Ls, or just new fittings/cleaning? What are typical pass/fail scenarios installers are seeing?

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**Author:** ![Tim\_Michael1](https://home.renovation.reviews/user_avatar/home.renovation.reviews/tim_michael1/32/6294_2.png) [@Tim\_Michael1](https://home.renovation.reviews/u/Tim_Michael1)\
**Post date:** [August 14, 2025, 8:32am UTC](https://home.renovation.reviews/t/do-existing-line-sets-need-replacement-for-a2ls-or-just-new-fittings-cleaning-what-are-typical-pass-fail-scenarios-in/19950/2 "2025-08-14T08:32:09Z")

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If your copper lines are clean, you can reuse them, but make sure all the fittings are A2L-rated and that the lines are properly purged. Usually, failures happen because of old valves, contamination, or if the brazing/purging wasn’t done right.

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**Author:** ![Tim\_curtis](https://home.renovation.reviews/user_avatar/home.renovation.reviews/tim_curtis/32/2766_2.png) [@Tim\_curtis](https://home.renovation.reviews/u/Tim_curtis)\
**Post date:** [August 14, 2025, 10:06am UTC](https://home.renovation.reviews/t/do-existing-line-sets-need-replacement-for-a2ls-or-just-new-fittings-cleaning-what-are-typical-pass-fail-scenarios-in/19950/3 "2025-08-14T10:06:54Z")

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Installers usually keep existing line sets for A2Ls if copper size matches the new unit spec walls are clean after flushing pressure tests pass and flare or braze joints are updated Failures are most often from internal corrosion oil sludge kinks punctures or undersized tubing that would cause pressure drop or capacity loss