QUOTE LINE ITEM · LAST CHECKED NOVEMBER 4, 2026
Line set and refrigerant piping on a heat pump quote: what it should say
Quick answer
The line set is the pair of copper refrigerant pipes between the outdoor and indoor units. A quote should say whether it is new or reused, roughly how long it is, how it will be run and covered, and that it will be pressure-tested and evacuated before the system is charged.
What a complete quote states
- New or reused line set, and if reused, how it will be checked and cleaned.
- Approximate length and route, and whether line hide (a cover) is included outside.
- The refrigerant the new system uses (for example R-454B or R-32), and that any additional refrigerant charge for the line length is included.
- Pressure test with nitrogen and vacuum evacuation before charging, recorded at startup.
Red flags when it is missing or vague
- “Line set as needed” or “extra per foot” with no estimate of length.
- Reusing an old line set without saying how it will be checked.
- No mention of pressure testing or evacuation.
- Exposed pipes on a wall you care about, with no line hide in the quote.
Three questions to send the installer
- Is the line set new or reused? If reused, how will you verify it’s suitable for the new refrigerant and free of leaks?
- About how long is the line set, how will it be routed, and is line hide or a cover included?
- Will you pressure-test and evacuate the system before charging, and will I get the startup readings in writing?
Why two quotes differ here
Reusing an existing line set saves labor and copper, and is sometimes fine. It depends on the pipe size, condition and the new equipment’s requirements. A quote that reuses the old line set can be cheaper for a legitimate reason, or because a step is being skipped. Ask.
Ductless (mini-split) quotes differ most here: each indoor head needs its own line set, so the number and placement of heads drives length, wall penetrations and line-hide costs.
Refrigerant: what changed and what didn’t
EPA’s Technology Transitions rule limits new residential air conditioning and heat pump systems to refrigerants with a global warming potential of 700 or less, for equipment manufactured or imported from January 1, 2025. That is why new systems commonly use refrigerants such as R-454B or R-32 instead of R-410A.
In May 2026 EPA removed the January 1, 2026 installation deadline for systems built from older stock: its sector table now says there is “No installation compliance date for systems where all specified components were manufactured or imported prior to January 1, 2025.” So an R-410A system on a 2026 quote isn’t automatically a problem. Ask which refrigerant and why, and confirm the outdoor and indoor units are a matched system.
Carrier says its R-454B equipment “is not a drop-in replacement” for R-410A, and that line sets need not be replaced “as long as the lineset meets the current building code.” A 2026 Lennox R-454B installation manual says field piping “shall be pressure tested with an inert gas and then vacuum tested prior to refrigerant charging”, and requires flushing a line set previously used with mineral oil. Efficiency Maine’s installer checklist requires the line set to hold over 600 psig and a vacuum below 500 microns, each for 10 minutes.
Cost
We don’t publish a per-foot price. Ask whether the quoted length is included and what each extra foot would cost.
Sources
- Technology Transitions HFC restrictions by sector (U.S. EPA, page dated August 28, 2026)
- Technology Transitions reconsideration rule fact sheet (PDF) (U.S. EPA, page dated May 2026)
- R-454B (Puron Advance) FAQ (PDF) (Carrier)
- ML15KSPV R-454B heat pump installation instructions (PDF) (Lennox, page dated September 2026)
- Efficiency Maine heat pump installation checklist (PDF) (Efficiency Maine, page dated January 1, 2026)
- Heat Pump Space Heating Permitting & Inspection Checklist (PDF) (New Buildings Institute for the U.S. DOE, page dated October 2024)
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Last checked: . Informational only. This is not financial, tax, legal or professional installation advice, and we do not verify any installer’s work.