What replaced the Carrier 25VNA4?
Checked against 25VNA4 Infinity Variable Speed Heat Pump with Greenspeed Intelligence — Product Data, September 2026.
The 25VNA4 is an R-410A heat pump — Carrier's Infinity tier, variable-speed. R-410A equipment stopped being manufactured after 31 December 2024, so there is no new one of these to buy — but that does not mean your only option is a whole new system.
The model Carrier points you at
The guide maps the R-410A Infinity heat pumps to three Puron Advance models as a group. It does not pair them one to one.
The copper you already have
What the 25VNA4 was installed with, size by size. The successor’s own diameters have not been read yet, so this page cannot compare them for you.
| Model | Capacity | Liquid line OD | Suction line OD |
|---|---|---|---|
25VNA424 | 2 ton | 3/8" | 3/4" |
25VNA436 | 3 ton | 3/8" | 7/8" |
25VNA448 | 4 ton | 3/8" | 1-1/8" |
25VNA460 | 5 ton | 3/8" | 1-1/8" |
Whether your indoor coil, your copper and your furnace can stay is a Carrier rule rather than a rule about this model: the Carrier rules page states all three, with the documents behind them.
A like-for-like R-410A outdoor unit, labelled "For Service Only", is still a legal option in most states and keeps your existing coil — the phase-out guide sets out when that route closes .
How Carrier listed the 25VNA4
| Refrigerant | R-410A |
|---|---|
| Tier | Infinity |
| Compressor | variable-speed |
| Region | All regions |
| Coastal option | Not listed |
What the documents say about this model
ManufacturerThis heat pump meters refrigerant two different ways depending on which way it is running: an electronic expansion valve in heating, a thermostatic expansion valve in cooling. Nothing else on this site carries both, and it is a reason the unit is fussier about a clean, correctly charged line set than a single-stage air conditioner is.
ManufacturerCarrier's own instruction is that the sizing method depends on which load leads. Where cooling is the primary load, size it as any other air conditioning system; where heating leads, the maximum size comes off the heating chart instead. A heat pump replacing a heat pump is not automatically the same tonnage as the box it replaces.
ManufacturerThe maximum liquid line is 3/8 inch at all four capacities. The vapour line is 3/4 inch at 2 ton, 7/8 inch at 3 ton, and 1-1/8 inch at 4 and 5 ton.
Where the mapping comes from
DistributorCarrier Enterprise's 2025 equipment transition guide lists the 25VNA4 as an R-410A Infinity-tier heat pump: a variable-speed unit, sold for all regions. No coastal option is listed. The guide's Puron Advance column for this row is the 27VNA3.
Read next
- Check your own swap against the 27VNA3 Your coil and your line diameters, against what Carrier publishes for the unit you are being quoted.
- The Carrier rules, with sources All three answers for the range, and every document behind them.
This is a starting point, not an approval. Everything here is read from published manufacturer documents and dated, but only the licensed contractor who signs your installation can approve a specific system for your home and your local code. Take the citations on this page to them and ask.