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HVAC replacement cost calculator

There is no published index of what a system replacement costs, so this does not pretend to know. It gives you the line items a real bid is built from and totals whatever you put in them.

Line items

10rows

What a real bid is built from

Typical labour share

20–35%

Of an installed price

Margin range

10–40%

Owner-operator to flat-rate shop

25C credit

expiredafter 2025-12-31

Do not budget for it in 2026

Thermal-toned new condenser beside an old one
The new unit is one line on the invoice; the other lines decide the number.

Why there is no average

Search results are full of confident national averages for replacing a system. They are aggregations of lead-generation form data, not a price index — nobody publishes one, because the same job costs wildly different amounts depending on whether the line set can be reused, whether the flue needs a liner, whether the panel has room for a heat pump, and what the shop's overhead is.

So this tool asks for your numbers. Fill it in twice — once with what you think the job involves, once with a contractor's bid broken out — and the gap tells you what to ask about.

Where the money usually goes

Line items and the questions each one should raise
Line itemWhat to ask
EquipmentWhich model numbers, and what is the AHRI reference for the matched pair?
LabourHow many technician-hours, and how many people on site for how long?
Line setReused or replaced? A reused set on a new refrigerant needs a documented flush.
Duct modificationsWas static pressure measured before the bid, or is the duct assumed fine?
ElectricalDoes a heat pump conversion need a panel or service upgrade? Who is pulling that permit?
PermitIs a mechanical permit included, and who schedules the inspection?
DisposalWho recovers the refrigerant from the old unit, and is the recovery documented?
Overhead and marginNot a question — but it is why two honest bids differ by thousands.

The two dates that move the price

The federal credit has lapsed

The Energy Efficient Home Improvement Credit (25C) could be claimed for improvements made through 2025-12-31 — up to 30% of qualified expenses, capped at $2,000 a year for heat pumps and $1,200 for other qualifying property. Any bid that still shows a federal credit line for work done now is wrong. Utility and state rebates are separate and often still live — check yours directly.

The second date is 2028-12-18: gas furnaces manufactured on or after it must be at least 95% AFUE, against 80% today. Condensing furnaces need PVC venting and a condensate drain, which is real money in a house that currently vents into a masonry chimney. If that work is coming anyway, doing it once is cheaper than doing it twice.

Reading a bid against your build-up

A bid far below your total usually means something is missing — no permit, no duct work, a reused line set on a system that should not have one, or equipment that does not match. A bid far above it is not automatically wrong; a company with real dispatch, a warehouse and a warranty department carries overhead that an owner-operator does not. Ask which row the difference sits in.

Before any of it, confirm the capacity being quoted is the capacity the house needs. The Manual J worksheet takes twenty minutes and has saved people from paying for a ton they did not want.

Sources: IRS, Energy Efficient Home Improvement Credit (read 2026-09-04) · 10 CFR 430.32(e)(1)(iii) (read 2026-09-04)

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