Furnace replacement cost: what your quote includes

One quote says “new furnace.” Another says “complete system.” Both have a large number at the bottom. Before you compare those numbers, find out what each company plans to replace. The word “complete” is doing quite a lot of work there.

A furnace warms air and sends it through ducts, the passages that carry air around the home. A boiler heats water or makes steam for home heating. If your quote covers a boiler, it needs a different price comparison—even if everyone in the house calls it the furnace.

This guide helps you compare the cost of replacing a furnace. The price study below covers gas units. Oil, propane and electric furnaces need quotes for their own equipment and work. Changing the fuel or adding cooling makes it a different job again.

What published furnace prices can tell you

For a dated example, Opinion Dynamics’ 2025 TECH Clean California study gathered these bids during June and July 2024:

Work quoted in the study	Average bid before discounts or aid
Gas furnace only, 39 bids	$8,415
Gas furnace plus central air conditioning, 26 bids	$17,588

These were quotes, not final paid bills. The table covers California homes with one heating-and-cooling system. Several bids could come from the same home. Contractors could choose different equipment and work, so the two averages are not a matched comparison. Subtracting them would not tell you what adding air conditioning costs.

Few bids listed each cost on its own. The study does not show that every total covered the same taxes, removal, permits or work around the unit. Permits are local approvals needed for some work.

Treat this as one old price snapshot, not a national 2026 price range or a test of whether your quote is fair. Current local quotes for the full job are what you can use to plan your spending.

Start with what stays and what goes

A furnace-only job replaces the heating unit. A combined job may also replace the outdoor air conditioner, or AC, and the indoor cooling coil. That coil is the part that takes heat out of the air during cooling.

Have the contractor name every part they plan to keep or replace. “Full system” is not a parts list.

You may be able to keep the old cooling equipment. The installer needs to check that it works with the new furnace and its airflow. Get a furnace-only price if that is a workable option, then compare it with the combined job.

Do the same with new controls, air-cleaning products and service plans. Some work may be needed for the new unit to work as it should. Other items are choices. Each needs a reason and a price.

For example, an offer that includes cooling, a new control and a yearly service plan covers more than a furnace swap. A lower monthly payment does not tell you which of those things you need. Lay out the work first; choose how to pay once the job is clear.

What are you paying for in the furnace itself?

The model name can hide several choices. Three worth keeping apart are heat output, fuel use and how the furnace runs.

Heat output: enough for the home

Capacity means how much heat the unit can supply. The home’s heating load is how much heat it needs under set weather conditions. A load calculation works out that need using details such as windows, insulation and local weather.

Have the installer explain how the chosen model fits that result. Floor area alone is not enough. Neither is the size on the old unit’s label. A past choice does not become the right one by having spent 20 years in the basement.

Fuel input and heat output are different numbers, too. One describes energy going into the unit; the other describes heat it can supply. Use the exact model’s data when comparing them.

Fuel use: read the rating in context

Annual fuel utilization efficiency, or AFUE, is a rating for how much fuel energy a furnace turns into heat. It is shown as a percentage. A higher rating means more of that fuel energy becomes heat under the rating’s test conditions.

It does not include the fan’s power use or heat lost through ducts. It also does not tell you what your whole fuel bill will be.

If a higher-priced model is sold on lower bills, get the savings estimate and what it assumes. Your fuel price, how much heat you use and the work needed to fit the unit all matter. You need those details to judge whether the extra cost makes sense for you.

Heating stages and fan speed

Heating stages describe how the furnace changes its heat output. A single-stage furnace has one heat level while it runs. A two-stage model has low and high heat. A modulating model can make smaller changes in output.

The fan moves indoor air. Its speed is a separate feature. Two heating stages do not tell you the fan’s full speed range or the fuel rating.

Some people value quieter, steadier heat; others want fewer features and a lower price. Have the installer explain what each option would change in your home. A longer model name is not a comfort test.

The work around the unit belongs in the price

A condensing furnace gets extra heat from exhaust, the gases left from burning fuel. As those gases cool, water vapor turns into liquid. That water needs a drain. The model also needs the right venting: the route that takes exhaust outdoors.

Changing to this kind of furnace may mean a new drain route, a pump or changes to the exhaust pipes. The installer should check what your house needs and price that work. Do not assume every old connection can stay—or that every connection must go.

There is one detail worth raising if your furnace and water heater share a chimney. Removing the furnace from that chimney can change what the water heater needs to vent safely. A qualified pro needs to check the remaining setup and include any needed work. This is part of planning the job, not a homeowner pipe project.

Ducts, wiring, fuel connections and access to the space can also affect the work. A unit in a tight attic may need a different plan from one beside a clear basement door. A useful quote shows what the contractor found and how they plan to handle it.

Use this list to find gaps before comparing totals:

Part of the job	What belongs in the written quote
Equipment	Exact models, parts being replaced and parts being kept.
Connections	Needed duct, exhaust, drain, fuel and wiring work; any work left out.
Old unit and local checks	Removal, cleanup, taxes, needed permits and inspections, with who handles them.
Setup	The checks and records you will get when the system is running.
Coverage	Separate terms for parts, repair labor and the installer’s work.
Extras	A price and clear choice for each optional product or paid plan.
Dates and changes	Expected work dates, time without heat and how you agree to added work or cost.

Our guide to comparing heating and cooling quotes helps put those details side by side. The furnace replacement guide follows the job through setup and the final checks.

Read the repair and coverage details too

A new-furnace price makes more sense once the reason for replacement is clear. Get the technician’s findings in writing. If repair is an option, get its price and any limits too.

A discount on a new unit does not tell you what is wrong with the old one. Age alone does not settle the choice either. A second qualified opinion can help with unclear findings. Follow any urgent safety directions; this guide cannot tell you whether your furnace is safe to run.

Then look at the promises that come with the new unit. A parts warranty may pay for a covered part without paying the full repair bill. Labor is the work needed to fix it. Trips, testing or other charges may have their own terms.

The installer’s promise about their work may be separate from the maker’s parts coverage. Get each in writing. Find out whether signing up the product, keeping service records or buying a paid plan affects the offer. Keep the terms that apply to your exact model and home.

Keep the job price separate from the payment plan

Start with the full installed price: the equipment and agreed work, with taxes and fees made clear. Then list any approved help with the bill and when it will arrive. Some local programs cover certain heating work, but applying does not mean your furnace is approved or booked.

Older price guides may still mention a federal tax credit, which reduces tax owed. The Energy Efficient Home Improvement Credit, also called Section 25C, does not cover new equipment put into use after December 31, 2025. That rule was checked on November 5, 2026. Do not subtract this former credit from a new 2026 furnace job. Other programs have their own rules.

If you borrow, compare the full amount you must pay back as well as each payment. Interest is the cost of using borrowed money; fees can add more. Include any deposit and job costs paid outside the loan. Our furnace financing guide explains those choices and dates.

Before you book, you should be able to name what is being replaced, what work is included and what you will pay. Keep the work plan, dates and payment terms together. The paperwork can be dull. Having to guess what you agreed to is much less fun.

The heating and cooling hub brings our related guides together.