A new Lennox furnace typically costs $4,000-$8,500 installed, with an average near $6,000 for a standard gas model and straightforward replacement. The final price depends mainly on furnace size, efficiency, Lennox product tier, labor rates, and whether venting, ductwork, or electrical connections need changes.
| Item | Low | Average | High | Notes |
|---|---|---|---|---|
| Installed Lennox furnace | $3,500 | $6,000 | $10,500+ | Equipment and ordinary replacement labor |
| Furnace equipment only | $1,500 | $3,200 | $6,000+ | Varies by model, capacity, and efficiency |
| Replacement labor | $1,000 | $1,800 | $3,500 | Higher for extensive vent or duct changes |
| Typical gas furnace capacity | 40,000 BTU | 60,000-80,000 BTU | 120,000 BTU | Correct sizing requires a load calculation |
Assumptions: U.S. prices for a gas furnace, standard residential replacement, existing compatible ductwork, and no major code upgrades.
What a new Lennox furnace costs installed
For a like-for-like replacement, many homeowners pay $4,000-$7,000 for a basic or midrange Lennox gas furnace, including removal of the old unit and standard installation. A high-efficiency or premium communicating system can raise the installed total to $7,000-$10,500 or more. Costs in high-labor markets and jobs requiring extensive modifications may exceed that range.
A practical planning figure is about $6,000 for a standard Lennox replacement, before unusual duct, venting, or electrical work. The estimate assumes one furnace, an accessible mechanical area, and no heat-pump or air-conditioning equipment bundled into the job. A furnace-only quote should not be compared directly with a quote that includes a new thermostat, air conditioner, or extensive duct repairs.
Equipment prices alone commonly fall around $1,500-$6,000, depending on series, capacity, and efficiency. Installation adds labor, removal, setup, and testing. A contractor may price equipment differently from online retail listings because the installed quote can include procurement, warranty administration, startup, and service support.
How the furnace, labor, and venting shape the quote
A furnace quote combines the equipment with installation tasks and any required changes to the home. The table gives common ranges for a typical replacement; line items may be bundled rather than shown separately. Costs vary with access, local labor rates, and whether existing connections meet current requirements.
| Quote component | Typical range | Pricing basis | What it covers |
|---|---|---|---|
| Lennox furnace | $1,500-$6,000 | $1,500-$6,000 per unit | Gas furnace, capacity, and product tier |
| Installation labor | $1,000-$2,500 | $75-$150 per hour | Removal, placement, connections, startup |
| Venting and flue work | $200-$1,200 | $200-$1,200 per job | Adaptation or replacement of vent components |
| Thermostat and controls | $100-$700 | $100-$700 per system | Basic thermostat or compatible communicating control |
| Disposal and delivery | $100-$450 | $100-$450 per job | Old equipment removal and equipment handling |
| Duct or electrical changes | $200-$2,000+ | Scope-dependent | Repairs, wiring, condensate, or transition adjustments |
Labor and equipment usually make up most of the total, while venting and duct changes explain many quote differences. For labor, a rough calculation is . A basic changeout may take a two-person crew about 6-10 hours; a complicated conversion or difficult access can require additional time.
Which Lennox series and AFUE rating change price
Lennox offers multiple furnace tiers, and model availability varies by region. Entry-level models generally cost less and use simpler controls. Midrange options may add two-stage heating or a variable-speed blower. Premium models can include higher efficiency, modulating heat, and communicating controls that coordinate with compatible Lennox equipment.
Standard-efficiency gas furnaces near 80% AFUE may suit homes with appropriate venting and local code approval. High-efficiency models commonly reach roughly 90%-98% AFUE and use sealed-combustion venting; installation may require PVC exhaust piping and a condensate drain. Equipment and installation for a high-efficiency model can add roughly $800-$2,500 compared with a basic replacement, depending on the home and model.
Compare the complete installed price and warranty, not just the AFUE number or model label. A higher AFUE rating can reduce fuel use, but the savings depend on climate, utility rates, heating habits, and the old furnace’s condition. Ask the contractor to identify the exact model number, AFUE, blower type, staging, thermostat included, and warranty terms in writing.
How furnace size and home ductwork affect estimates
Residential Lennox furnaces commonly range from about 40,000 to 120,000 BTU per hour. A small, well-insulated home may need less capacity than a large, drafty home in a colder climate. Capacity should be selected using a room-by-room load calculation rather than copied from the old furnace’s nameplate; an oversized unit can cycle frequently and may not maintain even comfort.
Moving from a 60,000-BTU unit to a properly sized 80,000-BTU model may increase equipment pricing by about $200-$700, but model availability and efficiency can matter more than capacity alone. A replacement that also needs a larger return-air opening, supply transition, or gas-line adjustment may add $300-$1,500. Extensive duct repair or redesign can add $1,000-$4,000 or more.
Ask whether the estimate includes a documented sizing calculation and a duct inspection. A high-efficiency furnace also needs a suitable condensate route and correctly installed intake and exhaust piping. If the furnace is in an attic, crawl space, or tight closet, limited access can add labor even when the equipment specification stays the same.
What installers charge across U.S. regions
Local labor and permit requirements affect the installed Lennox furnace price. As a broad comparison, replacement quotes in lower-cost rural and Southern markets may be 5%-15% below a national midrange estimate. Large coastal cities and parts of the Northeast can run 15%-30% higher because of higher labor rates, dense housing, access constraints, and code requirements.
For the same standard furnace and uncomplicated installation, a $6,000 estimate in a moderate-cost market might translate to roughly $5,100-$5,700 in a lower-cost area or $6,900-$7,800 in an expensive metro. These are directional comparisons, not fixed regional price lists. State and city rules, contractor availability, and the precise equipment package can shift the amount substantially.
Compare quotes from contractors serving the same local market and request identical equipment specifications. Confirm whether the price includes permits, inspections, haul-away, startup testing, and any required combustion or airflow checks. Regional incentives can also change net cost, but eligibility and program funding should be confirmed with the utility or local authority.
How long a furnace replacement takes and labor covers
A straightforward replacement commonly takes 6-10 hours of on-site work for a two-person crew. A contractor typically removes the old furnace, prepares the base, connects gas and electrical lines, adapts the supply and return plenum, installs venting, and tests the new system. A complex job may take 1-2 days if vent routes, duct connections, wiring, or condensate drainage need substantial changes.
Typical labor charges of $1,000-$2,500 reflect crew time, local wages, insurance, travel, and business overhead. Some estimates instead quote a fixed installation price, which makes an hourly figure difficult to isolate. Emergency or after-hours work may add $150-$500 or more, especially during a cold-weather breakdown when contractors have limited availability.
Check that the labor scope includes safe startup and operating checks, not just setting the furnace in place. The written quote should specify who handles permits, old-unit removal, thermostat wiring, vent connections, and cleanup. Ask whether extra work requires approval before it is performed and how the contractor prices additional labor.
When add-ons push a Lennox quote higher
Replacing a furnace can reveal problems that were not visible during an initial estimate. New PVC venting for a high-efficiency model may cost $300-$1,200 when the route is short, while a longer or difficult route can cost more. A condensate pump or drain adjustment may add $100-$400. A compatible thermostat can cost $100-$700 installed, depending on controls and wiring.
Other potential additions include a gas-line change at $200-$800, electrical updates at $150-$600, and duct transition or repair work at $300-$2,000. Permit and inspection charges often fall around $50-$400, but local fees and requirements differ. If the existing furnace is in a difficult-to-reach location, access work or extra handling can add several hundred dollars.
Separate required code or safety work from optional comfort upgrades on the estimate. A contractor should explain why a vent, gas connection, or duct modification is necessary and show the related charge. A new air conditioner, humidifier, air cleaner, or zoning system is a separate scope; bundling may reduce labor overlap, but it also increases the total project price.
Where homeowners can trim furnace replacement spending
Keeping compatible ductwork, gas piping, and vent routes can avoid unnecessary construction costs. If the existing furnace location works and the new unit has a suitable footprint, a like-for-like replacement may keep labor near the lower end of the range. Homeowners can also ask for separate prices for a basic thermostat and premium controls rather than assuming an upgraded control is required.
Request at least three itemized quotes and compare the same Lennox model, capacity, AFUE, staging, thermostat, warranty, permit, and disposal terms. A quote that is $1,000 lower may omit venting, startup, or code work, while a higher bid may include a longer labor warranty or additional duct repairs. Comparing scope prevents a low initial number from turning into a larger change order.
Choose the least expensive system that meets the home’s measured heating load and local requirements. Avoid paying for premium communicating controls or very high efficiency solely because they are available; estimate the likely fuel savings against the price premium. Scheduling replacement before the furnace fails may also provide more time to compare bids and avoid emergency or peak-demand charges.
Repair can be less expensive when the furnace is relatively young and the problem is limited to a replaceable component. Common repairs may cost $150-$800, while major heat-exchanger or control-board work can approach $1,000-$2,500. For an older unit with recurring failures, compare repair cost and expected remaining service life with a full replacement estimate rather than relying on age alone.