Lennox furnace replacement cost commonly ranges from $4,000 to $9,000 installed, with a typical midrange project near $6,500. The final quote depends on furnace size, efficiency, model tier, labor rates, venting and whether ductwork or electrical work also needs attention.
| Item | Low | Average | High | Notes |
|---|---|---|---|---|
| Installed Lennox furnace | $3,500 | $6,500 | $11,000 | Equipment and standard installation |
| Furnace equipment | $1,500 | $3,500 | $6,000 | Varies by model and capacity |
| Installation labor | $1,200 | $2,200 | $4,000 | Higher for difficult conversions |
| Additional duct or vent work | $300 | $1,200 | $4,000+ | Not included in a basic swap |
What a typical Lennox furnace replacement includes
A standard replacement in an existing home usually costs $4,000-$9,000 for a gas furnace, including the unit, removal of the old furnace, installation, startup checks and a basic thermostat connection. A straightforward changeout using existing compatible connections tends to fall near the lower end; high-efficiency equipment or a complicated installation raises the total.
A realistic budget for a standard Lennox gas furnace is about $5,000-$8,000. The range assumes a 60,000- to 100,000-BTU unit, average U.S. labor rates, no major duct repairs and ordinary access. Furnace prices are not fixed by brand alone: Lennox model tier, dealer pricing and included warranty or service terms matter.
For a small home, a lower-capacity furnace may cost less than a unit sized for a large or drafty house. A contractor should calculate heat loss rather than simply match the old furnace’s output. An oversized replacement can cycle inefficiently, while an undersized unit may struggle during cold weather.
How equipment, labor, and venting shape the quote
Quotes combine the furnace with labor and any required changes to make the system safe and code-compliant. Ask whether the estimate includes startup testing, permit fees, disposal, thermostat work and taxes; exclusions can make two apparently similar bids difficult to compare.
| Quote component | Typical range | Pricing basis | What changes the charge |
|---|---|---|---|
| Lennox furnace | $1,500-$6,000 | Per unit | Capacity, efficiency and model line |
| Installation labor | $1,200-$4,000 | $75-$150 per hour | Crew size and conversion work |
| Permit and inspection | $50-$500 | Per project | Local jurisdiction and scope |
| Removal and disposal | $100-$400 | Per old unit | Access and local disposal fees |
| Vent, gas, or electrical changes | $200-$2,000+ | Per project | Existing connections and code needs |
Labor is often the largest variable beyond the furnace itself. A basic swap may take a two-person crew 6-10 hours; work involving a vent conversion, gas line adjustment or cramped utility space can take longer. A rough labor estimate follows , but contractor quotes may package labor and overhead rather than list hours separately.
How AFUE rating and BTU size change the price
Two specifications have a strong effect on a Lennox quote: heating capacity, measured in BTU per hour, and annual fuel utilization efficiency, or AFUE. A typical 60,000- to 100,000-BTU unit is common in many homes, but climate, insulation, layout and home size determine the right capacity.
Higher AFUE can add roughly $500-$2,000 or more to equipment and installation. Standard-efficiency options may be near 80% AFUE, while high-efficiency condensing models commonly reach about 90%-98% AFUE. High-efficiency units may require PVC venting, a condensate drain and nearby electrical access, adding about $300-$1,500 when those changes are not already in place.
Capacity changes also affect the quote. Moving from a smaller furnace to a substantially larger unit can mean a different cabinet, gas supply review or duct modifications. An estimate should identify the model number, BTU input, AFUE rating and any proposed changes so the price can be compared on equal terms.
Which Lennox replacement choices can lower the bill
Cost control starts with keeping the project scope clear. If the existing furnace is correctly sized and the vent, gas line and ducts are in good condition, a like-for-like replacement may avoid extensive alterations. The contractor should still verify sizing and inspect connections rather than assume that the old setup is suitable.
Compare complete, itemized quotes instead of choosing by equipment price alone. Request two or three local bids listing the exact Lennox model, labor, permit, removal, thermostat and warranty. A quote that omits vent or duct work may look lower but rise after installation begins. Ask what conditions could trigger extra charges and request written approval before added work.
Where a high-efficiency upgrade requires costly vent or drain changes, compare its installed premium with the expected fuel savings for the home and local gas prices. Avoid paying for a thermostat or accessory that is already compatible. Scheduling during a contractor’s less-busy period may improve availability, though local seasonal discounts are not guaranteed.
How long Lennox furnace installation usually takes
A straightforward replacement generally takes 6-10 hours, commonly completed in one day by a two-person crew. Installation may stretch to 1-2 days if the job includes a new vent route, condensate plumbing, electrical changes, gas piping or duct transitions. A difficult attic, crawlspace or tight basement can add setup and handling time.
Confirm that the quote covers commissioning, not just setting the furnace in place. The crew should verify gas pressure, airflow, ignition, venting and safety controls, then explain the thermostat and filter requirements. If the home needs heat during freezing weather, ask how long the system will be off and whether the contractor can schedule the changeout in a single visit.
When ductwork, venting, and removal add extra charges
Old furnace removal usually adds $100-$400, though some bids include it in the installation price. Replacing a short section of accessible duct may cost $300-$1,000; broader repairs or duct replacement can add $1,500-$5,000 or more depending on layout and access. Vent conversion for a condensing unit may cost $300-$1,500, while a condensate pump or drain connection can add $150-$500.
Get any nonstandard work separated from the base furnace price. Ask the contractor to describe the problem, show which components need replacement and distinguish required code or safety work from optional improvements. A permit can cost around $50-$500 depending on local rules, and required inspections may affect scheduling.
Why Lennox installation prices differ by U.S. region
Labor markets, permitting and contractor demand create meaningful regional differences. A basic installation in a lower-cost rural market may run about 10%-20% below a comparable urban quote. High-cost metro areas and parts of the Northeast or West Coast can come in 10%-25% above the national midpoint, particularly when access is difficult or licensed trade labor is scarce.
Compare bids from contractors serving the same local market and using the same equipment specifications. A $6,000 quote in one region may not include the same permit, venting or warranty items as a $7,500 quote elsewhere. Check whether prices include sales tax, disposal and required code updates before treating a regional difference as a true savings.
When furnace repair costs less than replacement
A Lennox furnace repair may cost $150-$600 for a common service call or minor part, while major repairs such as a blower motor or control board can reach $500-$1,500. Heat exchanger work may cost more and can make replacement the practical comparison, especially if the furnace is older or has recurring failures. Diagnosis fees often run $75-$200 and may be credited toward approved work.
Compare the repair bill with the furnace’s age, safety, and expected remaining service life. For a newer unit with one isolated failure, repair may preserve substantial value. For an older furnace with repeated costly repairs, a replacement quote provides a useful benchmark; ask the technician to explain the diagnosis and whether operation presents a safety concern.