A Lennox SLP99V furnace typically costs about $8,000-$14,000 installed, with a common project landing near $10,500 for a straightforward replacement. The final price depends on furnace capacity, local labor, venting and condensate work, and whether the installation requires duct, electrical, or control upgrades.
| Item | Low | Average | High | Notes |
|---|---|---|---|---|
| Furnace equipment | $4,000 | $5,500 | $7,500 | Equipment-only estimate; model and dealer pricing vary |
| Installed furnace replacement | $8,000 | $10,500 | $14,000 | Existing gas and vent connections generally usable |
| Installed furnace with significant upgrades | $11,000 | $14,000 | $17,000+ | May include venting, drainage, electrical, or duct changes |
| Typical furnace capacity | 60,000 BTU | 80,000-100,000 BTU | 120,000 BTU | Correct sizing depends on a home heat-load calculation |
What a Lennox SLP99V Furnace Costs Installed
The SLP99V is a premium, high-efficiency gas furnace with variable-capacity operation and a variable-speed blower. For a standard replacement, homeowners commonly receive installed quotes of $8,000-$14,000, including the furnace, removal of the old unit, routine installation labor, and basic startup checks. A typical quote is around $10,500-$11,000 in a market with average labor rates.
Equipment alone may run approximately $4,000-$7,500 before installation. The wide range reflects furnace capacity, dealer markup, local availability, and included controls or accessories. The SLP99V is a 99% AFUE-class product, but availability can vary by market and model year; a dealer may quote a current equivalent if the specific model is not stocked.
A normal replacement with no major system changes is most likely to fall near the middle of the installed range. A finished basement, difficult access, or required vent and drain work can move the total toward the high end. Assumptions: U.S. home, existing natural-gas service, standard access, and no major duct replacement.
How Furnace Equipment, Labor, and Venting Shape the Quote
Installation proposals bundle several charges, so comparing the total alone can hide differences in scope. A written quote should identify equipment, labor, disposal, venting, drainage, controls, startup, and warranty terms. The following ranges are common planning estimates, not fixed manufacturer prices.
| Quote component | Typical price | What it may include | Cost driver |
|---|---|---|---|
| Furnace equipment | $4,000-$7,500 | SLP99V furnace and standard included parts | Capacity, dealer pricing, and availability |
| Installation labor | $1,500-$3,500 | Removal, connections, setup, and testing | Access, crew time, and local rates |
| Venting and condensate | $300-$1,500 | PVC vent adjustments, drain line, and pump if needed | Route length and existing configuration |
| Controls and accessories | $250-$1,200 | Compatible thermostat, filter cabinet, or wiring changes | Existing controls and system compatibility |
| Removal and disposal | $150-$500 | Hauling away the old furnace and job debris | Local disposal charges and access |
| Permit and inspection | $75-$500 | Local mechanical permit and inspection fee | Municipality and project requirements |
Some contractors combine these items into a single installed price. Others list a low base price and add charges for a new vent route, condensate pump, filter cabinet, or permit. Ask whether the price includes startup, combustion checks, thermostat setup, and removal of the old equipment.
Labor and system modifications, rather than the furnace cabinet alone, explain much of the difference between competing quotes. For example, 12-20 installation hours at $100-$175 per hour represents roughly $1,200-$3,500 in labor before materials and overhead.
Why 60,000 Versus 120,000 BTU Changes the Price
Capacity is a major equipment-price variable, but a larger furnace is not automatically the correct or more comfortable choice. Common residential sizes range from about 60,000 to 120,000 BTU input. Larger units generally cost more, and oversizing can cause short cycling or reduce comfort even when the furnace has advanced modulation.
As a rough budget distinction, equipment for a 60,000-80,000 BTU configuration may be near the lower part of the equipment range, while a 100,000-120,000 BTU configuration may add several hundred dollars or more. Exact differences depend on the available model and dealer quote. A heat-loss calculation should determine the capacity rather than the size of the old furnace alone.
Other technical details can alter installation scope. A vent route longer than roughly 20-30 feet, multiple elbows, or a new route through finished space may add $300-$1,500 or more. A condensate line without a suitable drain can require a pump, often adding $150-$450 installed. A furnace installed in a tight closet or attic can also require extra labor for safe removal and positioning.
Capacity, vent length, and drain access are practical quote checks because each can change both equipment selection and installation hours. Ask the contractor to document the heat-load method, proposed BTU input, vent material and route, and condensate disposal plan. Assumptions: added costs are incremental estimates and may overlap when a contractor prices a complete modification package.
Which SLP99V Installation Choices Can Lower the Price
Keeping a suitable existing vent route, drain, gas connection, and electrical circuit can avoid unnecessary work. That does not mean old components should be reused automatically; the installer must confirm they meet the new furnace instructions and local code. Request a line-item explanation for any proposed replacement of nearby equipment or piping.
Compare at least three written quotes with the same furnace capacity and scope. Check whether each includes the thermostat, filter cabinet, permits, disposal, startup, and warranty labor. A quote that is $1,000 lower may omit a required vent conversion or provide a shorter labor warranty, while two similar totals may differ in useful commissioning and follow-up service.
Do not pay for a larger furnace or premium add-ons without a specific reason. If the existing thermostat is compatible, a new control may not be needed; if duct leakage is the real comfort problem, a furnace upgrade alone may not solve it. Scheduling outside the coldest emergency periods can also give more time to compare bids and avoid expedited service charges.
The most reliable savings usually come from controlling scope and comparing equivalent proposals, not choosing an undersized unit or skipping code-required work. Ask whether a repair is still economical if the present furnace has a single failed component and otherwise has a sound heat exchanger. Conversely, repeated major failures can make replacement more sensible than continued repair.
How Regional Labor Rates Shift Installed Furnace Prices
Regional labor and operating costs can move an installed SLP99V quote substantially. In lower-cost rural and smaller-market areas, a straightforward replacement may come in roughly 10%-15% below a national middle estimate. Large metropolitan areas and high-cost coastal markets can run 15%-30% above it, especially when contractor schedules are full or access is difficult.
Climate and local building practices matter too. Cold-weather markets may have stricter expectations for vent termination, condensate protection, or heating-system commissioning. Older urban housing can require longer vent runs or work in narrow basements. These conditions affect the job itself, not merely a regional price premium.
For planning, a $10,500 midrange installation could translate to about $8,900-$9,500 in a lower-cost market, or approximately $12,100-$13,700 in a high-cost market before unusual upgrades. These are broad comparison figures; a local written estimate is necessary because nearby cities can have different permit charges and labor availability.
Regional percentages are useful for a first budget, but the actual vent route, access, and contractor scope determine the quote. Compare local bids rather than applying a national average as a guaranteed price. Assumptions: percentages compare similar equipment, replacement scope, and warranty coverage.
How Long SLP99V Replacement Labor Usually Takes
A direct furnace swap often takes one working day, or about 8-12 crew hours, when the old unit is accessible and the venting and connections are compatible. A two-person crew may complete removal, setting, connections, and startup within that window. More complex work can extend the job to 1-2 days or approximately 12-20 labor hours.
Labor is commonly budgeted at about $100-$175 per hour, although most homeowners receive a fixed project quote rather than an hourly bill. A contractor may charge more for emergency scheduling, work in a cramped attic, or installation that requires several trades. Ask whether the crew will perform a complete test before leaving and whether follow-up adjustment is included.
Installation duration is not a substitute for quality. Modulating furnaces require correct setup and compatible controls; the installer should verify operation across the required stages or capacity range, confirm airflow, and check venting and condensate drainage. A proposal that promises an unusually fast installation should still explain commissioning and inspection steps.
One day is a reasonable expectation for a simple replacement, while vent or duct changes can add time and labor charges. Confirm whether the quoted labor includes removal, reconnecting the thermostat, startup, and cleanup rather than assuming each task is covered.
What Three SLP99V Quote Scenarios Can Look Like
Real proposals depend on the home, but these examples show how scope can produce different totals. They assume standard natural-gas service and are intended as budgeting illustrations, not guaranteed local bids.
| Scenario | Scope and labor | Estimated total | Why it costs this much |
|---|---|---|---|
| Basic 60,000-80,000 BTU replacement | 10-12 crew hours; existing vent, drain, and controls retained where approved | $8,000-$9,800 | Limited modifications and lower equipment capacity |
| Typical 80,000-100,000 BTU replacement | 12-16 crew hours; minor vent and condensate adjustments | $9,800-$12,800 | Common installation scope with routine accessories |
| Complex 100,000-120,000 BTU project | 16-20 crew hours; new vent route, drain pump, or control work | $12,500-$17,000+ | Higher capacity and additional installation labor |
A useful cross-check is the implied price per heating capacity, but that figure should not decide the purchase: the furnace is not priced like a commodity per BTU. A complete quote includes labor, safety checks, permits, and the conditions required to install the equipment correctly. Request an itemized breakdown if a quote sits far outside these ranges.
The basic-to-complex spread is mainly a scope difference, not simply a different markup on the same furnace. A project with duct repairs or extensive electrical changes may exceed the high example, so those items should be specified separately where possible.
When Venting, Ductwork, and Permits Add Charges
High-efficiency furnaces produce condensate and use venting arrangements that can differ from an older furnace. Reusing a chimney or vent is not always allowed or suitable. A new PVC route, wall or roof termination, and related sealing may add about $300-$1,500; longer or difficult routes can cost more. Condensate drainage work commonly ranges from $100-$600, depending on whether a gravity drain is available or a pump is needed.
Ductwork can add a larger, separate expense. Minor transitions or sealing may cost $200-$800, while substantial duct repair or replacement can add $1,000-$5,000 or more. These costs should not be hidden within a vague “installation” line, particularly if the work affects only a few supply or return connections.
Permit fees often fall around $75-$500, with inspection requirements set locally. A permit may be required for furnace replacement, gas work, vent changes, or electrical changes. Ask the contractor to identify who obtains the permit and whether the quoted total includes fees and inspection corrections.
Ask for the exact reason and measured scope behind every vent, duct, or code-upgrade charge. A necessary modification can protect safe operation and approval, but unrelated upgrades should be separated from the furnace installation so the homeowner can compare them clearly.