The SLP99V is Lennox’s flagship gas furnace in the Signature Collection. It is designed for homeowners who want the absolute best in efficiency, performance, and comfort. With its modulating gas valve and variable-speed blower, the furnace delivers consistent, even heating while minimizing noisy on-off cycles.
SilentComfort technology and heavy insulation reduce noise to a whisper, while smart compatibility with Lennox’s advanced thermostat and filtration systems make it a perfect fit for modern homes.
| Feature | Specification |
|---|---|
| AFUE | Up to 99% |
| Gas Valve | Fully modulating |
| Blower Motor | Variable-speed ECM |
| Noise Reduction | SilentComfort® technology, insulated blower compartment |
| Smart Controls | iComfort® thermostat, PureAir™ air filtration, zoning and humidifier compatibility |
| Warranty | Lifetime heat exchanger warranty, 10-year parts warranty (with registration) |
| Model | AFUE | Gas Valve / Blower Type | Noise & Comfort | Cost (Installed) | Best For |
|---|---|---|---|---|---|
| Lennox SLP99V | Up to 99% | Modulating + Variable-Speed | Ultra-quiet, precise control | $7,000 to $11,000+ | Ultimate efficiency and comfort |
| Rheem R98MV | Up to 98% | Modulating + Variable-Speed | Quiet with sealed combustion | $6,000 to $10,500 | High efficiency with safety features |
| Trane XC95m / Premier 96 M | Up to 97.3% | Modulating + Variable-Speed | Very quiet, stable heating | $6,500 to $11,500 | Reliable performance and comfort |
The Lennox SLP99V stands at the top of the furnace market for AFUE efficiency, with unmatched quiet operation and premium customization. While Rheem and Trane compete closely, Lennox sets itself apart for maximum efficiency and smart integration.
The Lennox SLP99V typically costs $7,000 to $11,000+ installed.
Price depends on:
Though more expensive than standard furnace models, its efficiency, comfort, and energy savings make it a worthwhile investment for many households.
As with any HVAC system, labor and permitting costs vary by location. High-cost areas like California, New York, and the Northeast generally fall at the top of the price range, while the Midwest and South trend lower.
Because the SLP99V is ENERGY STAR Most Efficient certified, it often qualifies for utility rebates, state incentives, and the federal tax credit for high-efficiency heating equipment, helping offset installation costs.
| Region | Estimated Installed Cost (SLP99V) | Avg Annual Heating Fuel Cost* | Estimated Annual Savings vs. Mid-Efficiency (90 to 94% AFUE) |
|---|---|---|---|
| South | $5,500 to $7,000 | ~$1,100 to $1,400 | $150 to $250 |
| Midwest | $5,800 to $8,500 | ~$1,300 to $1,700 | $200 to $350 |
| Northeast | $6,000 to $9,000 | ~$1,500 to $2,000 | $250 to $400 |
| West | $6,000 to $8,800 | ~$1,400 to $1,800 | $200 to $350 |
*Based on natural gas fuel costs, a 2,000-sq ft home in a typical climate, and moderate heating usage. Actual costs vary with local utility rates and home insulation.
If you move from a mid-efficiency furnace (90 to 94% AFUE) up to the SLP99V (up to 99% AFUE), you will likely see $150 to $400+ per year in fuel savings, depending on your region.
For colder climates like the Northeast and Midwest, the payback is especially strong because the furnace operates for longer periods — so the higher upfront investment can be offset more quickly.
To maximize savings, ensure ducts are sealed, installation is done correctly, and thermostat settings are optimized — inefficiencies elsewhere can diminish the benefits.
With proper maintenance, the SLP99V can last 15 to 20 years or more. Recommended care includes:
Because of its variable operation, the SLP99V experiences less wear and tear compared to single-stage furnaces, which helps extend its life.
Homeowners frequently highlight the SLP99V’s near-silent operation and stable temperatures. Many note lower heating bills and improved comfort compared to older furnaces.
Some drawbacks include higher upfront cost and the need for professional installation by Lennox-certified dealers, which can increase labor rates and availability in some areas.
When researching a premium furnace like the Lennox SLP99V, homeowners often want to know how it compares in cost, efficiency, warranty, and real-world performance. Below are some of the most common questions and answers.
The SLP99V is one of the most efficient furnaces on the market, with an AFUE rating of up to 99%. That means nearly every dollar spent on fuel goes directly toward heating your home, with very little wasted energy.
Installed costs for the SLP99V generally range from $7,000 to $11,000+, depending on your home size, installation complexity, ductwork condition, and regional labor rates. Rebates and incentives may help offset these costs.
Thanks to Lennox’s SilentComfort® technology and insulated cabinet, the SLP99V is exceptionally quiet. Many homeowners describe it as “nearly silent,” even when operating at higher speeds.
The SLP99V includes a lifetime limited warranty on the heat exchanger and a 10-year limited parts warranty when the furnace is registered after installation. Always confirm registration requirements to ensure coverage.
With proper professional installation and regular maintenance, the SLP99V can last 15 to 20 years or more. Its modulating and variable-speed design reduces stress on major components, extending the system’s lifespan compared to single-stage furnaces.
For homeowners in colder climates or those who value quiet operation, smart integrations, and top-tier efficiency, the SLP99V is worth the investment. The fuel savings over time, combined with comfort improvements, help offset the higher purchase price.
The Lennox SLP99V is one of the most efficient and advanced furnaces on the market. With its 99% AFUE rating, ultra-quiet design, and smart integrations, it delivers unmatched comfort and long-term savings.
While it carries a higher price tag, the combination of efficiency, warranty protection, and premium performance makes it a strong investment — especially in cold climates and homes where comfort and quiet matter most.
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