Lennox SLP99V Variable-Capacity Gas Furnace
Best high-efficiency furnace for homeowners seeking quiet, consistent climate control.
Experience unparalleled quiet operation and exceptional energy efficiency with the Lennox SLP99V Variable Capacity Gas Furnace. This high-performance heating solution delivers consistent, even comfort throughout your home thanks to its variable capacity technology and a DC variable speed blower motor. It integrates seamlessly with iComfort Smart Thermostats for advanced control. Recognized as ENERGY STAR Most Efficient 2020, it boasts up to 99% AFUE efficiency. Enjoy peace of mind with a Limited Lifetime Heat Exchanger Warranty, ensuring reliable warmth for years to come.
$8731.00
Owner Satisfaction
4.7
/ 5
Category Rank
1
/ 129
Best Furnaces & Boilers
Price vs Category Average
+219%
Above average
AFUE Efficiency
99
/ %
Who it's for
- Homeowners prioritizing long-term energy savings and lower utility bills
- Residents seeking perfectly consistent temperatures throughout their entire home
- Families desiring a peaceful, quiet living environment
Who should skip it
- Budget-conscious buyers looking for a lower upfront investment
- Owners living in areas without access to certified Lennox technicians
- Shoppers wanting to use existing non-Lennox thermostat or blower equipment
Performance breakdown
Energy Efficiency
Industry-leading AFUE rating minimizes fuel waste and lowers monthly utility bills.
Temperature Consistency
Modulating technology eliminates cold spots for perfectly even home comfort.
Operational Noise
Variable-speed motor ensures whisper-quiet performance during every heating cycle.
Smart Integration
Seamless iComfort connectivity provides intuitive control over your home climate.
Build Reliability
Robust construction backed by an industry-leading lifetime heat exchanger warranty.
Heating Precision
Precise Comfort technology adjusts output in tiny increments for optimal warmth.
Key Specs
AFUE Efficiency
99%
Stage Type
Modulating
Heating System Type
Forced Air
Fuel Type
Natural Gas
Smart Home Compatible
true
Operation
Variable Capacity Operation
Technology
Precise Comfort Technology
Blower Motor
DC Variable Speed Blower Motor
Features
- Quietest and most efficient furnace
- Consistent, even heating
- Precise Comfort Technology
- iComfort Smart Thermostat compatible
- Sealed and insulated blower compartment
- ENERGY STAR certified performance
- Modulating stage type
- Variable capacity operation
What customers say
Users overwhelmingly celebrate the Lennox SLP99V for delivering unparalleled comfort through its precise modulating operation, which maintains exceptionally stable indoor temperatures. A key feature consistently praised is the near silent performance, truly living up to its branding. While the high efficiency promises significant long term energy savings, the initial investment is substantial. The main drawback noted is the premium price point and the complexity of maintenance. Repairs often require specialized technicians familiar with the proprietary control system, leading to potentially costly service calls. Overall satisfaction remains high for those prioritizing ultimate quietness and consistent warmth, viewing the unit as a worthwhile luxury appliance despite the associated service expenses.
Know before you buy
Unlike standard furnaces that only run at full power, a modulating furnace adjusts its heat output in tiny increments. This allows it to maintain a very precise temperature in your home while using only the exact amount of fuel needed, which significantly improves comfort and efficiency.
The SLP99V is specifically designed to integrate with Lennox iComfort smart thermostats. While it offers the best performance and diagnostic features when paired with an iComfort system, you should consult with your installer to see how it fits into your broader smart home ecosystem.
Because the furnace can operate at lower capacities for longer periods rather than constantly cycling on and off at full blast, it consumes significantly less energy. With an AFUE rating of 99%, almost all the fuel consumed is converted into usable heat, leading to lower monthly utility costs.
Yes, it is engineered for near-silent operation. It features a sealed and insulated blower compartment and a DC variable speed motor that runs at lower, quieter speeds most of the time, preventing the loud 'whoosh' sound associated with traditional furnaces.
This model includes a limited lifetime warranty on the heat exchanger, which is the most critical component of the furnace. Additionally, it is eligible for up to 12 years of parts coverage and up to 5 years of labor coverage, depending on the specific registration and installation terms.
The Lennox SLP99V is designed specifically for natural gas. You will need to ensure your home has an existing natural gas line connection to support this unit.
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