Dave Lennox Signature Collection SLP99V Review

The SLP99V is the top-of-the-line Lennox furnace and the most efficient furnace on the market. Consequently, it’s also one of the most expensive. This variable-capacity gas furnace is perfect for homeowners with a very healthy budget who want a heating system that will provide maximum efficiency and energy savings.

When you're in the market for a new Lennox furnace, read this review first. It will help you decide if the SLP99V is the right natural gas furnace for your upgrade.  

We’ll talk about its design features, efficiency rating, price range, warranty details, and special features. Plus, we’ll compare the SLP99V to three other Lennox furnace models to show you what kind of furnace you can get at a different price range or with other features.

The Dave Lennox Signature Collection SLP99V in a Nutshell

Average Price (with installation): $7,200 to $7,800

Top Features

The Bottom Line

• ENERGY STAR® Most Efficient 2021
• One of the quietest heating systems available
• Excellent humidity control
• Reduced greenhouse gas emissions
• Most efficient furnace available
• Has a secondary heat exchanger
• Condensing technology reduces heat and fuel waste
• Standard warranty coverage
• Has Lennox’s SilentComfort™ technology
• Compatible with humidifiers and air filters
• Precise Comfort® technology keeps the temperature exactly where you want it
• Powered by the Duralok Plus™ heat exchanger
• Part of the Ultimate Comfort System™

The Bottom Line

Looking to reduce energy costs? When you need a new furnace, want the most efficient heating system, and have a large budget, this Lennox model might fit the bill.

It has an efficiency rating of 99 percent, so it’s the most efficient furnace on the market, converting $0.99 of every dollar you spend into heat for your home.

This is a modulating, variable-speed furnace, so it can adjust the heating output and airflow in 1-percent increments to provide extremely quiet, even heat.

Not only does it virtually eliminate hot and cold spots throughout the house, but it’s also capable of keeping any home warm—no matter how large your house or how low the mercury drops. Plus, it’s equipped with all of Lennox’s standard and premium features.

 

In Depth Review

Dave Lennox Signature Collection SLP99V Product Specifications

• AFUE: 99 percent
• Burner type: Modulating
• Blower type: Variable-speed
• ENERGY STAR certified: Yes

Features Overview

The SLP99V is compatible with Lennox’s Ultimate Comfort System, a collection of technologies—including Lennox’s proprietary smart thermostat and the PureAir filter—that can improve performance, efficiency, and air quality. 

This model is also compatible with the iComfort® S30 smart thermostat, which provides advanced diagnostics and troubleshooting, automatic temperature adjustments, and automatic adjustments to the operation based on outdoor air quality and pollen levels. 

Plus, Lennox’s smart thermostat has a geofencing feature that enables you to connect a mobile device so that the system will automatically turn on or shut off when you come home or leave the house. It can even send messages to your HVAC dealer when issues arise. 

Another great thing about the SLP99V is that it’s equipped with Lennox’s Duralok Plus™ heat exchanger, which has a special clamshell design and is made with ArmorTuf™ steel to guarantee efficiency, reliability, and long life. 

Finally, this Lennox furnace has SilentComfort technology, which includes the variable-speed blower motor and quiet starts and stops. Lennox advertises this as the quietest furnace available.

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Other Key Features

• Has an insulated cabinet blower compartment, reducing heat loss and noise
• Dual fuel compatible, meaning the furnace can be paired with an electric heat pump to use the most economical fuel at any given time
• Patented burner box that improves efficiency and reduces emissions
• Can be integrated with the PureAir filter for improved indoor air quality
• Has an ultra-low continuous fan
• Equipped with a fuel-saving SureLight® silicon nitride ignitor

Warranty Information

The SLP99V comes with a lifetime heat exchanger warranty and a 10-year parts warranty. To qualify for the full warranty, you must register the furnace within 60 days of installation, otherwise you risk losing some of the coverage.

You should also have the furnace installed by a licensed HVAC professional to avoid invalidating the warranty. Be sure to budget for installation costs as well as the purchase price!

Lennox furnace prices are higher than most, especially for a top model like the SLP99V, but their warranty protection isn't as good as a lot of other less expensive brands.

For example, a lot of other HVAC manufacturers have started offering unit replacement warranties on top of their heat exchanger warranties, but Lennox hasn’t jumped on board with that type of coverage.

Comparable Lennox Furnace Models

Model Comparison by Price: SLP99V versus Merit ML193E

The Merit ML193E is an entry-level furnace in the Merit series, so it’s the most affordable high-efficiency furnace that Lennox makes, costing about $4,000 to $4,500 to buy and install. 

There are, however, some sacrifices you'd have to make for the lower price. For one, the ML193E only has single-stage operation with a constant torque blower, and these furnaces aren't as quiet, efficient, or as capable of keeping larger homes warm. 

This model also has an AFUE of 93 percent, and it’s not ENERGY STAR certified. That means it probably won’t qualify for a lot of rebates that the SLP99V is eligible for, and you won’t see the same savings on your heating bills compared to the SLP99V. 

Single-stage furnaces work better in milder climates and smaller homes because they don’t produce the same level of consistent heat. Further, the Canadian government recently increased the AFUE minimum to 95 percent for high-efficiency furnaces, so this model may not be available here.

Model Comparison by Features: SLP99V versus Elite EL196E

The EL196E is one of the Lennox Elite series furnaces. It lacks a number of design features that the SLP99V boasts because it’s a single-stage furnace with a constant torque blower and an AFUE of 96 percent. 

In other words, it won’t save you as much on energy costs, it won’t be as quiet, and it might not be powerful enough for the coldest parts of Canada. 

However, there is one thing the EL196E offers, and that is compatibility with Amazon Alexa and Apple HomeKit, both of which can give you voice control access to the system when it’s paired with a smart thermostat.

Model Comparison by Tier: SLP99V versus SL297NV

The SL297NV is another furnace in the Dave Lennox Signature Collection series, and it’s the closest to the SLP99V in terms of features, price, and specifications. It’s also compatible with the same Lennox technologies, the iComfort® S30 smart thermostat and the PureAir filter. 

However, the SL297NV is only a two-stage gas furnace, meaning it can change between a high and low heat output, but it can’t make incremental adjustments to it. It does, however, have a variable-speed blower, so it can incrementally change the airflow.

Furthermore, the SL297NV has a lower 97.5 AFUE, so it won’t save you quite as much on energy bills, though the difference in energy costs won’t be very noticeable. 

On the other hand, the SL297NV does boast ultra-low nitrogen oxide emissions, and it was also awarded the ENERGY STAR Most Efficient 2021 certification.