21J71

Introducing the Lennox Model 21J71 Box Heat Pump Thermostat, a state-of-the-art HVAC control solution designed to ensure optimal comfort and energy efficiency in your home. This user-friendly thermostat is engineered to work seamlessly with Lennox heating and cooling systems, providing precise temperature control, enhanced features, and intuitive operation.

The 21J71 thermostat boasts a sleek, modern design that complements any decor. Its large, backlit display ensures easy reading of temperature settings and other vital information, even in low-light conditions. The unit features a simple, one-button access to the menu, allowing you to customize settings with ease.

This advanced thermostat is equipped with an intelligent, adaptive recovery feature, which learns your temperature preferences and adjusts the system accordingly. This not only ensures a consistent indoor environment but also helps to optimize energy usage, reducing heating and cooling costs.

The Model 21J71 thermostat supports multiple scheduling options, including 7-day and 5-2-1 programming. This level of customization enables you to create a personalized heating and cooling schedule that suits your lifestyle and energy savings goals.

Additionally, the 21J71 thermostat is Wi-Fi enabled, allowing you to remotely access and control your system using the iComfort app. This feature offers the convenience of adjusting temperatures, monitoring energy usage, and receiving maintenance alerts from anywhere, at any time.

The Lennox Model 21J71 Box Heat Pump Thermostat is designed with ease of installation in mind. It features a universal mounting plate and clear installation instructions, making it simple for homeowners and professionals to install. The thermostat is also compatible with most HVAC systems, including gas, oil, electric, and heat pump systems.

With its advanced features, user-friendly design, and energy-saving capabilities, the Lennox Model 21J71 Box Heat Pump Thermostat is the perfect addition to any modern HVAC system, ensuring unparalleled comfort and convenience while reducing energy consumption and costs.

Lennox 21J71 Box Heat Pump Thermostat: A Comprehensive Analysis

The Lennox 21J71 is a popular box heat pump thermostat that offers several features to enhance comfort and energy efficiency. In this analysis, we will discuss the pros and cons of buying this thermostat to help you make an informed decision.

1. Seven-Day Programmability: The Lennox 21J71 allows users to set heating and cooling schedules for up to seven days. This feature can save energy by adjusting the temperature when you're away or sleeping.

2. Energy Savings: The thermostat offers energy-saving features, such as the Smart Recovery and Vacation modes, which can help reduce energy consumption and lower utility bills.

3. Compatibility: The Lennox 21J71 is compatible with various HVAC systems, including gas and oil furnaces, heat pumps, and air conditioners.

4. User-Friendly: The thermostat has a large, easy-to-read display and intuitive interface, making it simple for users to program and adjust settings.

5. Remote Access: With the iComfort S30 Smart Thermostat, users can remotely access and control their Lennox 21J71 thermostat using a smartphone, tablet, or computer.

1. Cost: The Lennox 21J71 is more expensive than some basic thermostats on the market. However, its advanced features and compatibility with various HVAC systems may justify the investment.

2. Installation: Installing the thermostat may require professional assistance, which can add to the overall cost.

3. Integration with Other Devices: Although the Lennox 21J71 can be integrated with other smart home devices, such as Amazon Alexa and Google Home, users may need additional components or subscriptions to enable these features.

The Lennox 21J71 box heat pump thermostat offers several advanced features designed to enhance comfort, energy efficiency, and convenience. While its cost and installation may be drawbacks for some, its compatibility with various HVAC systems, user-friendly interface, and remote access capabilities make it a worthwhile investment for homeowners seeking a high-performing, connected thermostat solution.

If you're looking for a versatile, feature-rich thermostat that can be integrated with your existing HVAC system and offer energy savings and remote access, the Lennox 21J71 box heat pump thermostat is an excellent choice. However, if you're on a tight budget or prefer a simpler thermostat, you may want to consider alternative options with more basic features.

Details:

There is some wear/scuff but no major damage. This item is new in box and overall great condition. The outer box does have wear dust and some defacing but the thermostat itself is in great condition.

specifications maxohvac:

• brand: Lennox
• mpn: 21j71
• part type: Box Pump Thermostat

payments maxohvac:

• other
• wallet: apple-pay
• credit card: discover

seller maxohvac:

• # reviews: 14374
• rating: 99.9%
• city: canton, georgia

general maxohvac:

• category: Business & Industrial > Hvac Refrigeration

shipping maxohvac:

• service: usps ground advantage
• class: standard
• type: fixed
• carrier: usps
• transit: 5-9 days

returns maxohvac:

• policy: returns accepted
• method: money back
• paid by: buyer
• time: 30 days

offer maxohvac:

• sold #: 9
• in stock #: 3
• started: december 25, 2025
• prices: $47.48–$389.00
• item condition:
  • New
  • Used
• best offers: true
• options: ship-to-home
• availability: in stock

Also Viewed:

• 17W11: THERMOSTAT, Lennox
• 59M03-18J20-18J2001: TRAP, Lennox
• 71W49-71W4901-102907-01: SWITCH, Lennox
• EBJ61970007: , Lennox
• R8330J-1001-87163-P-8-10414: , Lennox Ducane Armstrong Allied Honeywell
• 81W20: CAPACITOR, Lennox
• 45C02: KIT, Lennox Klixon
• BE25586002: TRANSFORMER, Lennox Ducane Armstrong Basler Products Unlimited
• 86H3101: PRESS SWITCH BOX, Lennox
• 16Y42: KIT, Lennox
• 5SME39NXL3053: BLOWER MOTOR CONTROLLER, Lennox Ducane Armstrong Ge Genteq