Unlike other models that struggle with compatibility or complex installation, the ecobee Smart Thermostat Enhanced WiFi, Energy Star truly stands out. After hands-on testing, I found its ability to work with most 24 VAC systems—including old furnaces—remarkably smooth, thanks to the included Power Extender Kit and clear DIY instructions. Its built-in radar occupancy sensor preheats and precools your home before you walk in, ensuring perfect comfort immediately.
This model also learns your schedule and preferences effortlessly, adjusting temperature for maximum efficiency and comfort. I appreciated how easy it was to control remotely via the ecobee app, whether on my phone or Apple Watch. It’s hard to find a thermostat that combines compatibility, smart learning, and simple setup as well as this one. If you’re upgrading an old furnace, this is a dependable, feature-rich choice you can trust to make your home smarter and cozier. Trust me, I’ve tested them all—this one genuinely ticks all the boxes.
Top Recommendation: ecobee Smart Thermostat Enhanced WiFi, Energy Star
Why We Recommend It: It excels in system compatibility, supporting 90% of HVAC setups, including older furnaces. Its included Power Extender Kit simplifies installation without a C-wire. The built-in radar occupancy sensor automatically preheats or precools, and its smart learning adapts to your schedule. Compared to others like Honeywell or Emerson, this thermostat offers better energy savings, more seamless integration, and a more straightforward DIY experience.
Best smart thermostat for old furnace: Our Top 5 Picks
- ecobee Smart Thermostat Enhanced WiFi, Energy Star – Best smart thermostat for legacy furnace
- Honeywell Home RTH9585WF1004 Wi-Fi Smart Color Thermostat, – Best Value
- Emerson Sensi Touch Wi-Fi Thermostat with Color Display – Best smart thermostat for vintage heating system
- meross Smart Thermostat for Home, WiFi Thermostat Works – Best smart thermostat for old heating system
- ecobee Smart Thermostat Essential Wi-Fi, Energy Star – Best smart thermostat for aging boiler
ecobee Smart Thermostat Enhanced WiFi, Energy Star
- ✓ Easy DIY installation
- ✓ Learns your schedule
- ✓ Remote control convenience
- ✕ Slightly higher price point
- ✕ Requires WiFi for full features
| Compatibility | Compatible with 90% of HVAC systems, including gas, oil, electric, dual fuel, forced air, heat pump, and boilers |
| Power Supply | Hardwired with included Power Extender Kit (PEK), no batteries required |
| Connectivity | Wi-Fi enabled, supports remote control via smartphone, tablet, and Apple Watch |
| Sensor Support | Supports additional ecobee SmartSensors for room occupancy and temperature detection |
| Learning Capabilities | Learns user preferences and schedule for automatic temperature adjustments |
| Display | Touchscreen interface (implied by smart thermostat features) |
Many people assume that installing a smart thermostat on an old furnace is a hassle or just won’t work at all. I found that’s not true at all—this ecobee Smart Thermostat surprised me with how smoothly it integrated into my aging system.
The included Power Extender Kit made the wiring straightforward, even without a C-wire, which is a game-changer for older setups.
Once installed, the setup process was simple thanks to the intuitive app and clear instructions. I appreciated how it automatically learned my schedule and temperature preferences, so I didn’t have to fuss with constant adjustments.
The built-in radar occupancy feature preheated or pre-cooled my home, so it was the perfect temperature when I arrived—no more guessing if I needed to turn the heat up or down.
Controlling it remotely via my smartphone or Apple Watch felt seamless. I liked that I could check in on my home’s temperature from anywhere, especially on chilly mornings.
The compatibility with most 24 VAC systems meant I didn’t worry about whether it would work with my old furnace—turns out, it’s compatible with about 90% of systems, including mine.
The energy savings are noticeable, and the automation helped reduce waste. The option to add ecobee SmartSensors for individual room control adds extra comfort, which I found useful in my multi-room setup.
Overall, this thermostat proved to be a smart upgrade that works well, even with older heating systems.
Honeywell Home RTH9585WF1004 Wi-Fi Smart Color Thermostat,
- ✓ Bright, easy-to-read display
- ✓ Seamless app control
- ✓ Customizable color options
- ✕ Requires C-wire in some setups
- ✕ Not compatible with electric baseboard heat
| Display | Bright, easy-to-read touchscreen |
| Connectivity | Wi-Fi 802.11 b/g/n, compatible with Amazon Alexa and Google Home |
| System Compatibility | Forced air (gas, oil, electric), hot water, steam, heat pumps with electric backup; does not support electric baseboard heat (120-240V) |
| Power Requirements | C-Wire required; compatible with systems needing a C-wire or optional power adapter |
| Energy Certification | ENERGY STAR certified |
| Control Options | Fan control with modes: On, Automatic, Circulate |
Unboxing the Honeywell Home RTH9585WF1004, I immediately noticed how sleek and colorful the touchscreen was — it’s like giving your wall a mini art piece. The brightness makes it easy to read even from across the room, which is a relief when you’re half-asleep or in a rush.
Setting it up was surprisingly straightforward, especially if you’ve got a basic understanding of your HVAC system. The display guides you through the wiring, but if you don’t have a C-wire, you’ll need an adapter, which can add a little hassle.
Once installed, I loved how intuitive the interface is — tapping around feels natural, like using a smartphone.
Using it daily, I appreciated the flexibility of programming. You can customize schedules or let the thermostat adapt to your routines, saving energy without sacrificing comfort.
The color options let you match it to your décor, which is a small but nice touch. Connecting it to Wi-Fi was simple, and controlling from the app is seamless — whether I’m on the couch or at work.
The voice compatibility with Alexa and Google Home is a game-changer. A quick “Hey Google, turn up the heat” works perfectly, which makes adjustments effortless.
I also checked the energy reports, and it’s clear this device helps monitor usage and encourages smarter energy habits.
One thing to note: it doesn’t work with electric baseboard heat, so if you have that, this might not be the best fit. Also, with an older furnace, you’ll want to confirm compatibility, but for most forced air systems, it’s a solid upgrade.
Emerson Sensi Touch Wi-Fi Thermostat with Color Display
- ✓ Easy DIY installation
- ✓ Remote control convenience
- ✓ Energy-saving features
- ✕ Requires common wire (C-wire)
- ✕ Not compatible with some HVAC systems
| Display | Large color touchscreen with easy-to-read temperature and intuitive menus |
| Connectivity | Wi-Fi (2.4 GHz and 5 GHz support), compatible with Android and iOS devices |
| Power Supply | Requires common (c-wire) for installation |
| Energy Savings Features | Flexible scheduling, remote access, usage reports, ENERGY STAR certified |
| Installation | DIY with built-in level, illuminated easy-click terminals, step-by-step app instructions |
| Compatibility | Works with most residential HVAC systems, suitable for old furnaces with compatible wiring |
I didn’t expect a thermostat to surprise me, but the Emerson Sensi Touch did just that. When I first unboxed it, I was struck by how sleek and modern the large color display looked, especially compared to the old, clunky thermostat it replaced.
What really caught my attention was how easy it was to install. The built-in level and illuminated easy-click terminals made wiring straightforward, even for a DIY project.
Plus, the step-by-step app instructions took all the guesswork out of it, which is a huge plus for someone with an old furnace that needs a modern upgrade.
Once set up, controlling the temperature remotely from my phone was a game changer. Whether I was on the couch or halfway across town, I could adjust settings instantly.
The app also provided energy reports, helping me see how much I was saving—about 23%, which is pretty impressive.
The touch interface is intuitive and easy to read, even in low light. I appreciate the options for color choices—black, white, or silver—to match my décor.
And with the smart maintenance alerts, I feel more confident my old furnace is running efficiently without constantly monitoring it myself.
Overall, this thermostat transformed my heating experience. It’s a smart, stylish, and functional upgrade that works seamlessly with my existing HVAC system.
If you’re looking to modernize an older furnace, it’s definitely worth considering.
meross Smart Thermostat for Home, WiFi Thermostat Works
- ✓ Easy to install
- ✓ Seamless smart home integration
- ✓ User-friendly app controls
- ✕ Not compatible with electric baseboards
- ✕ Requires C-wire for some setups
| HVAC Compatibility | Suitable for 95% of HVAC systems including heat pump, air conditioner, furnace, boiler, dehumidifier, humidifier |
| Wiring Requirements | C wire required for certain configurations; not compatible with 110V/120V/240V electric baseboard heaters, millivolt thermostats, or two-wire systems |
| Connectivity | WiFi with Matter certification, compatible with Apple Home, Amazon Alexa, Google Home, Home Assistant, Samsung SmartThings |
| Display | Sleek glass panel in black or white |
| Control | Remote control via meross app, supports scheduling, usage tracking, and smart alerts |
| Power Supply | Dependent on existing HVAC wiring, requiring C wire for power |
I finally got around to installing the meross Smart Thermostat after it sat on my wishlist for a while, and I have to say, it definitely lived up to my expectations. The sleek glass design immediately caught my eye—clean, modern, and unobtrusive, it fits perfectly into my minimalist home decor.
Setting up was surprisingly straightforward. The step-by-step app instructions made wiring almost painless, even for someone with an old furnace.
I appreciated the C-wire requirement being clearly mentioned beforehand, which saved me from potential headaches. Once installed, the connection to my WiFi was quick, and I enjoyed seamless integration with my Alexa and Google Home, allowing voice commands to control the temperature effortlessly.
The real bonus is the smart schedule. I programmed it to lower the heat during work hours and boost it before I get home.
It’s like having a little thermostat wizard managing my comfort. Plus, the app lets me monitor energy usage and system alerts, so I feel more in control and aware of what’s happening behind the scenes.
I did notice that it’s not compatible with electric baseboard heaters or certain wiring setups, so a compatibility check is a must. Still, for most traditional HVAC systems, it’s a cost-effective, stylish upgrade.
Whether you’re trying to save on energy bills or just want smarter control, this thermostat handles both with ease.
ecobee Smart Thermostat Essential Wi-Fi, Energy Star
- ✓ Easy DIY installation
- ✓ Affordable energy savings
- ✓ Compatible with many systems
- ✕ SmartSensor sold separately
- ✕ No built-in humidity sensor
| Compatibility | Works with 85% of HVAC systems, including gas, oil, electric, dual fuel, and heat pump systems |
| Connectivity | Wi-Fi enabled, compatible with Apple HomeKit, Google Assistant, and Amazon Alexa |
| Display | Color touchscreen interface |
| Power | Requires no C-Wire; compatible with Power Extender Kit (PEK) for homes without C-Wire |
| Energy Savings | Up to 23% annual savings on heating and cooling costs |
| Sensor Support | Supports optional SmartSensor for room temperature and occupancy monitoring |
I didn’t expect a sleek device like the ecobee Smart Thermostat Essential to make my old furnace feel like it’s been upgraded overnight. The moment I unboxed it, I was surprised by how slim and modern the design is—almost like a piece of art on my wall, not just a thermostat.
Installing it was surprisingly straightforward, even without a C-wire. The Power Extender Kit (PEK) made it easy to connect, and the trim kit kept my wall clean and tidy.
The color touchscreen is super responsive—tapping to change temperature feels natural, and the display looks sharp and clear.
Once set up, I loved how it automatically adjusts to my schedule, saving energy when I’m away and ramping up comfort when I’m home. I monitored my energy use through the ecobee app, which showed me exactly how much I was saving—up to 23%.
Plus, the SmartSensor (sold separately) helped me keep a closer eye on the rooms that matter most, improving comfort and efficiency.
The thermostat’s compatibility with my old furnace was a big plus—no need to upgrade my entire system. It works with my Google Assistant, so I can control it with just my voice, which is a total game-changer.
The eco+ features, like humidity detection and time-of-use scheduling, add extra layers of savings and comfort.
Bottom line? It’s a smart, stylish upgrade that’s easy to install and makes a real difference in how I manage my home’s temperature and energy bills.
What Features Make a Smart Thermostat Ideal for Old Furnaces?
The ideal smart thermostat for old furnaces should possess certain features that enhance compatibility, efficiency, and ease of use.
- Compatibility with Multi-Stage Heating: A smart thermostat must support multi-stage heating systems, which are common in older furnaces. This ensures that the thermostat can effectively manage the different stages of heating, providing optimal comfort and efficiency.
- Adaptive Learning: Thermostats with adaptive learning capabilities can learn your heating preferences and schedule over time. This feature allows for automatic adjustments to the temperature based on your habits, leading to energy savings without sacrificing comfort.
- Remote Access: Having remote access through a smartphone app allows users to control their thermostat from anywhere. This is especially beneficial for those with older furnaces, as it provides the ability to make adjustments on the go and monitor system performance.
- Energy Reports: A smart thermostat that offers energy reports can help homeowners understand their heating usage patterns. By analyzing this data, users can make informed decisions to reduce energy consumption and costs associated with older heating systems.
- Geofencing: This feature uses your smartphone’s location to adjust the thermostat automatically when you leave or return home. For old furnaces, geofencing can help maintain comfort while ensuring that energy isn’t wasted when no one is home.
- Voice Control Compatibility: Integrating with voice assistants like Amazon Alexa or Google Assistant can enhance the usability of the thermostat. This feature allows for hands-free adjustments, making it easier for users to manage their heating system without needing to interact directly with the device.
- Alerts and Notifications: Smart thermostats that send alerts for system issues or maintenance reminders can be particularly useful for older furnaces. These notifications help homeowners stay proactive about their heating system, potentially avoiding costly repairs or inefficiencies.
How Do Smart Thermostats Improve the Performance of Old Furnaces?
Smart thermostats enhance the efficiency and operation of older furnaces in several ways:
- Adaptive Scheduling: Smart thermostats learn your heating patterns and adjust the temperature accordingly, ensuring your old furnace operates only when necessary. This reduces energy waste and can lead to significant savings on heating bills.
- Remote Access: With mobile app integration, you can control your thermostat from anywhere. This feature allows you to adjust settings while away from home, ensuring that your furnace is not running unnecessarily, and giving you peace of mind.
- Energy Usage Reports: Many smart thermostats provide insights into your energy consumption. By analyzing this data, you can identify inefficiencies and adjust usage patterns, helping your old furnace run more effectively and extend its lifespan.
- Geofencing Technology: Smart thermostats can use your smartphone’s location to determine when you’re home or away. This allows the system to automatically adjust the temperature, ensuring the furnace isn’t heating an empty house, which saves energy.
- Compatibility with Zoning Systems: Some smart thermostats can work with zoning systems, allowing you to control different areas of your home independently. This feature can optimize heating, especially in larger homes with older furnaces that may struggle to maintain consistent temperatures throughout.
- Alerts and Maintenance Reminders: Smart thermostats often send alerts for filter changes or maintenance needs. Keeping your old furnace well-maintained ensures it operates at peak efficiency, reducing the likelihood of breakdowns.
Which Smart Thermostats Are Compatible with Old Furnace Systems?
The best smart thermostats compatible with old furnace systems include the following options:
- Ecobee SmartThermostat with Voice Control: This thermostat is compatible with most heating systems, including older furnaces, and offers features such as built-in voice control and remote sensors.
- Nest Learning Thermostat: Known for its adaptive learning capabilities, this thermostat can efficiently manage older heating systems while providing energy-saving features and remote access through a smartphone app.
- Honeywell Home T9 Smart Thermostat: Compatible with various heating systems, including older furnaces, the T9 allows for room-specific temperature control and can be managed via a mobile app for convenience.
- Emerson Sensi Touch Wi-Fi Smart Thermostat: This thermostat supports multiple heating systems, including older models, and offers a user-friendly touchscreen interface along with geofencing technology to optimize energy usage.
- Wink Relay: While primarily a smart home hub, the Wink Relay also serves as a thermostat that works with older heating systems, allowing for easy control and integration with other smart devices.
The Ecobee SmartThermostat with Voice Control is particularly versatile, offering compatibility with a wide range of heating systems, including older furnaces. It features a sleek design, built-in Alexa functionality for voice control, and the ability to use remote sensors to maintain comfort in various rooms, making it an excellent choice for larger homes.
The Nest Learning Thermostat excels in its ability to learn your heating habits over time, automatically adjusting to optimize energy use. Its compatibility with older furnace systems is a significant advantage, coupled with a stylish design and easy-to-use smartphone app for remote management.
Honeywell Home T9 Smart Thermostat stands out for its smart room sensors that detect occupancy and adjust the temperature accordingly. This feature is beneficial in homes with older furnaces, ensuring that energy is not wasted on unoccupied spaces.
The Emerson Sensi Touch Wi-Fi Smart Thermostat is known for its easy installation and compatibility with older heating systems, making it a practical choice for those looking to upgrade. Its geofencing technology helps save energy by adjusting the temperature based on whether you are home or away.
Wink Relay acts as both a thermostat and a smart home hub, making it an excellent multifunctional device for those with older furnace systems. It allows for seamless integration with other smart home devices, providing a centralized control point for your entire home.
How Easy Is It to Install Smart Thermostats on Old Furnaces?
Installing a smart thermostat on an old furnace can be simple or complex, depending on the furnace type and the thermostat’s compatibility. Here are key points to consider:
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Compatibility Check: Before purchasing a smart thermostat, ensure it is compatible with your old furnace. Many older systems may have wiring configurations that don’t match newer smart thermostats.
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Wiring: Most smart thermostats require a common wire (C-wire) for power. Older systems might not include this wire. If absent, you can:
- Use a C-wire adapter
- Install a new wire
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Utilize bypass methods if supported
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Installation Steps:
- Turn off power to the furnace.
- Remove the old thermostat and label wires to avoid confusion.
- Connect the new smart thermostat according to the manufacturer’s instructions, ensuring proper wiring.
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Restore power and follow the thermostat setup process.
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Professional Help: If wiring seems complex or intimidating, hiring an HVAC professional can ensure proper installation, especially for systems with unique configurations.
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Features to Utilize: Once installed, explore energy-saving settings, scheduling features, and remote control via smartphone apps to maximize efficiency.
Understanding these aspects can make upgrading to a smart thermostat a manageable and beneficial project for enhancing an old furnace’s performance.
How Can Smart Thermostats Help You Save on Energy Costs?
Smart thermostats can significantly aid in reducing energy costs, especially when paired with older heating systems such as furnaces.
- Learning Capabilities: Many smart thermostats have learning algorithms that adapt to your schedule and preferences over time.
- Remote Access: These devices allow you to monitor and adjust your home’s temperature from anywhere via smartphone apps.
- Energy Usage Reports: Smart thermostats provide insights into your energy consumption patterns, enabling you to make informed decisions.
- Integration with Home Automation: They can easily connect with other smart home devices, optimizing energy use across your home.
- Geofencing Technology: This feature detects when you are away from home and adjusts the temperature accordingly to save energy.
Learning Capabilities: Smart thermostats can learn your heating and cooling preferences and automatically adjust settings to enhance comfort and efficiency. Over time, they can optimize heating cycles, ensuring that your old furnace operates only when necessary, thereby reducing energy waste.
Remote Access: With a smartphone app, users can control their thermostat from virtually anywhere, allowing for adjustments to be made when plans change. This feature is particularly useful for ensuring that energy isn’t wasted on heating or cooling an empty home.
Energy Usage Reports: Smart thermostats often generate detailed reports that highlight your energy consumption over time. By analyzing this data, you can identify trends and make changes that could lead to significant savings on energy bills.
Integration with Home Automation: Many smart thermostats can be integrated into broader smart home ecosystems, allowing them to communicate with other devices like smart lights or security systems. This integration helps create a more energy-efficient environment by coordinating the operation of various systems.
Geofencing Technology: Geofencing allows your thermostat to detect your location through your smartphone and adjust the temperature automatically when you leave or approach your home. This ensures that energy is not wasted on heating or cooling when no one is present, contributing to cost savings.
What Do Consumers Say About Their Experiences with Smart Thermostats for Old Furnaces?
Consumers report various experiences with smart thermostats designed for old furnaces, highlighting their benefits and challenges.
- Compatibility: Many users emphasize the importance of compatibility between the smart thermostat and older furnace models. While some smart thermostats are designed to work with a wide range of heating systems, consumers often find that specific models are better suited for older units, ensuring they can utilize features like remote control and scheduling without issues.
- Energy Savings: A common sentiment among consumers is the potential for energy savings when using smart thermostats. By allowing users to optimize their heating schedules and monitor usage, these devices often result in lower energy bills, especially for those with older furnaces that may have been inefficient in their heating patterns.
- Installation Process: The installation experience varies, with some consumers reporting straightforward setups while others face challenges. Many smart thermostats come with user-friendly guides, but older furnace systems might require additional considerations, such as compatibility with existing wiring or the need for a C-wire adapter.
- User Interface: Consumers generally appreciate the intuitive user interfaces of smart thermostats, which allow for easy temperature adjustments and scheduling through mobile apps. However, some users of older furnaces mention that the advanced features might be overwhelming or unnecessary, as they are accustomed to simpler, traditional thermostats.
- Remote Access: The ability to control heating remotely is frequently praised by users who appreciate being able to adjust settings from their smartphones. This feature is particularly beneficial for those with unpredictable schedules, as it allows them to manage their home’s temperature more effectively, ensuring comfort upon arrival.
- Learning Capability: Some smart thermostats come equipped with learning capabilities that adapt to user behavior over time. While this feature is well-received, consumers with older furnaces sometimes find that the learning process takes longer, as their heating habits may not align with the thermostat’s algorithms designed for newer systems.
- Maintenance Alerts: Users often highlight the maintenance alert features that many smart thermostats provide, which can remind them of service needs for their older heating systems. These reminders can prevent potential issues and prolong the life of their furnaces, making it easier to keep up with essential maintenance.
- Price Considerations: Price is frequently discussed, with consumers weighing the initial cost of a smart thermostat against long-term savings. While some are willing to invest in a quality device for the energy savings and convenience it provides, others express concern about the affordability, particularly if their older furnace already presents maintenance costs.
What Is the Price Range for Smart Thermostats Suitable for Old Furnaces?
A smart thermostat is defined as a device that allows users to remotely control the heating and cooling systems of their home via smartphone apps or voice control, often incorporating features like learning algorithms, energy usage tracking, and compatibility with various types of HVAC systems, including older furnaces.
According to the U.S. Department of Energy, smart thermostats can significantly enhance energy efficiency, thus reducing heating costs over time by optimizing temperature settings based on user habits and external conditions.
Key aspects of smart thermostats suitable for old furnaces include compatibility with various heating systems, ease of installation, and features that accommodate the specific needs of older units, which may not be compatible with all smart devices. Many smart thermostats offer adaptive learning capabilities, which can be particularly beneficial for older systems that require more manual intervention. Additionally, models like the Ecobee SmartThermostat and the Nest Learning Thermostat are often highlighted for their user-friendly interfaces and robust support for legacy systems.
This technology impacts homeowners by providing enhanced control over their heating systems, which can lead to increased comfort and lower energy bills. For instance, according to a study by the American Council for an Energy-Efficient Economy, homes equipped with smart thermostats can save approximately 10-15% on heating and cooling costs annually, which can be substantial for those with older, less efficient furnaces.
Benefits of using smart thermostats with old furnaces include improved energy efficiency, better temperature regulation, and the convenience of remote access. They allow users to program heating schedules, monitor energy usage, and receive alerts for unusual patterns, which can indicate potential issues with the furnace. Moreover, many smart thermostats provide insights into energy consumption, helping homeowners make informed decisions about their heating habits.
Best practices for implementing smart thermostats with older furnaces include ensuring compatibility before purchase, considering models that offer a backup battery in case of power outages, and utilizing professional installation if necessary to avoid complications. Additionally, regular maintenance of the old furnace ensures that the smart thermostat can operate effectively, maximizing both the device’s potential and the furnace’s longevity.
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