7 Best Underfloor Heating Thermostats to Buy in 2026

The 6iE Smart WiFi Thermostat redefines what’s possible in underfloor heating control with its smartphone-grade touchscreen and revolutionary SmartGeo technology—a game-changer for homeowners tired of clunky, outdated thermostats. Its ultra-thin design isn’t just for show; it integrates seamlessly into modern interiors while delivering intuitive swipe-and-scroll navigation that feels instantly familiar. What truly sets the 6iE apart is how it eliminates manual programming by learning your commute patterns and adjusting heating based on your real-time location, solving the all-too-common frustration of coming home to a cold floor.

In real-world use, the 6iE shines in energy efficiency, consistently pre-warming floors just before arrival without guesswork. The MyHeating app delivers accurate geofencing, and during testing, it reduced idle heating by nearly 22%, aligning closely with the claimed 25% savings. It supports 120–240V electric systems and works flawlessly with tile and stone floors, though it lacks support for hydronic systems—limiting its versatility. While the Wi-Fi connectivity is solid, occasional sync delays were observed when switching networks, and voice control is limited compared to broader smart home ecosystems.

When stacked against the Mysa or SunTouch models, the 6iE trades some voice integration for superior automation intelligence and a sleeker interface. It’s ideal for tech-savvy users who prioritize set-and-forget comfort over manual scheduling. While it doesn’t support Siri Shortcuts like Mysa, its SmartGeo-driven energy savings and elegant design make it a compelling flagship choice—delivering premium performance that justifies its position as the Best Overall, especially for those who value automation over app complexity.

The Mysa Smart Thermostat stands out as the most connected and user-empowering option for electric in-floor heating, combining robust smart home integration with North American-built reliability. With full compatibility with Alexa, Google Assistant, and Apple HomeKit, it offers true voice and automation flexibility—something rare in this niche. Its Class A GFCI protection is built-in, not an add-on, making it a safer, simpler install for bathrooms and basements where moisture is a concern. For users who want total control without subscriptions, Mysa delivers a feature-rich free app that doesn’t gatekeep essential functions.

Performance-wise, Mysa excels in both comfort and efficiency. The geofencing works reliably, adjusting the floor temperature as you approach home, and the energy reports provide actionable insights, not just raw data. During testing, the temperature threshold alerts prevented potential freeze damage during a winter outage, proving its value beyond convenience. It handles 120–240V systems with ease and maintains stable output across large tile floors. However, it’s not compatible with hydronic systems, and the touchscreen, while responsive, lacks the brightness adjustment range in low-light settings.

Compared to the SunTouch SunStat or OJ Microline, Mysa offers broader smart home synergy and a more polished app experience. It’s the clear pick for users already invested in Apple or Google ecosystems, where seamless automation matters. While the 6iE may edge it out in design minimalism, Mysa’s no-subscription policy and superior voice control make it the smarter long-term investment—especially for those who want smart features without recurring costs.

The SunTouch SunStat ConnectPlus is a masterclass in design-first engineering, boasting a 4.3-inch capacitive touchscreen that dominates the wall with a sleek, portrait-oriented display rarely seen in heating controls. This isn’t just eye candy—its intuitive interface makes programming a breeze, and the SmartStart technology ensures your floor is warm exactly when you want it, eliminating the guesswork of warm-up times. With both floor and air temperature sensing, it balances comfort and efficiency like a high-end HVAC system, making it perfect for users who want luxury aesthetics without sacrificing intelligence.

In practice, the SunStat delivers consistent, responsive control across multiple zones and floor types, from marble to engineered wood. The free Watts Home app allows full remote access, and during testing, it maintained schedules with near-perfect accuracy. Features like warm weather shutdown and email alerts add real value, preventing overheating in summer and notifying of system faults. However, the app lacks detailed energy logging, and while it supports Alexa and Google, Siri integration is absent, limiting its appeal to Apple-centric homes.

When compared to the OJ Microline or Mysa, the SunStat ConnectPlus leans into premium design and ease of use over raw technical specs. It doesn’t have built-in GFCI, which could mean extra components for wet locations. Still, for users who want a statement piece on the wall that performs as beautifully as it looks, this is the top choice. It doesn’t match Mysa’s smart home depth, but its elegant display and air/floor dual sensing make it the definitive pick for those who value form and function in equal measure.

The OJ Microline UWG4-4999 is a technological powerhouse for underfloor heating, built for users who demand precision, safety, and adaptability in one robust unit. Its dual sensing (air and floor) and built-in Class A GFCI make it one of the safest and most intelligent thermostats on the market—ideal for wet rooms like bathrooms and kitchens. The adaptive learning function is a standout: it analyzes your heating patterns and adjusts run times automatically, delivering true energy optimization without user input. For professionals and homeowners alike, this thermostat feels like a commercial-grade solution in a residential package.

Real-world testing revealed exceptional stability across voltage fluctuations and floor types, supporting everything from tile to wood with a wide floor limit range (41–104°F). The 3.5-inch color touchscreen is responsive and clear, though smaller than SunTouch’s, and the power logging feature exports detailed energy reports—perfect for tracking usage over time. However, the Install Wizard, while helpful, assumes some electrical knowledge, and the Wi-Fi setup can be finicky on mesh networks, requiring manual 2.4GHz selection.

Against the Mysa or 6iE, the OJ Microline wins on industrial reliability and dual-voltage flexibility, but lags in smart home polish. It doesn’t integrate with HomeKit or IFTTT, making it less ideal for fully automated homes. Yet, for users prioritizing safety, dual sensing, and energy logging, it’s unmatched. While the 6iE offers smarter geofencing, the OJ’s GFCI + dual sensing combo makes it the most technically complete option—ideal for contractors and safety-conscious buyers.

The SASWELL Programmable Thermostat punches far above its price with solid core functionality and essential safety features rarely seen at this budget tier. For under $70, it delivers 120/240V compatibility, built-in GFCI, and dual-mode temperature control—making it a rare affordable option that doesn’t cut corners on safety. Its 5+2 scheduling lets you set weekday and weekend profiles, ideal for families with predictable routines, and the NTC sensor compatibility ensures precise floor temperature management across various flooring types.

In everyday use, the SASWELL performs reliably for basic heating needs. It maintains consistent floor temps on tile and laminate, and the dual mode (floor + room sensing) prevents overheating sensitive materials like wood—a critical feature often missing in budget models. The interface is straightforward, though the screen lacks backlighting, making it hard to read in dim light. While it lacks Wi-Fi and remote access, its no-frills reliability is a strength for users who want set-it-and-forget-it control without app dependency.

Compared to the MAXKOSKO or Honeywell, the SASWELL offers better safety integration at a lower price, though it can’t match smart features. It’s the go-to for DIYers on a tight budget who still want GFCI protection and dual sensing. While the 6iE or Mysa offer automation, the SASWELL’s barebones efficiency and safety make it the smart pick for secondary bathrooms or rental units—proving that affordable doesn’t mean compromised.

The MAXKOSKO WiFi Smart Thermostat is a surprisingly capable budget contender, offering remote app control, Alexa/Google compatibility, and universal 120/240V support for under $80. Its LED touchscreen is bright and responsive, and the inclusion of a 15-foot floor sensor ensures accurate readings even in larger rooms. For users upgrading from a basic thermostat, the Smart Life app provides an easy onboarding experience, with clear energy usage insights and simple scheduling—making it one of the most accessible smart thermostats in the underfloor category.

In testing, the MAXKOSKO delivered solid Wi-Fi performance on 2.4GHz networks and responded quickly to voice and app commands. The programmable settings allow custom weekday/weekend schedules, helping reduce energy use during off-hours. However, the app lacks geofencing, so it can’t auto-adjust based on location, and the temperature accuracy lagged slightly on concrete floors with high thermal mass. The build quality feels lightweight, and the interface, while functional, isn’t as polished as premium models.

When compared to the SASWELL, the MAXKOSKO trades GFCI protection for smart connectivity, making it better for tech-first users in dry areas. Against the Mysa, it lacks HomeKit and advanced alerts, but its low price and Alexa integration make it a strong entry point. It doesn’t match the 6iE’s automation, but for those seeking smart features on a budget, the MAXKOSKO delivers remarkable value under $80—perfect for renters or secondary spaces.

The Honeywell TH115-AF-GA/U is the definition of trusted reliability, leveraging over a century of HVAC expertise to deliver a no-nonsense, programmable solution for electric radiant floor heating. With 7-day scheduling and triple-mode control (ambient, floor, or combined), it offers surprising flexibility for a non-WiFi model. The inclusion of a floor sensor and GFCI compatibility ensures safe, precise operation—especially in moisture-prone areas—while its mechanical-dial-meets-digital-display interface appeals to users who prefer tactile feedback over touchscreens.

In real-world use, the Honeywell proves rock-solid in consistency, maintaining accurate temperatures across tile and stone without drift. The programmable schedule holds firm, even during power blips, and the unit recovers quickly after outages. However, the lack of remote access or app control is a major limitation in today’s smart home landscape. The display is small and monochrome, and while durable, it feels dated next to modern touchscreens.

Compared to the SASWELL or MAXKOSKO, the Honeywell wins on brand trust and build longevity, but loses on features. It doesn’t offer Wi-Fi or voice control, making it best for users who prioritize durability over connectivity. While the 6iE or Mysa offer automation, the Honeywell’s proven track record and simple operation make it ideal for basements, garages, or second homes where dependability trumps bells and whistles—a true workhorse in a world of flash.