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What Is the Best Honeywell Evohome for Underfloor Heating Control in 2026?

Quick Answer: The Honeywell TH115-AF-GA/U Radiant Heating Programmable Thermostat stands out as the top choice for dedicated underfloor heating control in 2026, offering three temperature control modes (ambient, floor, or ambient with floor limits), a built-in floor sensor, GFCI protection, and 7-day programmability in a single unit. For budget-conscious homeowners, the generic Programmable Thermostat for House Radiant Underfloor Heating (ASIN: B08QJS8MV8) delivers similar dual-sensor functionality and GFCI safety at under $100. Most Honeywell underfloor heating thermostats range from $25 to $218, depending on features and programmability. The key takeaway: investing in a thermostat with dedicated floor sensing and GFCI protection prevents temperature swings and electrical hazards in radiant floor systems.

Honeywell Evohome systems represent a family of heating control solutions designed specifically for modern home comfort. Underfloor heating—also called radiant floor heating—has grown significantly in popularity since 2024, with homeowners appreciating the even heat distribution and energy efficiency compared to traditional forced-air systems. Controlling underfloor heating requires specialized thermostats that monitor both ambient room temperature and floor surface temperature simultaneously. Standard wall thermostats cannot safely manage the high electrical loads or temperature nuances of radiant systems. Honeywell’s range of underfloor-specific controls, from basic programmable models to advanced smart options, addresses this gap. This article reviews six Honeywell products spanning budget, mid-range, and premium categories to help you select the right control system for your radiant floor installation.

Which Honeywell Underfloor Heating Thermostats Stand Out in 2026?

Honeywell TH115-AF-GA/U Radiant Heating Programmable Thermostat with Floor Sensor and GFCI

The TH115-AF-GA/U is purpose-built for radiant floor heating systems and represents Honeywell’s flagship offering for this application. This 120/240V programmable thermostat features three distinct temperature control modes: ambient-only, floor-only, or a hybrid mode that maintains ambient comfort while setting maximum floor temperature limits. The integrated floor sensor allows real-time monitoring of surface temperature, preventing overheating and extending the lifespan of floor materials. A built-in GFCI (Ground Fault Circuit Interrupter) protects against electrical leakage, meeting safety standards outlined by NFPA electrical codes. The 7-day programmable schedule supports four daily periods (wake, leave, arrive, sleep), enabling energy-efficient operation tailored to your household rhythm.

Who It’s Best For: Homeowners with existing radiant floor heating systems seeking reliable, dedicated control without smart home integration. Ideal for those prioritizing safety (GFCI) and temperature precision over app-based management.

Pros: Three control modes offer flexibility; integrated floor sensor prevents overheating; GFCI protection built-in; 7-day programming reduces energy waste; compatible with 120V and 240V systems; made to withstand radiant heating loads.

Cons: No smart home connectivity or remote access; no app control; requires manual programming; limited learning capabilities compared to modern smart thermostats.

Honeywell TH115-AF-GA Radiant Floor Heating Thermostat 120/240V

Honeywell TH115-AF-GA Radiant Floor Heating Thermostat 120/240V

Programmable
Honeywell
amazon.com
In Stock
$217.95
Updated: 1 month ago
Price as of April 24, 2026 2:31 pm. We earn from qualifying purchases.
  • Brand: Honeywell
  • Product number: TH115-AF-GA
  • 7-day programmable line volt thermostat for elect
  • Category: HVAC. Three choices of temperature control in a single thermostat (Ambient, Floor, or Ambient with Floor temperature limits). Application-Radiant floor

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Programmable Thermostat for House Radiant Underfloor Heating with Dual Sensing and GFCI (ASIN: B08QJS8MV8)

This versatile underfloor heating controller operates on both 120V and 240V circuits with a maximum capacity of 3600W at 240V, making it suitable for larger radiant floor zones. The dual-sensor design monitors both air temperature and floor surface temperature simultaneously, with the thermostat intelligently selecting which reading controls heating output. The built-in Class A GFCI protection includes a manual test function and automatic shutoff if leakage exceeds 5mA, aligning with Canadian Standards Association (CSA) requirements for GFCI devices. A large LCD display with backlight shows temperature and programming status clearly, and the 7-day schedule allows separate weekday and weekend programs with four daily periods.

Who It’s Best For: Budget-conscious homeowners installing or upgrading radiant floor heating in medium-to-large areas. Those who need dual-voltage flexibility and prioritize safety features without premium pricing.

Pros: Dual sensing (air and floor) with self-adaptive logic; supports 120V and 240V; high power capacity (3600W at 240V); built-in GFCI with test function; 7-day programmable; large backlit LCD; 5-year limited warranty; universal compatibility.

Cons: No smart home integration; manual programming only; no remote access; less brand recognition than Honeywell’s heritage models; requires understanding of GFCI troubleshooting if leakage occurs.

BOWSEN Programmable Radiant Floor Heating Thermostat 120/240V

BOWSEN Programmable Radiant Floor Heating Thermostat 120/240V

Programmable
BOWSEN
amazon.com
In Stock
$96.99
Updated: 1 month ago
Price as of April 24, 2026 2:31 pm. We earn from qualifying purchases.
  • This Underfloor Radiant Heating thermostat works with both 120VAC / 240VAC, 50/60Hz. The maximum current for either voltage is 15A. Maximum Power Wattage: 120V/ 1800W or 240V/ 3600W, Comply with the requirements of the Standard(s) for Ground Fault Circuit Interrupters (CAN/CSA-C22.2 No. 144.1) and are identified with the cETL Listed Mark.
  • With Floor and Air Sensor, build in GFCI and GFCI function test. There is a Ground Fault Circuit Interrupter GFCI inside the thermostat. It is used to protect occupants from electric shock if there is a short circuit, After installing the thermostat, test this function to ensure proper and safe operation. It can also prevent some electrical fires and reduce the severity of others interrupting the flow of current.
  • If the GFCI is tripping, it means that there is an electricity leakage detected. Please shut down your main power and re-connect the wires. Make sure there is no electricity leakage up to 5mA, or the thermostat will alarm for safety. and check your floor cable for short circuit or leakage! Then check and switch the GFCI toggle on the side of the thermostat. If it is not working, please go to the hidden menu and turn off the GFCI alert.
  • Large LCD digital display with backlight,easy to read in various lighting conditions, 7-day programmable line volt thermostat for elect. 7 day program scheduling helps to provide maximum comfort, while reducing operating costs.ON/STANDBY switch enables thermostat shutdown at end of heating season.
  • Universal compatibility with existing radiant floor heating systems.The thermostat is UL listed, with self-testing Class A GFCI (Ground Fault Circuit Interrupter) to protect against risks of electrocution caused by current leakage. Load capacity of 15amps. 5 year limited warranty.
  • When the thermostat is under working, please kindly set the target temperature to be higher than the current room temperature so that the heating will be on. Then please push the button on the side to test the GFCI function. This GFCI function can only be triggered with the thermostat's relay is working on. Any further question, please ask me freely.

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Honeywell Home RLV4305A1000 5-2 Day Programmable Thermostat for Electric Baseboard Heaters

While marketed for electric baseboard heaters, the RLV4305A1000 offers features applicable to certain radiant heating setups, particularly electric resistance-based systems. This digital 5-2 day programmable thermostat delivers exceptional temperature accuracy of ±0.27°F, among the most precise on the market according to Honeywell’s specifications. TRIAC switching technology enables 100% silent operation and eliminates temperature swings common in less sophisticated controllers. The 5-2 programming structure allows separate weekday and weekend schedules with four daily periods. Two-wire non-polarized connections simplify installation, and the compact design fits standard wall switch boxes.

Who It’s Best For: Homeowners with electric resistance radiant heating systems who prioritize temperature stability and silent operation. Best suited for retrofits where installation simplicity matters and existing wiring is already in place.

Pros: Exceptional temperature accuracy (±0.27°F); TRIAC switching eliminates noise and temperature swings; 5-2 day programming; simple 2-wire installation; compact design; proven reliability; affordable entry point.

Cons: Not specifically designed for radiant floors with floor sensors; no GFCI protection; no smart features; limited to electric resistance heating; no ambient temperature display on some versions; 5-2 programming less flexible than 7-day options.

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Honeywell RLV4305A1000 5-2 Day Programmable Electric Baseboard Thermostat

Honeywell RLV4305A1000 5-2 Day Programmable Electric Baseboard Thermostat

Programmable
Honeywell Home
amazon.com
In Stock
$54.98 $60.99 Save $6.01
Updated: 1 month ago
Price as of April 24, 2026 2:31 pm. We earn from qualifying purchases.
  • Digital 5-2 Day Programmable Thermostat for electric baseboards, convectors and fan-forced heaters.
  • The most accurate type of thermostat on the market (accuracy of ± 0.27 degreeF with baseboards and convectors).
  • TRIAC switching allows for 100 percent silent operation and unsurpassed temperature control that helps eliminate temperature swings.
  • 5-2 Day Programming allows for separate programs for the weekdays and weekends with 4 program periods per day including wake, leave, arrive and sleep.
  • 2-wire non-polarized connection means fast, hassle-free installation.
  • Backlit display for easy reading and instructions inside front panel enable quick, easy programming.
  • Temporary bypass enables temperature override without changing programming.
  • Line volt heating only (240V) including electric baseboards, convectors and fan-forced heaters. Also ideal for radiant ceilings.
  • Power maximum load: 3,500W @ 240V, 14.6 A resistive; Minimum load: 2 A resistive.
  • This thermostat is designed to control an electric heating system such as a baseboard heater, a radiant ceiling, a convector or a fan-forced heater. The thermostat CAN NOT be used with: a resistive load under 0.83, a resistive load over 14.6, a system driven by a contactor or a relay (inductive load), and a central heating system.

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Honeywell TH1100DV1000/U Pro 1000 Vertical Non-Programmable Thermostat

The Pro 1000 represents Honeywell’s basic, non-programmable thermostat line. This vertical-mount model offers simple on/off heating control without scheduling features, making it suitable only for supplemental heating zones or temporary installations. The compact 4.7-inch height and 2.9-inch width fit standard wall spaces. A manual setpoint dial allows users to select desired temperature, with the thermostat maintaining that temperature until manually adjusted. This model lacks digital displays, floor sensing, GFCI protection, and programmability—features essential for modern radiant floor heating systems.

Who It’s Best For: Not recommended for primary underfloor heating control. May serve as a backup or emergency heating control in non-critical spaces, or for users with extremely simple heating needs who reject digital interfaces.

Pros: Simple, reliable mechanical operation; extremely affordable; compact footprint; made in the United States; minimal failure points due to simplicity.

Cons: No programmability; no floor sensor; no GFCI protection; no digital display; manual adjustment only; unsuitable for radiant floor heating; no temperature memory; lacks modern safety features.

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Honeywell TH1100DV1000 Non-Programmable Thermostat

Honeywell TH1100DV1000 Non-Programmable Thermostat

Programmable
Honeywell
amazon.com
In Stock
$35.99 $45.00 Save $9.01
Updated: 1 month ago
Price as of April 24, 2026 2:31 pm. We earn from qualifying purchases.
  • 4 11/16 in. High x 2 7/8 in. Wide x 1 1/8 in. Deep
  • Premier white color
  • Made in United States
  • Package Dimensions : 12.0 L x 6.0 H x 12.0 W (inches)

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Honeywell Home RTH111B Digital Non-Programmable Thermostat

The RTH111B steps up from the Pro 1000 by adding a digital display and soft-touch controls, but remains non-programmable. This model provides precise temperature control within ±0.5°C (±0.9°F) and features an easy-to-read digital display showing current temperature setpoint. Soft-touch buttons replace mechanical dials, improving user experience and reducing accidental adjustments. A battery compartment with low-battery reminder notification ensures the thermostat remains powered during electrical outages. Set point memory preserves your temperature preference if power is temporarily lost, eliminating the need to reprogram after outages.

Who It’s Best For: Homeowners seeking basic digital control without programmable scheduling. Suitable for supplemental heating zones or rental properties where tenants should not access scheduling features.

Pros: Digital display improves readability; soft-touch buttons prevent accidental changes; reasonable temperature accuracy (±0.5°C); battery backup with low-battery alert; set point memory; affordable; reliable Honeywell brand.

Cons: Non-programmable; no floor sensor; no GFCI protection; no smart features; not designed for radiant floor heating; manual operation only; cannot optimize energy use through scheduling.

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Honeywell RTH111B Non-Programmable Digital Thermostat

Honeywell RTH111B Non-Programmable Digital Thermostat

Programmable
Honeywell Home
amazon.com
In Stock
$25.25 $31.65 Save $6.40
Updated: 1 month ago
Price as of April 24, 2026 2:31 pm. We earn from qualifying purchases.
  • PRECISE TEMPERATURE CONTROL: Precise temperature control of +/- 0.5 degree Celsius.
  • DIGITAL DISPLAY: Easy-to-read digital display.
  • SIMPLE TO USE: Simple, soft-touch buttons allow you to select the temperature quickly and easily.
  • EASY-ACCESS: Easy-access battery compartment and change battery reminder.
  • SET POINT RETAINED: Set point is retained in memory in the event of a power outage.
  • COMPATIBLE WITH: Heating, cooling and heat pumps without auxiliary heat options.
  • NOT Compatible with: Does NOT work with electric baseboard heat (120-240 V), heat pumps with backup, or multi-stage heating/cooling.

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Honeywell Genius HeatGenius Ceramic Heater with Programmable Thermostat

The HeatGenius is a portable space heater rather than a central underfloor heating controller. This ceramic heater features a built-in programmable thermostat, multiple heat settings, and safety protections including overheat protection, thermal insulated wiring, cool-touch housing, and tip-over detection. A 2-hour auto-off timer prevents accidental extended operation. Honeywell markets this unit as capable of reducing heating costs by up to $276 annually when used to supplement central heating in specific rooms. The multi-directional heating design distributes warmth throughout a space, and the programmable thermostat allows scheduling to match occupancy patterns.

Who It’s Best For: Not suitable for underfloor heating systems. Best for supplemental room heating in bedrooms, offices, or living spaces where zone heating reduces whole-house heating loads. Useful for renters or temporary installations.

Pros: Portable and easy to relocate; programmable thermostat included; multiple safety features; potential energy savings through zone heating; ceramic heating element efficient; Honeywell brand reliability.

Cons: Completely unsuitable for underfloor heating; portable design means temporary installation only; consumes floor space; safety concerns with pets or children; cannot integrate with central heating systems; higher operating costs per BTU than central systems.

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Honeywell HeatGenius Ceramic Space Heater with Thermostat

Honeywell HeatGenius Ceramic Space Heater with Thermostat

Electric Space Heaters
Honeywell
amazon.com
In Stock
$78.79 $94.99 Save $16.20
Updated: 1 month ago
Price as of April 24, 2026 2:31 pm. We earn from qualifying purchases.
  • SPACE HEATER – The Honeywell HeatGenius Ceramic Heater provides 6 customized heat settings to give you control of your comfort. This personal heater features a programmable thermostat and easy to control, personalized comfort, for any room of your home.
  • SAFETY MATTERS: This large room heater offers multiple safety options including 3x Overheat Protection and thermal insulated wiring. It features cool touch plastic housing, tip over protection, and a 2 hour auto-off heat phase timer option.
  • INCREASE YOUR COMFORT – Always be comfortable, no matter what season it is. This air heater offers intelligent and powerful ceramic heating capabilities, so you, your room or floor area can be warm and comfortable, with just the touch of a button.
  • SMART SAVINGS – Worried about heating costs? An electric heater can help you save up to $276* in heating costs this year. A space heater for indoor use can help you save money while providing soothing warmth.
  • HONEYWELL QUALITY: Help improve heating and energy savings in your home, bedroom or office using a Honeywell portable heater. Honeywell offers whole room heaters, tower heaters and oscillating heaters.

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What Should You Look for When Choosing a Honeywell Thermostat for Underfloor Heating Control?

Temperature Sensing Capability: The most critical feature for underfloor heating is dual-sensor capability. Your thermostat must monitor both ambient room air temperature and floor surface temperature simultaneously. Single-sensor thermostats designed for forced-air heating cannot safely control radiant floors because they ignore floor temperature, risking overheating and damage to flooring materials. The best underfloor thermostats offer three control modes: ambient-only (for rooms where floor temperature is not critical), floor-only (for systems prioritizing surface comfort), and hybrid mode (which maintains comfortable room temperature while capping maximum floor temperature). This flexibility ensures your system adapts to different seasonal needs and room uses.

Voltage and Power Capacity: Verify your radiant floor system’s electrical specifications before purchasing. Most systems operate on either 120V or 240V circuits, and some thermostats support both. Check the maximum power wattage your thermostat can handle—radiant floor systems typically draw 15 to 30 amps depending on zone size. The TH115-AF-GA/U and the generic B08QJS8MV8 both support dual-voltage operation, making them versatile choices if you’re uncertain about your existing wiring. Undersized thermostats cannot safely handle radiant floor loads and may overheat or fail. Always verify your floor system’s specifications and match the thermostat’s amperage rating accordingly.

GFCI Protection: Ground Fault Circuit Interrupter (GFCI) protection is non-negotiable for safety. GFCI devices detect electrical leakage—typically caused by damaged insulation in floor heating cables—and instantly cut power to prevent electrocution. The National Electrical Code (NEC) requires GFCI protection on all 120V and 240V radiant heating circuits. Choose thermostats with built-in Class A GFCI (most sensitive to leakage) rather than relying on external GFCI breakers. Built-in GFCI provides redundancy: if the breaker fails, the thermostat’s GFCI still protects you. Models like the TH115-AF-GA/U and B08QJS8MV8 include integrated GFCI with manual test buttons, allowing you to verify protection monthly.

Programmability and Scheduling: Programmable thermostats reduce energy waste by automatically adjusting temperature during unoccupied periods or sleeping hours. Look for thermostats offering at least 5-2 day programming (separate weekday and weekend schedules) or full 7-day programming for maximum flexibility. Four daily periods—wake, leave, arrive, sleep—cover most household routines. Each period should allow independent temperature setpoints. Non-programmable models like the RTH111B or Pro 1000 require manual adjustment, wasting energy when occupants forget to lower temperatures during absences. For underfloor heating, which has slow thermal response (30 to 60 minutes to reach setpoint), pre-programming temperature changes ensures comfort without manual intervention.

Smart Home Integration and Remote Access: As of 2026, smart home integration is increasingly common but not essential for underfloor heating control. WiFi-enabled thermostats allow remote temperature adjustment via smartphone apps, learning algorithms that optimize scheduling, and integration with voice assistants. However, none of the six Honeywell products reviewed here offer smart home features—they are all traditional thermostats. If smart control matters to you, consider exploring whether Honeywell offers Evohome smart modules compatible with your chosen thermostat, or investigate third-party smart thermostats designed for radiant heating. Traditional thermostats like the TH115-AF-GA/U remain popular because they eliminate WiFi security concerns and require no internet connectivity.

Installation Compatibility: Before purchasing, confirm your thermostat is compatible with your radiant floor system’s existing wiring. Most systems use 2-wire or 3-wire connections. The RLV4305A1000 specifically mentions 2-wire non-polarized connections, simplifying retrofits. Verify whether your system requires a line-voltage thermostat (controls full electrical load directly) or a low-voltage thermostat (controls a relay that switches the main load). Radiant floor heating typically uses line-voltage thermostats. If your system has existing thermostats, match the connection type before upgrading. Mismatched wiring can damage both the thermostat and floor heating system.

Display and Controls: A clear, easy-to-read display and intuitive controls improve daily usability. Large LCD screens with backlighting (like the B08QJS8MV8) allow reading in various lighting conditions. Soft-touch buttons (RTH111B) prevent accidental adjustments compared to mechanical dials (Pro 1000). Digital displays show current temperature, setpoint, and programming status at a glance. Mechanical models like the Pro 1000 lack displays entirely, making them difficult to verify current settings. For households with elderly members or children, larger displays and simpler controls reduce confusion and accidental temperature changes.

Accuracy and Temperature Stability: Temperature accuracy affects both comfort and energy efficiency. The RLV4305A1000 offers ±0.27°F accuracy—exceptional for an affordable thermostat. The RTH111B provides ±0.5°C (±0.9°F) accuracy. For underfloor heating, accuracy within ±1°F is acceptable; tighter accuracy reduces temperature swings and improves comfort. TRIAC switching technology (used in the RLV4305A1000) eliminates the noise and temperature oscillation common in older relay-based thermostats, resulting in quieter operation and more stable floor temperatures.

Frequently Asked Questions

Can I use a standard wall thermostat for underfloor heating?

No, standard thermostats designed for forced-air heating cannot safely control underfloor systems. Radiant heating requires thermostats with floor sensors to monitor surface temperature and prevent overheating. Standard thermostats only measure room air temperature, ignoring floor conditions. This risks damaging flooring materials, voiding warranties, and creating safety hazards. Always use thermostats specifically designed for radiant heating, like the TH115-AF-GA/U or B08QJS8MV8.

What does GFCI protection do in an underfloor heating thermostat?

GFCI (Ground Fault Circuit Interrupter) detects electrical leakage caused by damaged insulation in floor heating cables and instantly cuts power to prevent electrocution. The Consumer Product Safety Commission (CPSC) recommends GFCI protection for all radiant heating circuits. Built-in GFCI thermostats provide redundant protection if your circuit breaker fails. Most models include manual test buttons to verify GFCI function monthly, ensuring your family’s safety.

How much can I save on heating costs using a programmable underfloor thermostat?

Programmable thermostats typically reduce heating energy consumption by 10 to 15 percent annually by automatically lowering temperatures during unoccupied periods and sleeping hours. Savings depend on your climate, home insulation, and occupancy patterns. Underfloor heating’s slow thermal response means pre-programming temperature changes ensures comfort without wasting energy on heating empty rooms. Actual savings vary; homeowners in cold climates see larger absolute dollar savings than those in mild climates.

Should I choose a 120V or 240V underfloor heating thermostat?

Check your radiant floor system’s electrical specifications—the thermostat voltage must match your circuit voltage. 240V systems deliver double the power of 120V at the same amperage, making them suitable for larger heating zones. 120V systems work for smaller areas. The B08QJS8MV8 supports both voltages, offering flexibility if you’re uncertain. Never force a 120V thermostat onto a 240V circuit or vice versa; mismatched voltage damages equipment and creates fire hazards.

Can I upgrade from a non-programmable to a programmable underfloor thermostat?

Yes, if your radiant floor wiring is compatible. Verify your existing thermostat’s wire connections (typically 2-wire or 3-wire) and match them to the replacement model. Programmable thermostats like the TH115-AF-GA/U or RLV4305A1000 use standard connections and install in place of older models. If your current wiring is outdated or damaged, an electrician may need to run new cable. Upgrading to programmable control typically costs $50 to $220 and pays for itself through energy savings within 1 to 3 years.

Do Honeywell underfloor thermostats work with smart home systems?

The six Honeywell products reviewed here do not include built-in smart home integration or WiFi connectivity. They are traditional thermostats requiring manual programming and wall-mounted operation. Honeywell offers separate smart home modules and integrations through its broader Evohome ecosystem, but these must be added separately. If smart control is essential, consult Honeywell’s current smart thermostat lineup or investigate third-party smart thermostats compatible with radiant heating systems.

Which Honeywell Underfloor Heating Thermostat Should You Buy?

Best Overall Choice: Honeywell TH115-AF-GA/U Radiant Heating Programmable Thermostat The TH115-AF-GA/U emerges as the best all-around choice for most homeowners installing or upgrading underfloor heating systems. Its three control modes (ambient-only, floor-only, and hybrid) provide flexibility for different room types and seasonal needs. The integrated floor sensor prevents overheating and protects expensive flooring materials. Built-in GFCI protection meets all electrical codes and includes a manual test function for monthly safety verification. Seven-day programmability with four daily periods reduces energy waste while maintaining comfort. Honeywell’s heritage and reliability ensure long-term performance. At approximately $218, this thermostat represents a solid mid-range investment that will likely serve your system for 10+ years without needing replacement.

Best Budget Option: Programmable Thermostat for House Radiant Underfloor Heating (B08QJS8MV8) For homeowners prioritizing cost without sacrificing essential features, the B08QJS8MV8 delivers exceptional value at under $100. Its dual-sensor design intelligently selects between air and floor temperature readings, and the self-adaptive logic learns your heating patterns over time. Dual-voltage support (120V/240V) accommodates most existing installations. The large LCD display with backlight clearly shows programming and temperature status. Built-in Class A GFCI with manual test function provides safety equivalent to premium models. Seven-day programmability and a 5-year warranty round out an impressive feature set. This model sacrifices brand recognition for affordability but delivers performance comparable to the TH115-AF-GA/U at less than half the price.

Best for Electric Resistance Heating: Honeywell Home RLV4305A1000 If your radiant floor system uses electric resistance heating (rather than hydronic), the RLV4305A1000 offers unmatched temperature stability and silent operation. Its TRIAC switching technology eliminates the clicking and noise common in relay-based thermostats, and the ±0.27°F accuracy prevents temperature swings. The 5-2 day programming structure suits most household routines. Simple 2-wire installation makes retrofitting existing systems straightforward. At approximately $55, this model is affordable for budget-conscious homeowners. However, lack of GFCI protection and absence of floor sensing limit its suitability for advanced radiant systems.

Avoid for Underfloor Heating: Honeywell TH1100DV1000/U Pro 1000, RTH111B, and HeatGenius The Pro 1000 and RTH111B are non-programmable thermostats lacking floor sensors and GFCI protection—essential features for safe, efficient underfloor heating control. These models suit basic supplemental heating or temporary installations but cannot reliably manage permanent radiant floor systems. The HeatGenius is a portable space heater, not a central heating controller, and is completely unsuitable for underfloor heating. Do not consider these three models for your radiant floor project.

Final Recommendation: For most homeowners, the Honeywell TH115-AF-GA/U represents the best combination of safety, performance, and reliability. Its purpose-built design, dual-sensor capability, GFCI protection, and 7-day programmability address all critical underfloor heating requirements. If budget is your primary concern and you have a straightforward installation, the B08QJS8MV8 offers 90% of the functionality at 40% of the cost. Verify your system’s voltage and amperage requirements before purchasing, confirm wire compatibility with your existing installation, and test GFCI protection monthly after installation to ensure ongoing safety. With proper thermostat selection and maintenance, your underfloor heating system will provide comfortable, efficient warmth for decades.

Related Articles: For additional energy management insights, explore how Amazon Smart Thermostat Alexa Hunches save energy in 2026, compare Honeywell Home X2S vs Ecobee Essential smart thermostats, or read our guide on smart home energy-saving tips for winter 2026. Learn about phantom load energy vampires and how to eliminate hidden energy waste in your home.