Finding The Right Thermostat for electric radiant floor systems ensures comfort, safety, and energy efficiency. Below is a quick comparison of well-regarded thermostats compatible with in-floor heating systems, followed by detailed reviews and a comprehensive buying guide.
| Product | Key Features | Sensing |
|---|---|---|
| Honeywell TH115-AF-GA/U | 7-day programmable, floor sensor, GFCI | Floor |
| OJ Microline UDG | 7-day programmable, Class A GFCI, dual sensing | Air & Floor |
| SunTouch SunStat ConnectPlus | Wi‑Fi, touchscreen, voice control, floor & air sensing | Air & Floor |
| OJ Microline UTN4 | Non‑programmable, Class A GFCI, dual voltage | Air & Floor |
| Schluter Ditra-Heat-E-RS1 | Smart app, energy tracking, GFCI, voice assistant | Floor |
Content Navigation
Honeywell TH115 Radiant Thermostat
The Honeywell TH115-AF-GA is a line‑voltage thermostat designed for electric radiant floor heating. It offers 7-day programmability and is intended for 120/240V systems. A dedicated floor sensor provides direct floor temperature control to protect delicate flooring and maintain consistent surface warmth.
Honeywell positions this model for reliability and compatibility with electric heating loads. The design supports scheduled temperature setbacks and daytime/winter patterns typical for programmable thermostats. The model number and brand provide common support resources and documentation for wiring and installation professionals.
OJ Microline UDG Programmable Thermostat
The OJ Microline UDG is a feature-rich programmable thermostat for heated floors. It includes a Class A GFCI and supports 120V/240V line voltages. Dual sensing (air and floor) allows installers to configure control logic that prioritizes either floor temperature or ambient air temperature.
Call 888-896-7031 for Free Local HVAC Quotes – Compare and Save Today!
Key features include an intuitive 7-day program, child lock, energy consumption readout, manual override, and floor‑limiting settings for laminate and engineered wood. OJ provides a flooring sensor and a warranty with USA product support, making it suitable for a wide range of surfaces including tile, marble, carpet, concrete, and wood.
SunTouch SunStat ConnectPlus Smart Thermostat
The SunTouch SunStat ConnectPlus is a modern smart thermostat with a 4.3″ touchscreen and Wi‑Fi, voice assistant integration (Alexa and Google). It supports floor and air sensing and features SmartStart technology that adjusts run times so floors reach scheduled temperatures on time.
Its feature set includes a 7-day programmable schedule, away mode, energy monitoring, floor max settings to protect flooring types, outdoor temperature display, and email alerts. Remote access and automation make this option suited to users who want app control and smart home integration for radiant floor heating.
OJ Microline UTN4 Non-Programmable Thermostat
The OJ Microline UTN4 is a digital, non‑programmable thermostat for radiant floor heating. It includes a built‑in Class A GFCI as required in many underfloor installations and is cUL listed for North America. The unit supports multiple voltages (120/208/240V) and is intended as a simple plug‑and‑play control.
Call 888-896-7031 for Free Local HVAC Quotes – Compare and Save Today!
Because it is non‑programmable, the UTN4 provides straightforward temperature selection and fast installation for users who prefer manual control or have simpler heating needs. Dual sensing capability enables choosing between air or floor sensor feedback, which is useful for different installation requirements and flooring materials.
Schluter Ditra-Heat-E-RS1 Smart Thermostat
The Schluter Ditra-Heat-E-RS1 is a smart thermostat engineered for use with Ditra‑Heat systems and other compatible 120/240V floor heating cables. It offers app control, energy tracking, a mirror finish design, and voice assistant compatibility, bringing smart home features to radiant floor heating.
Designed for systems up to 15 amps (with optional power modules for larger loads), it includes built‑in floor sensors and GFCI protection. The companion app provides scheduling, usage insights, and remote control—useful for energy-conscious users or those wanting centralized control within smart home ecosystems.
Buying Guide: Choosing The Right Floor Heater Thermostat
Choosing a thermostat for radiant floor heating depends on safety compliance, control needs, system size, and flooring type. Below are the primary considerations to evaluate before purchase.
Heating System Compatibility
- Voltage And Load: Confirm thermostat supports your system voltage (120V, 208V, 240V) and amperage. Typical thermostats list maximum wattage or amp ratings.
- Heat Cable Or Mat Type: Ensure the thermostat is compatible with cable, mat, or thin-set systems used in your installation. Some thermostats are optimized for specific brands or product lines.
Sensors And Control Strategy
- Floor Sensor vs Air Sensor: Floor sensors measure surface temperature and protect sensitive flooring. Air sensors control ambient room temperature. Dual-sensing thermostats offer configurable logic that can prioritize one input.
- Sensor Placement: Proper placement of the floor sensor between heating elements (not on top of them) is essential for accurate readings and to avoid hotspots.
Safety Features
- Built‑In GFCI: Many locales require Class A GFCI protection for underfloor heating. Thermostats with integrated GFCI simplify wiring and compliance.
- Floor Max Limits: Look for thermostats that allow setting maximum floor temperatures for laminate, engineered wood, or other sensitive materials.
Control And User Experience
- Programmable Schedules: 7‑day programming and adaptive start features reduce energy use while maintaining comfort.
- Touchscreen Vs Simple Dial: Touchscreens and smart displays provide more features and easier scheduling; non‑programmable digital units are simpler to use for basic needs.
- Remote Access & Smart Home: Wi‑Fi thermostats with apps and voice control are useful for remote adjustments and integration with existing smart systems.
Installation And Wiring
- Professional Wiring: Line‑voltage thermostats often require a dedicated circuit and should be installed by a qualified electrician unless you are experienced with household line work.
- Compatibility With Existing Wiring: Check the thermostat’s terminal layout and wiring diagram. Some models require neutral, others do not; line‑voltage controls typically switch the hot feed directly.
System Size And Expandability
- Load Capacity: Match the thermostat’s amp rating to your floor heating circuit. For larger floor areas, consider thermostats with additional power modules or a separate relay.
- Multiple Zones: Large homes may require multiple thermostats or a zoned control system; verify how the thermostat fits into a multi‑zone plan.
Flooring And Temperature Limits
- Floor Type Settings: Different materials handle temperatures differently. Ensure the thermostat supports floor‑type maximums and offers protection for laminate or engineered wood.
- Sensor Calibration: Confirm sensor accuracy and the ability to offset readings if needed for specific installations.
Energy Monitoring And Efficiency
- Energy Use Feedback: Thermostats with consumption readouts or app-based tracking can help identify usage patterns and reduce costs.
- Adaptive Start Or SmartStart: Features that learn and auto‑adjust run times can ensure rooms reach target temperatures on schedule while minimizing total runtime.
Warranty, Support, And Certification
- UL/cUL Listings: Verify safety listings for North American installations.
- Warranty & Support: Manufacturer support and a multi-year warranty are useful, particularly for built‑in GFCI models where replacement can be more involved.
Comparison Perspectives
- Simple vs Advanced Control: Non‑programmable thermostats (like the OJ UTN4) fit users who want basic set-and-forget control. Programmable and smart models (OJ UDG, SunTouch, Schluter) suit those wanting scheduling and remote management.
- Safety & Code Compliance: Models with integrated Class A GFCI streamline compliance for many underfloor systems compared to separate GFCI installations.
- Smart Home Integration: If app control and voice commands matter, prioritize Wi‑Fi thermostats with proven integration and secure cloud support.
- Floor Protection: For laminate or engineered wood, choose thermostats with explicit floor max settings and accurate floor sensor control.
Use this guide to match product specifications to your installation requirements, flooring type, and desired control features. When in doubt, consult installation manuals and a licensed electrician to ensure safe, code‑compliant wiring and sensor placement.
Tips for Getting the Best HVAC Prices
- Prioritize Quality Over Cost
The most critical factor in any HVAC project is the quality of the installation. Don’t compromise on contractor expertise just to save money. - Check for Rebates
Always research current rebates and incentives — they can significantly reduce your overall cost. - Compare Multiple Quotes
Request at least three estimates before making your choice. You can click here to get three free quotes from local professionals. These quotes include available rebates and tax credits and automatically exclude unqualified contractors. - Negotiate Smartly
Once you've chosen a contractor, use the proven strategies from our guide — How Homeowners Can Negotiate with HVAC Dealers — to get the best possible final price.