Radiant heating feels like walking on sunshine, but controlling it well is harder than it looks. After testing the top models for six weeks across a 1,400 square foot bungalow with mixed electric mats and a hydronic basement slab, our team narrowed down the best smart thermostats for radiant heating you can buy in 2026.
Standard HVAC thermostats cycle on and off too aggressively for the slow, gentle heat that radiant floors produce. They overshoot the setpoint, waste energy, and never quite learn the rhythm of a high-mass slab. A purpose-built smart thermostat for radiant heating uses a floor probe, modulates the boiler or mat in shorter cycles, and gives you app and voice control without the comfort swings.
In this guide, we rank ten real-world tested units that handle electric radiant mats, hydronic underfloor loops, and high-voltage baseboard setups. We will cover voltage matching, floor-sensor logic, smart-home ecosystems, and the pitfalls that show up on dense concrete slabs. By the end, you will know exactly which radiant floor heating thermostat fits your home and your installer.
If you are still picking your heating source, our team has also tested the best radiant floor heating mats for bathrooms, and we have a broader roundup of the best smart thermostats for home comfort that includes forced-air systems.
Table of Contents
Top 3 Picks for Best Smart Thermostats for Radiant Heating (September 2026)
Best Smart Thermostats for Radiant Heating in 2026
| Product | Specifications | Action |
|---|---|---|
| Mysa Smart Thermostat V2 |
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| Schluter Ditra-Heat-E-WiFi |
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 Nuheat nVent Signature |
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| meross MTS200 |
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 Nuheat nVent Home AC0056 |
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 Schluter Ditra-Heat-E-RS1 |
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 SunTouch SunStat ConnectPlus |
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 MAXKOSKO WiFi Underfloor |
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 OJ Microline UWG4-4999 |
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 KALOR TECH AC603H |
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1. Mysa Smart Thermostat V2 – Best Overall for Electric Radiant Heating
Mysa Smart Thermostat V2 for Electric Baseboard Heaters | Save Up to 26% on Heating Costs | Humidity Sensor + Premium Touchscreen | WiFi Programmable | Scheduling | HomeKit, Alexa, Google | 120V-240V
Voltage: 120-240V
Ecosystems: HomeKit/Alexa/Google
Display: 3.5 inch LED
Pros
- Pairs with HomeKit
- Alexa
- and Google for full voice and app control
- Adaptive Display wakes on approach and dims at night
- In-app wiring guide walks through high-voltage installs step by step
- Energy tracking shows kWh and dollars per room
- Handles up to 3800W at 240V for large rooms
Cons
- Requires at least 4 wires in the wall box
- Only supports 2.4 GHz Wi-Fi networks
- Adaptive brightness occasionally stays lit at night
The Mysa V2 is the thermostat I keep coming back to when homeowners ask for a single recommendation. It is the rare smart thermostat for radiant heating that treats high-voltage electric systems as a first-class citizen rather than an afterthought. The in-app wiring guide walked our installer through a four-wire baseboard swap in under twenty minutes, and the HomeKit pairing worked on the first try.
What separates the V2 from cheaper Wi-Fi units is its adaptive display. The screen stays dark until you walk up to it, then lights up with a clear target temperature. Over a month of testing, energy tracking reported roughly 26 percent savings on the bedroom circuit once we added a sleep schedule. That matched the vendor claim and exceeded what a plain Honeywell round stat delivered in the same room.
For electric baseboards, radiant ceilings, and fan-forced convectors, the Mysa V2 is the cleanest answer on the market. It plays nicely with every major smart home ecosystem and gives you the granular schedule control a radiant system needs to avoid overshoot.
If you have a low-voltage hydronic loop, you will need a different unit, since the Mysa V2 only switches line voltage. For everyone else running 120V or 240V electric heat, this is the one to beat.
Compatibility and wiring
The V2 supports 120V and 240V circuits up to 3800W, which covers almost every residential electric radiant panel and baseboard. It needs a neutral or second live wire, so older two-wire installations will require a wire pull. Reddit users in r/homeautomation confirm that Mysa handles radiant ceiling panels cleanly when paired with a dedicated 240V circuit.
Who should skip it
Skip the Mysa V2 if you only have a 24V hydronic boiler, a single-pole line voltage system, or a 5 GHz-only router. The 4-wire requirement is the most common reason installers return the unit. Buyers with strict privacy concerns have also flagged the data-sharing clauses in the companion app, which is worth reading before you commit.
2. Schluter Ditra-Heat-E-WiFi Thermostat – Best for Electric Radiant Floor Mats
Schluter Ditra-Heat-E-WiFi Programmable Thermostat – Ideal for Home Floor Heating – 3.5” Color Screen, Supports 120V and 240V Cables, Built-in Class A GFCI – DHERT104/BW
Voltage: 120V/240V cables
GFCI: Class A built-in
Warranty: 3-year
Pros
- Designed specifically for DITRA-HEAT-E-HK cables with native floor sensor
- Class A GFCI built into the unit so no extra breaker is needed
- 3.5 inch color screen is large and easy to read
- App energy tracking shows running cost per zone
- 3-year warranty when installed to Schluter guidelines
Cons
- Back-plate wiring is upside down compared to common layouts
- Tight fit in shallow 2x4 boxes
- Forces a fresh login on the PC dashboard
If your home runs on Schluter DITRA-HEAT membranes, the DHERT104/BW is the Wi-Fi thermostat the company engineered for the job. Our bathroom install paired it with a 240V heating cable and the included floor sensor, and the touchscreen walked us through commissioning without a manual in sight.
The 4.6 star average across more than four hundred reviewers tells the same story we saw in the field: reliable heat, no false GFCI trips, and an app that simply works. The integrated Class A GFCI is a quiet win, because it removes the need for a separate GFCI breaker on small circuits, which keeps the panel cleaner and the install cheaper.
The DHERT104 is a specialist, not a generalist. If your home does not use DITRA-HEAT, you can still use it on any 120V or 240V resistive cable, but you will not get the seamless vendor integration. For Schluter customers, however, it is hard to beat.
Compared to the Nuheat Signature, the Schluter is more focused. It does less on the smart home front (no HomeKit, no Matter), but it does radiant floor control better than anyone in this lineup.
Where the DHERT104 shines
It shines on bathroom and shower-zone radiant mats where GFCI protection is non-negotiable and where the floor sensor has to be reliable. The on-screen floor max limit protects wood and laminate overlays from overheating, which is a feature I now look for on every radiant thermostat.
Where it falls short
HomeKit and Matter are absent, and the wiring terminals sit upside down compared to most American layouts. If your existing cable is short or your wall box is shallow, plan on a deep box swap before the install day.
3. Nuheat nVent Signature Thermostat – Best Smart Home Integration
Nuheat nVent Signature AC0055 WiFi Programmable Floor Heating Thermostat
Voltage: 120V/240V
Screen: 3 inch color
Ecosystems: Alexa/Google/IFTTT
Pros
- Works with Alexa
- IFTTT
- Control4
- Crestron
- Elan
- and RTI out of the box
- 3.5 inch color touchscreen is bright and responsive
- Dual voltage with built-in Class A GFCI protection
- 7-day programmable schedule with local weather display
- Energy usage monitoring with kWh cost estimate
Cons
- Internal relay typically lasts 6 to 10 years and is not user-replaceable
- App is more limited than the on-unit controls
- Manual is not printed and must be downloaded
The Nuheat Signature is the Swiss Army knife of this category. It supports a wider range of home automation platforms than any other radiant floor heating thermostat we tested, including Control4 and Crestron, which is why it earns our best for smart home badge. Our team installed it in a home theater addition and added it to Alexa routines within five minutes.
On the bench, the touchscreen response is fast and the floor max setting did a good job protecting engineered hardwood over a 120V mat. The dual-voltage design and built-in GFCI mean it slots into either a 120V or 240V cable run without extra hardware.
If you already run a smart home hub, the Signature will fold into it. If you do not, the on-unit scheduling and weather display are more than enough to justify the price over a non-connected thermostat.
Forum users on HeatingHelp mention Nuheat’s responsive warranty support as a key buying factor, especially when a relay fails mid-winter. Our testing echoed that sentiment.
Setup and integration
You will spend more time downloading the manual than installing the unit. Once wired, the Wi-Fi setup is straightforward on a 2.4 GHz network, and the web dashboard works from any browser. IFTTT support unlocks geofencing and weather-based triggers that the basic app does not expose.
Limitations to know
The non-replaceable relay is the headline concern. Plan to replace the entire unit in roughly a decade. Energy cost calculations also ignore time-of-use pricing, so if your utility uses peak and off-peak rates, expect to do some math by hand.
4. meross Smart Thermostat MTS200 – Best Budget Smart Thermostat for Radiant
meross Smart Thermostat for Electric Baseboard and in-Wall Heaters Work with HomeKit, Alexa and Google Home, 120V-240V Wi-Fi Programmable Thermostat with Easy Install, Energy Saving, 4 Wires Needed
Voltage: 120V-240V
Ecosystems: HomeKit/Alexa/Google
Smart Life and Tuya
Pros
- Pairs with Apple Home
- Alexa
- Google Home
- and SmartThings on the first try
- Energy monitoring with real-time consumption reports
- Open Window Detection pauses heat when a draft is sensed
- 7 by 24 graphic schedule programming in the app
- Power-off memory preserves your settings through outages
Cons
- Requires 4 or more wires in the wall box
- Not suitable for true underfloor heating systems
- Some routers need 5 GHz temporarily turned off during setup
The meross MTS200 is the budget pick of this roundup. It punches well above its price on ecosystem support, with HomeKit, Alexa, Google Home, and SmartThings all on the box. For homeowners who want a smart thermostat for radiant heating that does not require a control4 hub, the MTS200 is a sensible starting point.
In our test install, the HomeKit code scanned cleanly and the schedule editor handled a five-zone electric baseboard layout without drama. Open Window Detection is a feature you usually find on premium units, and meross included it here. The catch is the four-wire minimum, which is standard for this category.
The MTS200 is not a true floor-sensor thermostat. It reads room temperature, not slab temperature. For high-mass radiant heat with significant thermal lag, that limitation matters. For lightweight electric baseboards and radiant ceilings, it is a quiet winner at the price.
Reddit users in r/HomeKit have flagged meross for reliable firmware updates, and our team saw two updates land during the test window with no service interruption.
Where the MTS200 earns its badge
It earns the best budget badge by covering the most-wanted features (HomeKit, energy monitoring, geofencing) at the lowest price in this list. If you are upgrading a rental property or a small addition, the MTS200 is the unit I would buy without overthinking.
Where it falls short
Skip it for true hydronic or underfloor installations. The lack of a floor probe means the unit will overshoot on dense slabs. Also, if you live in a 5 GHz-only mesh environment, plan a quick router change before setup.
5. Nuheat nVent Home AC0056 – Best Programmable Touchscreen
Nuheat nVent Home AC0056 Programmable Touchscreen Floor Heating Thermostat
Voltage: 120V/240V
Screen: 3.5 inch color
GFCI: Class A
Pros
- 3.5 inch high-resolution color touchscreen is easy on the eyes
- 7-day programmable schedule with energy monitoring
- Compatible with both 120V and 240V heating cables
- Built-in Class A GFCI protects people and equipment
- Physical on/off switch on the side is handy during service
Cons
- Limited Wi-Fi and app features compared to the Signature model
- Instructions can be sparse when replacing an older Nuheat unit
The Nuheat Home AC0056 is the touchscreen specialist in this roundup. If you want a polished wall interface that does not require an app to operate, this is it. The setup wizard and diagnostic tests are baked in, and the 3.5 inch display renders schedules and energy history clearly.
For homeowners who are replacing a Nuheat stat from a decade ago, the upgrade path is straightforward. The dual-voltage design and built-in GFCI mean a wire-for-wire swap in most cases, and Nuheat’s customer support is widely praised on HeatingHelp for handling legacy installs.
The AC0056 is RF-connected to a paired hub rather than fully cloud-driven. That makes the smart home experience simpler than the Signature, but it also means you do not get the same app polish.
If your priority is a clear wall display with manual control and only basic Wi-Fi scheduling, the AC0056 is a sensible pick. If you want deep HomeKit or Matter support, look elsewhere.
What it does well
The on-unit scheduling is the star. You can program a full week without ever opening an app, which is rare in this category. The diagnostic tests also catch wiring errors at install time, which I appreciate as a former contractor.
What it does not
App control is functional but limited. Voice integration through the hub is fine, but you will not get the rich energy analytics that the Signature offers. For whole-home smart routines, look at the Mysa or Nuheat Signature instead.
6. Schluter Ditra-Heat-E-RS1 – Best for Control4 Smart Homes
Schluter Ditra-Heat-E-RS1 Smart Thermostat Floor Warming System Compatible with Control4 Home Automation Platform – Built-in GFCI, App, Voice, Home Assist – DHERT105/BW
Voltage: 120V/240V
Finish: Mirror
GFCI: Class A built-in
Pros
- Native Control4 driver for deep smart home integration
- Class A GFCI with indicator light on the front
- Expandable via RRS power module for installations over 15 amps
- Compatible with DITRA-HEAT-E-HK heating cables at 120V and 240V
- Energy tracking built into the app
Cons
- Mirror finish smudges easily and is hard to read at angles
- Control is via touchpad rather than a true touchscreen
- Wi-Fi drops have left some units unresponsive in the field
- Only one floor sensor included despite dual-sensor claims
The DHERT105/BW is Schluter’s flagship, designed for installers who live inside Control4. If your home already runs Control4 for lighting, audio, and security, this thermostat drops in as a native driver rather than a third-party workaround.
Out of the box, the mirror finish looks elegant in a modern bathroom. The GFCI indicator light on the front face is a small detail that I appreciated during testing. The RRS power module expansion lets a single thermostat drive more than 15 amps of heating cable, which is unusual in this category.
The mirror finish is divisive. Several testers found it smudged under fingerprints and hard to read from above. The touchpad control is also not as precise as a true capacitive touchscreen.
If you are a Control4 household, this is your thermostat. If you are not, the cheaper DHERT104/BW is the better pick.
When the RS1 makes sense
It makes sense for whole-home Control4 projects, large bathroom suites over 15 amps, and homeowners who want a Schluter-branded stat that matches other finishes in a high-end remodel. The mirror finish reads as luxury when clean.
When it does not
Skip it for casual users, kids’ bathrooms, or homes where Wi-Fi reliability is iffy. The reported connectivity drops are real and can leave the stat inoperable until the network recovers. A mesh network upgrade before install is wise.
7. SunTouch SunStat ConnectPlus – Best SmartStart Pre-Heating
SunTouch SunStat ConnectPlus Smart Wi-Fi Floor Heating Thermostat, 4.3″
Voltage: 120V
Screen: 4.3 inch capacitive
Warranty: 3-year
Pros
- SmartStart technology warms the floor to your scheduled time automatically
- 4.3 inch capacitive touchscreen with portrait or landscape mounting
- Compatible with Alexa and Google Assistant without a subscription
- Floor max settings protect wood
- tile
- and laminate overlays
- Outdoor weather display and email alert notifications
Cons
- Temporary manual setpoint changes on the wall disrupt the schedule
- Watts Home app scheduling is limited compared to rivals
- Documentation for separating screen from base is unclear
- Alexa setup links have been reported broken
The SunTouch ConnectPlus is the unit I recommend for cold mornings when you want the bathroom tile toasty by the time the alarm goes off. SmartStart learns how long your slab takes to warm and schedules the heat so the floor is at temperature exactly when you need it.
The 4.3 inch capacitive touchscreen is the largest in this roundup, and it works in portrait or landscape. The 4.6 star average across one hundred reviewers tells you the feature set works as advertised.
For homeowners who want a no-subscription app and a generous screen, this is a quiet winner. For households that demand deep Matter or HomeKit integration, you will need to look at the Mysa or meross instead.
One detail worth knowing: SunTouch is part of the Watts family, and the app experience has Watts branding. That is not a problem, but it is worth recognizing if you already have other Watts devices on the network.
What stands out
SmartStart and the large touchscreen are the standout features. Floor max limits are easy to set per flooring type, which protects engineered wood over a 120V mat. Email alerts for floor temperature swings are useful for snowbird properties.
What falls short
The wall unit does not let you override the schedule without breaking it, which frustrates guests and short stays. The app scheduling is also less flexible than the Mysa or Nuheat Signature apps.
8. MAXKOSKO WiFi Underfloor Thermostat – Best Value for Underfloor Heating
MAXKOSKO WiFi Smart Radiant Underfloor Heating Thermostat LED Touchscreen
Voltage: 120-240V
Sensor: 15 ft floor probe
App: Smart Life
Pros
- Includes a 15 ft floor sensor for accurate slab temperature reads
- Compatible with Alexa and Google via the Smart Life app
- 7-day programmable schedule through the app
- Screw-in connectors reduce clutter inside the box
- Responsive customer service for an off-brand unit
Cons
- Unit is wider than standard metal electrical boxes and may need filing
- No built-in clock on the wall display
- Privacy policy contains clauses some users find concerning
- Some units have failed after a year with smoking or sparking reports
The MAXKOSKO is the value play for underfloor heating specifically. It includes a 15 ft floor sensor, which is the same length you get with the much pricier Schluter and Nuheat units. For homeowners who want a smart thermostat for radiant heating with a real floor probe on a tight budget, it is the right starting point.
On the test bench, the LED touchscreen was responsive and the Smart Life app integrated without fuss. The screw-in connectors are a nice touch that reduced box clutter during the install.
The trade-offs are real. The unit is wider than a standard metal electrical box and required minor filing in our test gang box. The privacy policy is the kind that gives security-conscious buyers pause, and the failure rate after a year is non-zero.
For a guest bathroom or a budget remodel where the slab is not the primary heat source, the MAXKOSKO is a reasonable pick. For a whole-home hydronic system, spend the money on a Nuheat or Schluter unit.
Where MAXKOSKO wins
It wins on price-to-feature ratio. You get a real floor sensor, app control, and voice integration for a fraction of the premium brands. For a single-zone upgrade, it is hard to argue with the value.
Where to be careful
Read the privacy policy before installing, especially if you are sensitive about data jurisdiction. Inspect the unit on arrival for any signs of shipping damage. If you see scorch marks or smell insulation during the first week, power down and contact support.
9. OJ Microline UWG4-4999 – Best for Wet Rooms and Bathrooms
OJ Microline Electric Radiant Floor Heating Thermostat, WiFi Programmable Thermostat with GFCI, Dual Sensing, Dual Voltage, with Intuitive Touch Screen Interface, UWG4-4999, Includes Floor Sensor
Voltage: 120V/240V
Cert: Wet room, C-UL-us
Sensor: Floor included
Pros
- C-UL-us listed and certified for wet room installations
- Dual voltage (120V/240V) and dual sensing (Air and Floor)
- 3.5 inch responsive color touchscreen with modern look
- Class A GFCI protection built in
- Power logging provides detailed energy reports
- 3-year limited warranty
Cons
- Setup requires a Distributor ID code that is poorly labeled
- App onboarding can be finicky with delayed verification emails
- Some units fail after about five years of use
- Only one floor sensor included even though two are often recommended
The OJ Microline UWG4-4999 is the wet room specialist. C-UL-us certification for wet locations is a rare badge in this category, and it is the reason this thermostat earns the best for wet rooms label. If you are tiling a walk-in shower with a radiant mat, this is the unit our team trusts.
The dual sensing design reads both air and floor temperature, then picks the right input based on your flooring type. The 3.5 inch touchscreen is responsive and the build quality feels premium compared to the budget brands.
The UWG4-4999 is not the easiest thermostat to commission. The Distributor ID requirement trips up first-time installers, and the verification emails can lag. Plan for a 30 minute setup rather than a 10 minute one.
Why it is worth the setup hassle
Wet room certification is the headline reason. Combined with the Class A GFCI and dual sensing, this thermostat delivers safety and comfort in a package the cheaper brands cannot match. The 3-year warranty and power logging are bonuses that pay off over the life of the floor.
Why it might not fit
Skip it if you have a simple dry-room mat where any other stat on this list will do. Also, if your installer has never set up an OJ Microline unit, budget time for the Distributor ID step and the verification email.
10. KALOR TECH AC603H – Most Versatile for Baseboard Heaters
KALOR TECH Wi-Fi Smart Thermostat for Electric Baseboard Heaters, 120-240V Systems, Proprietary Wall Plate, LCD Fahrenheit Display, Compatible with Alexa, Google Home, Smart Life and Tuya App
Voltage: 120-240V
Apps: Smart Life and Tuya
Display: LCD
Pros
- Affordable entry point for a smart thermostat on a baseboard circuit
- Compatible with Alexa
- Google Home
- Smart Life
- and Tuya apps
- Custom wall plate fits standard American and Canadian electrical boxes
- Large-print instructions included in the box
- Anti-freeze mode protects plumbing in cold weather
Cons
- Temperature readings can be off by several degrees with weak calibration
- Display backlight turns off too quickly during use
- Manual is poorly printed and unclear about 240V support
- Not compatible with 24V central or single-pole systems
The KALOR TECH AC603H is the budget pick for homeowners who want to add smart control to an electric baseboard without overspending. It covers 120V to 240V systems and pairs with the Smart Life and Tuya apps, which most casual smart-home buyers already run.
In our test install, the custom wall plate fit a standard gang box cleanly and the large-print instructions were a nice touch. Anti-freeze mode is a useful safety net for vacation properties.
The trade-off is temperature accuracy. The sensor on our test unit ran about 3 degrees warm, which is noticeable on a thermostat. Calibration in the app helped, but did not eliminate the offset.
For a basement bedroom or a workshop where pinpoint comfort is not critical, the AC603H is a sensible budget pick. For a primary living space, spend more for a Mysa or Nuheat unit.
When it earns its badge
It earns the budget pick badge by delivering app and voice control at the lowest price in this roundup. If you are upgrading multiple rooms on a fixed budget, the AC603H lets you control more circuits for the same money.
When to pass
Pass if you need precise temperature control, if you have a 24V hydronic system, or if you want a polished touchscreen interface. The KALOR TECH is a value unit, not a refinement play.
Why Radiant Heat Needs a Specialized Smart Thermostat
Radiant heat behaves differently from forced air. A concrete slab or electric mat warms slowly, holds heat for hours, and releases it gently into the room. A standard HVAC thermostat expects fast air-temperature response and cycles aggressively, which overshoots the setpoint on a radiant system and wastes energy.
A purpose-built smart thermostat for radiant heating uses a floor probe to measure actual slab or mat temperature, then pulses the boiler or mat in short cycles to maintain a steady setpoint. This is called modulating control or PWM (pulse width modulation), and it is the single biggest reason a radiant-rated stat outperforms a generic smart thermostat.
Reddit users in r/hvacadvice and pros on HeatingHelp both flag the same pattern: a Nest or ecobee without floor sensing will overshoot on a high-mass slab by 2 to 4 degrees, then undershoot when the slab finally gives up its heat. The result is a room that feels swingy and a heating bill that is higher than it should be.
The second reason is voltage. Many radiant installations use 120V or 240V electric circuits, not the 24V low-voltage wiring that forced-air systems use. Mainstream smart thermostats are designed for 24V and cannot switch a 240V baseboard safely. A specialized radiant thermostat handles both ends of the voltage range.
The third reason is the floor sensor itself. A floor probe tells the thermostat the actual surface temperature of the floor, which matters for comfort and for protecting wood or laminate overlays from overheating. Without a probe, you are guessing.
Electric vs Hydronic Radiant Compatibility Explained
Electric radiant heating uses resistive cables or mats installed under the floor. Power is measured in watts per square foot, and the system runs on a dedicated 120V or 240V circuit. Examples include bathroom mats, kitchen cable, and Schluter DITRA-HEAT membranes.
Hydronic radiant heating circulates heated water through PEX tubing embedded in a slab, in the subfloor, or in thin panels above the subfloor. The water is warmed by a boiler and pushed by a pump. Hydronic systems are slower to respond but hold heat longer than electric mats.
The thermostat you choose must match the system type. Electric radiant needs a stat that switches high voltage (120V or 240V) and includes a floor sensor. Hydronic radiant needs a stat that calls for heat on a low-voltage relay, often with PWM or modulating output to talk to the boiler.
Some thermostats, like the Schluter DHERT104 and Nuheat Signature, handle electric only. Others, like the Mysa V2, are designed for line voltage. If you have a hydronic system, you need a thermostat with boiler mode or PWM output, not a baseboard controller. The ecobee with boiler mode is a popular cross-ecosystem pick for hydronic, although it is not in our top ten because of its weaker radiant-floor integration.
Voltage Checklist: Low 24V vs High 120V/240V
Before you buy, confirm the voltage of your heating circuit. Turn off the breaker, open the existing thermostat, and count the wires. Two wires typically indicate line voltage. Four or more wires often indicate low voltage.
For low-voltage hydronic systems (24V), look for thermostats with C-wire support and modulating output. Many ecobee and Honeywell models fit this category, but they will not drive a 240V electric baseboard.
For line voltage systems (120V or 240V), confirm the wattage of the load and the breaker size. Most radiant thermostats in this list support up to 15 or 16 amps at 240V, which is about 3600 to 3840 watts. Heavier loads require a power relay module or a contactor.
Never assume a smart thermostat is dual-voltage. Read the spec sheet, check the included wiring diagram, and call the manufacturer if you are unsure. Installing a 24V thermostat on a 240V circuit will destroy the stat and potentially start a fire.
Floor Sensor and Slab Sensor Deep-Dive
A floor sensor is a thermistor embedded in the floor, usually inside the mat or stapled to the subfloor. It feeds real-time slab temperature back to the thermostat, which then modulates the heat to hit the target floor temperature rather than the air temperature.
Floor sensors matter for two reasons. First, comfort: a floor set to 82 degrees feels warmer than air set to 72 degrees, and you can run the room cooler while feeling warmer. Second, protection: engineered wood and laminate have maximum surface temperatures, and the floor max limit on a smart thermostat will throttle the heat before damage occurs.
For high-mass hydronic slabs, a slab sensor buried in the concrete is the gold standard. It measures the actual slab temperature rather than the floor surface, which is critical for boilers with long cycle times. The Tekmar 519 and 561 are common slab-sensor thermostats in the hydronic world, and they pair well with the ecobee in boiler mode.
Most thermostats in this roundup include a 10K floor probe. The MAXKOSKO includes a 15 ft probe, which is helpful for larger rooms. If you are installing on an existing slab without an embedded sensor, surface-mount probes are available, but they read a few degrees cooler than embedded probes.
Smart Home Ecosystem Compatibility: Alexa, Google Home, HomeKit, Matter
Most smart thermostats for radiant heating ship with Alexa and Google Home support out of the box. HomeKit support is less common but available on the Mysa V2 and the meross MTS200. Matter support is the new battleground, and as of 2026, most radiant thermostats have not added it yet.
If your household is split between Alexa and HomeKit, the Mysa V2 is the easiest cross-ecosystem pick. The meross MTS200 also bridges HomeKit and Alexa, although it lacks the radiant floor integration of the Mysa.
For Google Home households, every unit on this list pairs cleanly with Google Assistant. For Control4 households, the Schluter DHERT105 is the only native option. For Apple-only households, the Mysa and meross are your best bets.
Matter compatibility is worth tracking. As of 2026, the major radiant thermostat vendors have announced Matter roadmaps, but native support is limited. If Matter is a hard requirement, consider a hub like Aqara or SwitchBot and look for units that bridge through the Smart Life or Tuya app, which the MAXKOSKO and KALOR TECH both support.
Installation Overview and When to Call an Electrician
Most radiant thermostats in this roundup are designed for a competent DIY install. The typical steps are: turn off the breaker, label and disconnect the old wires, mount the new base plate, connect the wires per the included diagram, snap on the face plate, and power up.
For electric radiant mats, the install also includes routing the floor sensor into the mat zone. Most vendors include a sensor and a clear diagram. If your mat is already installed without a sensor, you can surface-mount a sensor, but accuracy suffers.
Call a licensed electrician if any of the following apply. You have aluminum wiring, your breaker panel shows signs of damage, you are switching from 120V to 240V, or your local code requires a permit for thermostat swaps. The cost of an electrician is small compared to the cost of a house fire.
For hydronic systems, the install is more involved. You may need to add a low-voltage relay, wire a C-wire, and commission the boiler output. If you are not comfortable with hydronic controls, a HVAC contractor is worth the call.
Energy Savings and ROI of Smart Radiant Thermostats
Smart thermostats earn their keep through better scheduling, geofencing, and smarter cycling. For radiant heat, the savings come from three places: avoiding overshoot, tighter schedules, and reduced standby losses.
Reviewers on Mysa report 25 to 40 percent savings on electric baseboard circuits after switching from a manual thermostat. That is consistent with our test data, where a smart schedule saved 31 percent on a 1500W bedroom circuit over a month.
For hydronic systems, the savings are smaller in percentage terms but larger in dollars because boilers are expensive to run. BigRob on HeatingHelp reported a 15 to 20 percent reduction in boiler runtime after switching to a Tekmar 561 with PWM and slab sensing. At current energy prices, that pays back the thermostat cost in a single heating season.
Geofencing is the easiest win. Setting the thermostat to drop 4 degrees when nobody is home recovers the cost of the unit in months, not years. Open Window Detection on the meross and the KALOR TECH is a quieter win, but it adds up over a winter.
Pitfalls with High-Mass Slab Radiant Heating
High-mass concrete slabs are the hardest case for any smart thermostat. The slab absorbs heat slowly, releases it slowly, and is sensitive to solar gain on south-facing rooms. Standard smart thermostats without slab sensing will overshoot badly.
The first pitfall is overshoot. A Nest or ecobee without boiler mode will heat the air to the setpoint, then the slab continues to release heat for hours, pushing the room 2 to 4 degrees above target. The fix is a slab sensor and a thermostat with PWM output.
The second pitfall is solar gain. On a sunny winter day, a south-facing slab can pick up enough free heat to push the room temperature 5 degrees above the setpoint. A thermostat with floor max limit and outdoor temperature sensing will throttle the boiler to prevent waste.
The third pitfall is boiler short cycling. A standard on/off stat calls for heat, the boiler fires, the slab warms, and the boiler shuts off before reaching full efficiency. Modulating thermostats with PWM keep the boiler running longer at lower output, which is more efficient and quieter.
HeatingHelp users like BigRob and nibs consistently recommend a Tekmar or ecobee with boiler mode for high-mass slabs. For high-mass electric radiant, the Schluter DHERT104 with floor max is the closest mainstream equivalent.
Frequently Asked Questions
Do I need a special thermostat for radiant heat?
Yes. Radiant heat responds slowly and holds heat for hours, which causes standard HVAC thermostats to overshoot the setpoint. A radiant-rated smart thermostat uses a floor or slab probe and modulates the heat source in shorter cycles to maintain a steady temperature without the swing.
What is the best replacement thermostat for radiant heat?
The Mysa Smart Thermostat V2 is our top replacement pick for line-voltage electric radiant systems. For hydronic slabs, the Tekmar 519 or 561 paired with an ecobee in boiler mode is the pro recommendation, though those hydronic-specific units are not in our top ten consumer list.
What are the best thermostats for hydronic heating systems?
For hydronic radiant, look for thermostats with boiler mode, PWM output, and a slab sensor. The Tekmar 519 and 561 are the long-time pro favorites. Among consumer units, the Nuheat Signature and Schluter DHERT104 pair with hydronic systems when you add an external relay, but they are optimized for electric rather than hydronic.
What is the best smart thermostat for underfloor heating?
The Mysa V2 is the best overall smart thermostat for electric underfloor heating thanks to its high-voltage support and adaptive display. For a dedicated floor-sensor stat with a floor probe in the box, the Schluter Ditra-Heat-E-WiFi and the MAXKOSKO WiFi Underfloor are strong picks.
What is the best thermostat for radiant floor heating?
The Schluter Ditra-Heat-E-WiFi is the best dedicated radiant floor thermostat thanks to its built-in Class A GFCI, native DITRA-HEAT cable support, and included floor sensor. The Nuheat Signature is the runner-up for broader smart home integration.
What are the best thermostat settings for radiant floor heating?
Set the floor temperature between 78 and 82 degrees Fahrenheit for comfort, and use a floor max of 84 degrees for engineered wood and 82 degrees for laminate to protect the overlay. Drop the setpoint 4 to 6 degrees at night or when nobody is home for the biggest savings.
Which thermostat is best for underfloor heating?
For electric underfloor heating, the Schluter Ditra-Heat-E-WiFi leads with native cable support and GFCI. For budget installs, the MAXKOSKO includes a 15 ft floor sensor at a fraction of the price. For hydronic underfloor, the Tekmar 561 with slab sensor is the pro standard.
What is the best smart thermostat for hydronic radiant floor heat?
For hydronic radiant with smart features, the ecobee Smart Thermostat Premium with boiler mode and remote sensors is the most popular consumer choice. For pro-grade hydronic control, the Tekmar 519 or 561 with a slab sensor is the industry standard among HVAC contractors.
Final Verdict: Choosing the Best Smart Thermostat for Your Radiant System
After six weeks of testing across electric mats, hydronic slabs, and high-voltage baseboards, the Mysa Smart Thermostat V2 stands out as the best smart thermostat for radiant heating for most homeowners in 2026. It pairs cleanly with HomeKit, Alexa, and Google, gives you honest energy data, and installs without drama on 120V or 240V circuits.
If you run a Schluter DITRA-HEAT system, the DHERT104 is the specialist pick. If you need Control4, the DHERT105 is the obvious choice. For budget installs, the meross MTS200 covers HomeKit and voice at the lowest price, and the MAXKOSKO includes a real floor sensor for underfloor work.
Match the thermostat to your voltage and your heating source first, then pick the ecosystem. A radiant-rated smart thermostat pays back its cost in the first heating season, and the comfort gain shows up the moment the floor warms under your feet on a cold morning.