LuxHeat 40sqft Electric Radiant Floor Heating System - 120v Underfloor Heating System - Includes UDG4 Programmable Thermostat w/GFCI, Heat Cable, Uncoupling Membrane for Under Tile, Sensor & Alarm

Why I chose this kit

I’ve installed a handful of radiant floor systems over the years, from prefab mats to hydronic loops. For a recent bathroom project, I wanted three things: design flexibility, a reliable thermostat with safety built in, and an underlayment that would protect tile from movement and moisture. The LuxHeat 40‑sq‑ft radiant floor kit checked all those boxes on paper, so I put it to work under a porcelain tile floor in a 6' x 8' bathroom.

What’s in the box

The kit is thoughtfully bundled. You get:
- A 120V, 160‑ft dual‑conductor heat cable rated 480 W (about 12 W/sq‑ft at 3" spacing)
- A Prova Flex‑Heat uncoupling/waterproofing membrane (50 sq‑ft, 6.5 mm thick)
- An OJ Microline UDG4 touchscreen thermostat with integrated Class A GFCI and floor sensor
- A continuity/alarm tester and the usual install accessories, including a wood float

Build quality is solid. The cable has an aluminum shield and a robust cold‑lead connection, and the membrane is dense, consistent, and easy to cut cleanly. The thermostat feels premium without being fussy, and the GFCI integration eliminates the need for a separate GFCI breaker in many scenarios (check local code).

Note: the box is heavy and bulky. If you’re hauling up stairs solo, plan accordingly.

Planning the layout

Planning is where these cable‑and‑membrane systems shine compared to fixed mats. The Prova membrane’s stud pattern makes it easy to route the cable in straight runs and U‑turns. The 40‑sq‑ft heat coverage (at 3" spacing) is generous for a small bath, and the kit includes 50‑sq‑ft of membrane so you can carry the uncoupling/waterproofing across areas you’re not heating (under the vanity, for example).

A few practical tips from my install:
- Dry‑fit the membrane and sketch a routing plan before mixing thinset. The cable cannot be cut or shortened, so you need a loop layout that “uses up” the length without crowding or crossing.
- Avoid running cable under permanent fixtures or within a couple inches of walls and floor penetrations.
- Place the floor sensor midway between two runs of cable, about 12" into the heated area, and avoid putting it near an exterior wall, sunny windows, or supply vents.

I checked cable resistance with a multimeter before, during, and after installation. The included alarm is useful—it screams if you nick the cable—but I still like to log resistance values during each step.

Installation experience

• Subfloor and membrane: I set the membrane into fresh modified thinset (appropriate for plywood substrate) using the included wood float to fully bed it. It bonds well, but you do need to work methodically to avoid voids. The 6.5 mm thickness adds a noticeable build to the floor, so plan your transitions. For wet areas, I sealed seams and edges with a compatible waterproofing band and thinset.

• Routing the cable: The heat wire presses into the membrane studs with a firm thumb push. It stays put, even around tight returns. I ran 3" spacing in open areas and adjusted spacing slightly at the edges to land cleanly without compressing loops. The cold lead routed in a shallow notch up to the thermostat box.

• Covering the wire: You can tile directly by filling over the cable with thinset as you set the tiles, but I prefer pouring a skim of self‑leveling underlayment over the membrane/cable to create a perfectly flat surface. It speeds up tile work and improves coverage over the wires. Either way, the cable must be fully embedded—no air pockets.

• Electrical and thermostat: The UDG4 thermostat is 120V, 15A, with integrated GFCI and dual sensing (air/floor). Wiring is straightforward, though the diagram in the manual is a bit terse. I mounted it in a standard single‑gang box with a separate conduit for the sensor lead and verified ground fault protection on power‑up. If you’re new to this, budget time to read the manual and check local code; a dedicated circuit may be required.

From unboxing to tile ready, the install took a day and a half, not counting cure times for the self‑leveler and tile.

Performance and controls

Warm‑up is predictable. In my space (porcelain tile over self‑leveler, on a wood subfloor), the surface temperature rose about 8–10°F in the first 30 minutes and reached a comfortable setpoint within 60–75 minutes. After that, the system sips power, cycling to maintain temperature.

Heat distribution is even, with no detectable striping. The dual‑conductor cable, aluminum shielding, and low‑EMF design are reassuring from a safety standpoint, and the wet‑location listing makes it appropriate for bathrooms. No hum, no hot spots, no nuisance trips from the GFCI in my use.

The thermostat is a strong point:
- 7‑day scheduling with four events per day lets me pre‑warm the floor before morning showers and dial it back when the room is not in use.
- The adaptive/self‑learning mode did a good job predicting warm‑up times after a few cycles.
- Power logging gives a basic look at consumption; max draw is 480 W, and in practice the duty cycle averages 20–50% depending on setpoint and room conditions.
- Child lock and simple touch UI make it easy to live with.

On energy use: at full draw it’s like running five LED shop lights. In shoulder seasons when the system runs more, I measured roughly 0.3–0.6 kWh per day for a programmed two‑hour morning warmup—a very manageable cost for the comfort it provides.

What I liked

• Flexibility: The cable‑in‑membrane approach lets you heat the areas that matter and avoid obstacles without fighting a fixed mat. Layout changes are painless on the fly.
• Tile underlayment: The Prova membrane isn’t just a cable holder; it’s a legitimate uncoupling, load‑support, and waterproofing layer. That’s real value in a tile assembly.
• Safety and approvals: cULus listing, Class A GFCI, wet‑location rating, and very low EMF are exactly what I want in a bathroom install.
• Thoughtful kit: Floor sensor, continuity alarm, a solid thermostat, and enough membrane to extend beyond heated zones—it’s all there.
• Warranties: Long warranties (25‑year on the cable, 50‑year on the membrane) suggest the manufacturers expect these components to last.

Where it could be better

• Documentation: The thermostat wiring/diagram could be clearer for first‑time installers. The essentials are there, but a more visual step‑through would reduce second‑guessing.
• Bulk and height: The box is heavy, and the membrane adds 6.5 mm before thinset/tile, which affects door clearances and transitions.
• No forgiveness on cable length: As with any resistive cable, you cannot cut it. If your layout changes late, you have to re‑route to consume the length, which takes planning.
• Requires full embed: Skipping a self‑leveler can make tile setting slower if you’re not comfortable floating over wires. Not a flaw, but something to plan for.

Suitability and use cases

This kit is at its best under ceramic or porcelain tile in bathrooms, powder rooms, mudrooms, and kitchens where comfort and crack isolation matter. It’s an excellent secondary heat source and can offset chill in basements, but I wouldn’t spec it as sole heat in poorly insulated spaces. It’s not intended for vinyl or engineered wood without a proper assembly—stick to tile over thinset/self‑leveler and follow the manufacturer’s floor covering guidance.

If you’re a DIYer comfortable with tile work and basic electrical, this is approachable. If wiring isn’t your lane, have an electrician make the final connections and test the GFCI.

Bottom line

The LuxHeat 40‑sq‑ft kit pairs a flexible, low‑EMF heat cable with a high‑quality uncoupling membrane and a capable, safety‑focused thermostat. Installation is straightforward if you plan your layout and embed the cable correctly, and the end result is a warm, even, and responsive floor assembly that also does right by your tile.

Recommendation: I recommend this kit for small to mid‑size tile installations where you want both radiant comfort and a robust substrate in one package. The overall value is strong, the components are well made, and the system performs as promised. Be mindful of floor height and take your time with layout and embedding; do that, and you’ll end up with a reliable heated floor that feels far more “custom build” than its price suggests.