Transform cold tiled floors into a consistently warm, comfortable surface with this complete electric underfloor heating bundle. It pairs a 150W/m² ThermoSphere Mesh heating mat — the most popular output for a primary heat source in well-insulated UK rooms — with the ENGO EONE-16W Wi-Fi smart thermostat and the ENGO EFS300 floor sensor for accurate overheat protection.
The self-adhesive TwistedTwin mesh mat installs wire-side-down directly onto the substrate, is IP68 rated for bathrooms and wet rooms, and can be tiled straight over without raising floor levels. The EONE-16W's built-in 16(2)A relay switches the mat directly with no external contactor on single-zone jobs, while its TPI control algorithm holds the set temperature tightly and its schedules keep running even if the home Wi-Fi drops out.
3 Years
Thermostat Warranty
🔴 Qualified Electrician Required
All electrical connections for the heating mat and the ENGO EONE-16W thermostat (switching mains voltage at up to 16(2)A) must be carried out by a qualified electrician in accordance with BS 7671. ENGO Controls accepts no responsibility for non-compliant installation.
🟡 Floor Sensor Recommended for Overheat Protection
The included ENGO EFS300 floor sensor connects to the S1/COM terminals on the EONE-16W and is strongly recommended whenever the thermostat is switching an electric heating mat, since it provides overheating protection that a room-only air sensor cannot. Set a maximum floor limit of around 27°C for tile and stone to stay within the mat manufacturer's recommendation.
🟢 150W/m² — The Most Popular Primary Heat Source Output
150W/m² is the most popular choice for a primary heat source in well-insulated UK domestic rooms. Cover at least 85% of the walkable floor area (excluding fixed furniture footprints) for even heat distribution. For conservatories or high heat-loss rooms, a 200W/m² mat is the better fit.
🟡 Going Above 3680W (16A) on a Single Circuit
The EONE-16W's internal relay is rated to 16(2)A — 3680W at 230V. Every size in this bundle's own range tops out at 12m² (1800W), so a single mat stays comfortably within that limit on its own. If this thermostat is later used to control a larger combined load — for example two mats on one circuit, or this mat plus another electric heating circuit — that exceeds 3680W, a suitably rated external contactor must be fitted. The EONE-16W's relay output then switches the contactor's low-current coil, while the contactor's heavier-rated contacts carry the full mat current. A qualified electrician should size the contactor to the total connected load.
TwistedTwin Cable — Stress-Free and Fully Earthed
ThermoSphere's proprietary TwistedTwin cable uses a twisted-pair conductor construction that neutralises mechanical stress, preventing the fractures that develop in conventional cables under repeated thermal cycling. A continuous full earth braid runs the entire cable length.
16A Relay Removes the Need for a Contactor
Most low-voltage thermostats top out at 3A and need a separate contactor to switch an electric mat. The EONE-16W's built-in 16(2)A relay handles the load directly, cutting a component and a wiring step out of straightforward single-zone jobs.
TPI Algorithm Holds Setpoint Tightly
The TPI (Time Proportional and Integral) control algorithm pulses the relay on and off in short bursts rather than simple on/off switching, keeping floor temperature closer to setpoint than a basic hysteresis thermostat allows.
Self-Adhesive, Wire-Side-Down Installation
The fully self-adhesive fibreglass mesh sticks wire-side-down to the substrate, protecting the cable during tiling and holding the mat flat for self-levelling — no additional fixing tape needed.
Works Fully Offline as Well as via the App
Heating schedules are stored on the EONE-16W thermostat itself, so daily or weekly programmes keep running even if the home Wi-Fi or internet connection drops out. Wi-Fi is only needed for remote access and setup via the ENGO Smart app.
LayFlat 4mm Cold Tail
The mat's LayFlat cold tail is only 4mm thick — far thinner than conventional cold tails — making it straightforward to conceal within the tile adhesive layer without any raised ridge in the finished floor.
ThermoSphere Mesh 150W/m² Heating Mat
| Output |
150 W/m² |
| Voltage |
230V / 50Hz |
| Total Thickness |
3.5mm |
| Cable Type |
TwistedTwin — full earth braid, FEP and HR-PVC insulation |
| Cold Tail |
LayFlat, 4mm thick |
| Protection Rating |
IP68 — wet room safe |
| Recommended Max Floor Temperature |
27°C (set via thermostat) |
| Suitable Floor Finishes |
Tile and stone tiled directly over; wood/vinyl with self-levelling overlay |
| Area Range |
1.5 – 12.0 m² per mat |
| Country of Origin |
United Kingdom |
| Warranty |
Lifetime (online registration required) |
ENGO EONE-16W Wi-Fi Smart Thermostat
| Power Supply |
230V AC, 50Hz |
| Max. Switching Current |
16(2)A |
| Control Output |
SL, 230V AC |
| Setpoint Range |
5.0°C to 45.0°C |
| Display Accuracy |
±0.5°C |
| Control Algorithm |
TPI, or hysteresis (±0.2°C to ±2.0°C) |
| Connectivity |
Wi-Fi 2.4GHz, MODBUS RS-485 |
| Sensor Input |
S1-S2 — floor / air / occupancy sensor, NTC 10/12/15kΩ |
| App Platform |
ENGO Smart (powered by Tuya) |
| Dimensions |
90 x 90 x 37mm (13mm finished depth after flush mounting) |
| Mounting |
Flush-mounted, standard 60mm electrical box |
| Colour |
White |
| Compliance |
2014/53/EU, 2011/65/EU |
ENGO EFS300 Floor Temperature Sensor
| Sensor Type |
Passive NTC thermistor |
| Nominal Resistance |
10kΩ at 25°C |
| Measuring Range |
−10°C to 100°C |
| Cable Length |
3m, 2×0.5 mm² cross-section |
| Connection |
S1/COM sensor terminals on the EONE-16W |
| Power Supply |
None — passive sensor |
| EAN |
5905481996338 |
| Warranty |
5 years |
Available Sizes
| Mat Size |
Power Output |
Cable Length |
| 1 m² |
150 W |
2 m |
| 1.5 m² |
225 W |
3 m |
| 2 m² |
300 W |
4 m |
| 3 m² |
450 W |
6 m |
| 4 m² |
600 W |
8 m |
| 5 m² |
750 W |
10 m |
| 6 m² |
900 W |
12 m |
| 7 m² |
1050 W |
14 m |
| 8 m² |
1200 W |
16 m |
| 9 m² |
1350 W |
18 m |
| 10 m² |
1500 W |
20 m |
| 12 m² |
1800 W |
24 m |
What size mat do I need?
Measure your walkable floor area and select a mat that covers at least 85% of it, excluding the footprint of fixed furniture such as baths, toilets, and kitchen units. As a primary heat source at 150W/m², closer to full coverage gives the most even result.
Do I need the ENGO EFS300 floor sensor?
Yes — it is included in this bundle and should always be fitted. It connects to the S1/COM input on the EONE-16W and provides overheat protection for the mat, which a room-only sensor cannot do on its own.
Can the EONE-16W switch the heating mat directly, without a contactor?
In most cases, yes. The thermostat's internal relay is rated to 16(2)A, which covers the full 1–12m² range of this mat without needing an external contactor.
Will the thermostat keep working if my Wi-Fi goes down?
Yes. Time schedules are stored locally on the EONE-16W and continue to run in offline mode. Wi-Fi is only required for remote control and initial setup through the ENGO Smart app.
Can I install this in a bathroom or wet room?
Yes — the ThermoSphere mat is IP68 rated, making it safe for wet rooms, bathrooms, and shower areas when installed with appropriate waterproofing accessories.
Who can install this bundle?
The heating mat and the mains-voltage EONE-16W thermostat must be connected by a qualified electrician in accordance with BS 7671. The mat itself can be laid by a competent DIY installer or tiler ahead of the electrical connection.
What do I do if my total load goes above 3680W (16A)?
The EONE-16W's built-in relay is rated to 16(2)A — 3680W. Every mat size in this bundle's range (up to 12m² / 1800W) sits well within that on its own. If the thermostat needs to control a combined load above 3680W — for example two mats wired to one thermostat, or this mat plus another electric heating circuit — fit a suitably rated external contactor. The thermostat's relay then switches the contactor's coil rather than the mat directly, and the contactor's own contacts carry the full load current. This is standard practice for any electric UFH thermostat once 16A is exceeded, and should be sized and fitted by a qualified electrician.
