RT-X1 Ascent Programmable Room Thermostat
The Legom RT-X1 Ascent Programmable Digital Thermostat is a 7-day programmable room thermostat for water-based underfloor heating and electric heating systems. With a large, clear backlit screen and positive-action traditional push buttons, the RT-X1 can be used as a simple temperature controller or as a full time-and-temperature programmer for improved energy efficiency. The classic styling, clearly labelled buttons, and slim 14mm panel profile make it easy to read and operate on any wall.
Built on a 230V AC supply with a high 16A switching capacity, the RT-X1 drives up to 3680W of load, making it suitable for both hydronic (wet) underfloor heating and electric heating circuits. It supports NTC 10k internal and external floor sensor configurations, draws under 1W in operation, and adds a child lock, holiday mode, and configurable low and high temperature protection to the standard Legom thermostat feature set. Manufactured by Legom in a White 86 × 86mm panel.
Key Benefits
- 7-day (5+2) weekly programming. Set up to six independent time and temperature periods per day, with a separate weekday and weekend schedule, so the heating matches the way the room is actually used and avoids heating empty spaces
- High 16A switching capacity. Switches up to 3680W of load, allowing the RT-X1 to control both hydronic underfloor heating valves and electric heating circuits from a single thermostat
- Traditional push-button operation. Positive, ergonomic physical buttons give clear tactile feedback and reliable operation, with no touch-sensitivity issues in cold or humid rooms
- Slim-line styling. A 14mm slim front panel sits close to the wall for a clean, modern-classic finish
- Internal and external sensor modes. Operate from the built-in sensor, an external floor probe, or both together, where the internal sensor controls room temperature and the external probe limits floor temperature
- Child lock function. Press and hold Up and Down together for 5 seconds to lock the keypad and prevent unauthorised temperature changes
- Holiday and energy-saving modes. Hold a steady low temperature during extended absences to save energy while protecting the room from frost
- Low and high temperature protection. Configurable protection thresholds guard the floor and the room against overheating and freezing
- Ultra-low power consumption. Draws less than 1W in normal operation
- Accurate control. Maintains the setpoint to within ±1°C using an NTC 10k, 1% sensor
Technical Specifications
| Parameter | Specification |
|---|---|
| Model | RT-X1 |
| Operating Voltage | 230V AC ~ 50Hz |
| Power Consumption | < 1W |
| Max Load Current | 16A |
| Max Load | 3680W (suitable for hydronic or electric heating) |
| Temperature Sensor | NTC 10k, 1% |
| Working Temperature Range | 5°C ~ 45°C |
| Control Accuracy | ± 1°C |
| Programming | 7-day (5+2), six periods per day |
| Dimensions | 86 × 86 × 39.5mm |
| Panel Profile | 14mm slim-line front |
| Mounting | In-wall (35mm minimum box depth) |
| Protection Rating | IP20 |
| Colour | White |
Operation Buttons
| Button | Function |
|---|---|
| Power | Short press to turn the thermostat on or off |
| M | Short press to switch between programming mode and manual mode |
| Clock | Short press to set the time and weekday. Long press to enter programming |
| Up | Increase the temperature or setting value |
| Down | Decrease the temperature or setting value |
| Key Lock | In the powered-on state, press and hold Up and Down together for 5 seconds to lock or unlock the keypad |
Default Weekday Schedule (5+2)
| Period | Event | Start Time | Target Temp |
|---|---|---|---|
| 1 | Wake up | 06:00 | 20°C |
| 2 | Leave home | 08:00 | 15°C |
| 3 | Back home | 11:30 | 18°C |
| 4 | Leave home | 13:30 | 15°C |
| 5 | Back home | 17:00 | 20°C |
| 6 | Sleep | 22:00 | 18°C |
The recommended comfort range is 18°C to 22°C. Each period runs until one minute before the next period begins.
Display Indicators
| Indicator | Meaning |
|---|---|
| Heat symbol | Calling for heat (output active) |
| Hand symbol | Manual mode |
| Clock symbol | Time programming mode |
| Hand and clock together | Temporary manual override (ends when the next programmed period starts) |
| Lock symbol | Button lock active |
Terminal Functions
| Terminal | Function |
|---|---|
| N | Neutral (power supply input, Blue) |
| L | Live (power supply input, Brown) |
| LOAD | Switched live output to the heating valve, actuator, or contactor (16A max, SWL Brown) |
| 5 / 6 | NTC external floor sensor (10k, optional) |
Advanced Settings Parameters
| Item | Function | Default | Range |
|---|---|---|---|
| 1 | Temperature compensation | -2°C | -9°C ~ +9°C |
| 2 | Start-up temperature difference | 1°C | 1°C ~ 5°C |
| 3 | Sensor type | In | In: built-in / OU: external / AL: internal + external |
| 4 | Low temperature protection | Off | 5°C ~ 10°C or off (turns on heat during shutdown if the room drops below the set value) |
| 5 | High temperature protection | 50°C | 25°C ~ 50°C or off (external sensor only) |
| 6 | Key lock scope | 0 | 0: lock all keys except power / 1: lock all keys including power |
| 7 | Programming type | 01 | 01: 5+2 / 02: 6+1 / -: non-programmable |
| 8 | Backlight | 0 | 0: auto off after 10s / 1: always on |
| 9 | Temperature upper limit | 45°C | 5°C ~ 99°C |
| 10 | Restart after power failure | 2 | 0: stay on / 1: stay off / 2: restore previous state |
Error Codes
| Code | Meaning and Action |
|---|---|
| E1 | Internal sensor short circuit. Check the internal sensor pins for a short |
| E2 | Internal sensor open circuit. Check the internal sensor pins for a disconnection |
| No display | Power input error or a loose connector between the panel and the power board. Check the supply voltage and cabling, then re-seat the board |
| Abnormal reading | Adjust the temperature compensation value (advanced item 1) |
Application & Use Cases
- Hydronic underfloor heating. The primary application. The RT-X1 schedules and controls water-based underfloor heating zones through a thermal actuator or valve, holding each room at its programmed temperature throughout the week
- Electric heating circuits. The 16A switching capacity and 3680W load rating allow the RT-X1 to drive electric heating directly or through a contactor, making one thermostat suitable across mixed installations
- Energy-conscious homes and offices. The 5+2 schedule with six daily periods lets occupants warm rooms only when they are in use, reducing energy waste during work hours and overnight
- Holiday homes and seasonal properties. Holiday mode and the low temperature protection function keep a property frost-protected during extended absences without leaving the heating running at full setpoint
- Installations requiring child-proof controls. The child lock makes the RT-X1 appropriate for nurseries, classrooms, hotel rooms, and rental units where unauthorised temperature changes must be prevented
- Floor-limited installations. The external NTC probe and high temperature protection allow the RT-X1 to control room comfort while capping floor surface temperature on engineered wood or sensitive finishes
Installation Notes
- Install at approximately 1.4 metres above floor level, away from direct sunlight, drafts, and heat sources, in a 35mm minimum depth wall box
- Installation must be carried out by a qualified electrician in accordance with BS7671 / IET wiring regulations
- Provide an all-pole disconnection with at least 3mm contact separation in the fixed wiring, and fit an RCD where required. Earth the metal back box
- To open the unit, slide the front housing upwards from the slots on the back plate, then disconnect the ribbon cable if needed and set the front housing aside
- Make the wiring connections per the terminal diagram: Neutral (Blue) to N, Live (Brown) to L, switched live (Brown) to LOAD, and the external NTC sensor to terminals 5 and 6
- Screw the back plate to the wall box through the fixing holes
- Reconnect the ribbon cable, then refit the front housing by sliding it downwards into the rear housing slots
- Do not exceed the 16A maximum load current
- Child lock: in the powered-on state, press and hold Up and Down together for 5 seconds to activate or deactivate
- Enter programming: with the unit powered on, press and hold the Clock button for 5 seconds
- Factory reset: with the unit powered on, press and hold two keys together for 5 seconds. The full screen shows for one second and then powers off, confirming the reset
Frequently Asked Questions
Is the RT-X1 suitable for both hydronic underfloor heating and electric heating?
Yes. The RT-X1 has a 16A switching capacity and a 3680W maximum load, so it can control water-based underfloor heating through a thermal actuator or valve, and it can also drive electric heating circuits directly or through a contactor. This makes a single thermostat model suitable across mixed heating installations. Always confirm that the connected load does not exceed 16A.
How many time and temperature periods can I program each day?
The RT-X1 supports six time periods per day on a 5+2 weekly schedule, which applies one program to the five weekdays and a separate program to the two weekend days. Each period has its own start time and target temperature, so the heating can step up and down through the day to match wake, away, and sleep patterns. The programming type can also be switched to 6+1 in the advanced settings.
What is the difference between the internal sensor and external floor sensor modes?
The RT-X1 supports three sensor configurations set in advanced item 3. In In mode it controls from the built-in room sensor. In OU mode it controls from the external floor probe. In AL mode it uses both, where the internal sensor controls room comfort and the external probe limits the floor temperature. AL mode with high temperature protection is recommended for engineered wood and other temperature-sensitive floor finishes.
How do I activate the child lock?
In the powered-on state, press and hold the Up and Down buttons together for 5 seconds. The lock icon appears on the display, confirming that the keypad is locked. Repeat the same action to unlock. By default the power key remains active under the lock, but advanced item 6 can be set to lock all keys including power.
Does the RT-X1 remember its settings after a power cut?
Yes. The weekly program and configuration are retained in memory. The behaviour after power is restored is set by advanced item 10: by default (value 2) the thermostat restores the state it was in before the interruption. It can also be set to always power on (0) or always stay off (1) after a power failure, which is useful in rental and commercial installations.
What does a temporary manual override do?
While running a program, you can adjust the temperature with the Up or Down buttons to set a temporary override. The hand and clock indicator appears, and the override holds until the next programmed period begins, at which point the thermostat returns to its schedule automatically. This lets you change the temperature for a few hours without editing the weekly program.
OEM & ODM Customization
Legom supports OEM and ODM services for the RT-X1 Ascent Thermostat series. Housing color, branding, default schedule, and configuration parameters can be customized for distributor and system integrator requirements. All customization projects are handled with strict confidentiality. Contact us via WhatsApp or info@legomsmart.com.
User Manual
Product information last reviewed by the Legom Technical Team. For the most current specifications, refer to the official datasheet or contact our sales team.
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Legom is a direct manufacturer offering end-to-end OEM and ODM services. With our in-house engineering and production capabilities, we work closely with distributors and system integrators to deliver fully customized solutions under strict NDA.
