terneo smart thermostat SX

Introduction

The Smart thermostat terneo SX is designed to control a warm floor based on an electrical heating cable, a heating film, or in a warm water floor system. It can be controlled via the terneo mobile app, the my.terneo web-page, or by voice via Google Assistant.

The device can also control underfloor water heating using an electro-thermal servo actuator with a 230 V operating voltage. For infrared panels, electric convectors, and other electric heaters, heating is controlled based on an air temperature sensor.

QR codes for downloading the terneo mobile app for iOS and Android are available on the first page.

Supply Package

• Thermostat, frame: 1 piece
• Temperature sensor with connected sensor: 1 piece
• Warranty certificate and card, technical passport, installation instructions: 1 piece
• The packing box: 1 piece

Scan the QR code to see all the benefits of the Smart thermostat terneo SX and download the terneo app features brochure.

IMPORTANT: Before installation and operation, read this document carefully to avoid potential dangers, mistakes, and misunderstandings.

In case of no voltage, all thermostat and heating schedule settings are kept in the non-volatile thermostat storage, and the clock will continue to operate powered by the internal power source for three days.

Technical Data

Wiring

The thermostat supports two types of sensors: analog sensor (thermal resistor) or digital sensor (DS18B20).

Analog sensor (R10): Connect to terminals 1 and 2. Wire colors are not important.

Digital sensor (D18): Connect to terminal 1 using the white wire and to terminal 2 using the blue wire. If the thermostat enters an accidental offloading regime by timer, try swapping the wires (blue to terminal 1, white to terminal 2). If neither attempt works, contact the Service Center.

Power voltage (230 V ±10%, 50 Hz) is supplied to terminals 4 and 5. The phase (L) is indicated by an indicator and connects to terminal 5; neutral (N) connects to terminal 4.

Load (heating element wires) connects to terminals 3 and 6.

Wiring Diagram 1: Connection of the Circuit Breaker and SSD

This diagram illustrates the connection of a circuit breaker (CB) and a Safety Shutdown Device (SSD) in the phase conductor before the thermostat. The CB should be rated for no more than 16 A. The SSD is obligatory for floor heating in wet areas to protect against electric shock.

Wiring Diagram 2: Simplified Internal Circuit

This diagram shows the internal circuit of the thermostat, including connections for phase (L), neutral (N), load, and sensor. It also depicts the mounting box and the optional contactor for loads exceeding 2/3 of the maximum specified power.

Installation

The thermostat is designed for indoor installation. Minimize the risk of moisture or liquid ingress. When installed in bathrooms, toilets, kitchens, or swimming pools, place it out of reach of casual spraying. The ambient temperature during installation must be between -5 °C and +45 °C. The installation height should be between 0.4 m and 1.7 m above the floor level.

To protect against short-circuits in the load circuit, install a circuit breaker (CB) rated for not more than 16 A in the phase conductor before the thermostat, as shown in Wiring 1.

To protect against electric shock, install a Safety Shutdown Device (SSD). This is mandatory for floor heating in wet areas.

The thermostat mounts in a standard 60 mm diameter mounting box using screws. Installation steps include:

• Make a hole in the wall for the mounting box and a chase for power wires and the sensor.
• Run power wires and the sensor wire to the mounting box.
• Perform connections according to the technical passport.
• Remove the front frame, place the thermostat in the mounting box, and tighten the mounting screws.

Thermostat terminals accept wires up to 2.5 mm². Using soft wire is recommended to reduce mechanical load. Wire ends must be cleaned and crimped with insulation ferrules. Tighten terminals with a screwdriver (blade width no more than 3 mm) to a torque of 0.5 N·m. A wider blade can damage terminals and void the warranty.

A mounting tube (metal, Ø 16 mm) should extend about 0.5 m into the heated zone from the mounting box. Ensure smooth sensor movement. Seal the end of the tube to prevent ingress of screed. Insert the sensor after the screed solidifies.

Sensor connecting wires can be extended or reduced (up to 20 m). Keep power cables away from sensor wires to prevent interference.

The thermostat should switch current not exceeding 2/3 of the maximum power specified. If the load exceeds this, connect the heating cable via a contactor (magnetic starter, power relay) designed for that current (see Wiring 3, not shown in detail but implied).

Warranty Terms

The warranty for terneo devices is valid for 36 months from the date of sale, provided instructions are followed. For products without a warranty certificate, the period starts from the date of production.

If the device malfunctions, first consult the "Possible Problems" section. If an answer is not found, contact the Service Center. Most issues can be resolved this way.

If problems persist, send the device to a Service Center or the store of purchase. Defective devices will be repaired or replaced within 14 business days.

Full warranty text and required data for the Service Center are available on the website (found in the Contacts section).

Guarantee Card details: Serial No., Seller, Seal, Owner Contact, Date of Sale, Place of Seal.

Service Center Contact: +38 (091) 481-91-81 (WhatsApp, Viber, Telegram), support@dse.com.ua

Smart Remote Control Features

• WLAN control from a mobile app
• Weekly schedule
• Energy consumption graphs (kWh and monetary terms)
• "Nobody is home" and Preheat functions (self-learning)
• Single control over a group of thermostats
• Granting access to other family members
• Voice control via Google Assistant

Smart functions can save up to 50% by maintaining a comfortable floor temperature only when needed.

Connecting to the Cloud for Control Features

The "cloud" service securely stores data online, enabling comfortable and safe long-distance connection and operation. With an internet connection, the thermostat synchronizes with the cloud, executes commands, receives settings, and sends status telemetry. If remote control is blocked, the cloud only accumulates statistical data.

For correct statistics and heating schedules, specify your time zone after connecting to the cloud. The thermostat will then independently update the date and time online.

In the absence of the internet, the thermostat continues operation based on the latest settings. Control is still possible via thermostat buttons or offline mode in the terneo app. Mobile data can be used via a WLAN Hotspot from another device (e.g., smartphone).

When Wi-Fi connection is restored, all settings synchronize. Not recommended for networks with Multi WAN technology.

If previously connected, choose "CLi" (Client mode). If connecting for the first time or changing settings, refer to the app instructions.

Connection using the App

Android App

1. Download and launch the free terneo app from Google Play.
2. Register or log in using your Facebook, Apple ID, or Google account.
3. Set the thermostat to "AP" (Access Point) mode. It stays in this mode for approximately 10 minutes. If no connection is made, it returns to "CLi" (Client mode). To switch to AP mode: press the "=" button until "APC" appears, then use "+" or "-" to change "CLi" to "AP".
4. When in AP mode, the screen displays "con" (connection) every 5 seconds.
5. In the app, press "+", then "Device" or "=", then "Add th", then "Device".
6. Select the Wi-Fi network created by the thermostat (e.g., terneo sx_A68FDB).
7. Enter your Wi-Fi name and password. (5G networks are not supported).

Follow the app's instructions. With internet access, the thermostat will be added to the main screen and registered in the cloud.

iOS App

1. Download and launch the free terneo app from Google Play.
2. Register or log in using your Facebook, Apple ID, or Google account.
3. Set the thermostat to "AP" (Access Point) mode. It stays in this mode for approximately 10 minutes. If no connection is made, it returns to "CLi" (Client mode). To switch to AP mode: press the "=" button until "APC" appears, then use "+" or "-" to change "CLi" to "AP".
4. When in AP mode, the screen displays "con" (connection) every 5 seconds.
5. In the app, press "+", then "Device" or "=", then "Add th", then "Device".
6. Select the Wi-Fi network created by the thermostat and press "Further". (5G networks are not supported).
7. On your iPhone, go to WLAN settings and connect to the thermostat's Wi-Fi network (e.g., terneo x_A68FDB). If a password is required, enter DSEXXXXXX (where XXXXXX are the last six symbols of the network name, e.g., DSEA68FDB).

Return to the app and follow the instructions. With internet access, the thermostat will be added to the main screen and registered in the cloud.

Connection through Web Page my.terneo

1. Set the thermostat to "AP" (Access Point) mode. It stays in this mode for approximately 10 minutes. If no connection is made, it returns to "CLi" (Client mode). To switch to AP mode: press the "=" button until "APC" appears, then use "+" or "-" to change "CLi" to "AP".
2. When in AP mode, the screen displays "con" (connection) every 5 seconds.
3. On your desktop, go to WLAN settings and connect to the thermostat's Wi-Fi network (e.g., terneo sx_A68FDB). If a password is required, enter DSEXXXXXX (where XXXXXX are the last six symbols of the network name, e.g., DSEA68FDB). Android may prompt to confirm connection to a WLAN network without internet access; click "Do not disconnect" to continue.
4. In your browser's address bar, type 192.168.0.1.
5. On the thermostat page, select your Wi-Fi network and enter its password. Click "Connect".
6. The thermostat will establish a connection to your Wi-Fi network within one minute. A constant blue indicator light signifies a successful connection.
7. After connection, the thermostat screen displays a PIN code (three digits) for cloud connection.
8. On your phone, ensure you are connected to your home WLAN network.
9. In your browser's address bar, enter my.terneo.
10. Register or log in using your Facebook, Apple ID, or Google account.
11. In the desktop app, click "+ Add" -> "Device", enter a name (e.g., "Bedroom"), and the PIN code displayed on the thermostat screen. Press "Next" to add the device.

* If no PIN-code is displayed, refer to the "PIN-code for registration in the cloud or local IP" section in Table 1. If "iP" is displayed instead of a PIN, it indicates no connection with the cloud. If neither "Pin" nor "iP" is displayed, the WLAN connection has failed.

To change your Wi-Fi password, follow the first six points of the "Connection through web page my.terneo" section.

Status of the Blue Indicator

Control from Buttons

After switching on, the thermostat displays the sensor temperature. If it's below the set temperature, voltage is applied to the load, and the indicator glows red.

Use "+" or "-" buttons to change the heating temperature. The screen will first show the operating mode, then the set temperature for that mode.

To view menu sections, press the "=" button multiple times. Use "+" and "-" for selection and changes. After 5 seconds of inactivity, the display returns to temperature view.

Function Menu

Button Features

Button AutoLock (Protection Against False Button Tapping)

Activates 20 seconds after the last button tap when "Button blocking" is off. To unlock, consistently tap 3 buttons from left to right. The screen will display 3 dashes during the process.

Button Blocking (Child and Public Protection)

To enable/disable, press "+" and "-" buttons simultaneously for 6 seconds until "Loc" or "unLoc" appears.

Factory Reset

To reset all settings (except Wi-Fi) to factory defaults, press and hold the "-" button for 30 seconds until "dEF" appears. The thermostat will reload.

Viewing Firmware Version

Hold the "-" button for 12 seconds to display the firmware version (e.g., F2.5). The thermostat returns to normal mode after release. If the version differs from the manual, download the appropriate Operation Manual from the website.

DS Electronics reserves the right to make changes to firmware, cloud interface, and applications for device optimization.

Enabling Sleep Mode

Hold the "=" button for 4 seconds (3 dashes appear sequentially) until "OFF" is displayed. For complete shutdown, turn off the circuit breaker. To disable sleep mode, hold the middle button for 4 seconds until "on" appears.

Possible Problems, Causes, and Ways to Overcome Them

Load does not operate (screen displays "OC" or "SC" every 5 seconds)

Cause: "OC" - open circuit of the sensor; "SC" - short circuit of the sensor.

Solution: Check sensor circuit connection, look for damage on the wire, and ensure no power wiring passes nearby.

Thermostat switched to Emergency Timer Mode

Cause: Failed connection, sensor circuit damage, or temperature out of range. This mode ensures heating operation if the sensor is damaged.

Solution: Check sensor connection and wiring. Ensure mechanical integrity. The mode allows setting heating time (1-29 min) or continuous operation ("on") or off ("OFF").

Indicator/Display not lighting up upon thermostat switch-on

Cause: No power supply voltage.

Solution: Check power supply voltage with a voltmeter. If voltage is present, contact the Service Center.

Thermostat not responding to app changes

Cause: Blocking of changes from the cloud is enabled.

Solution: Go to the thermostat menu section "bLc" and change its status to "OFF" (see Table 1, "Remote management blocking by thermostat").

Load is disabled (screen displays "oHT" flashing)

Cause: Internal overheating (temperature inside housing exceeded 90 °C). This can be due to bad terminal contacts, high ambient temperature, overwhelming power output, or incorrect wire cross-section.

Solution: Check power wire tension in terminals. Ensure switching load does not exceed permissible limits and wire cross-section is correct. The device unlocks when internal temperature drops to 71 °C. If protection trips more than 5 times in 24 hours, it locks until temperature drops to 63 °C and a button is pressed, or after 30 minutes of inactivity. Pressing any button during overheat displays the thermal protection sensor temperature.

Internal overheating sensor error (screen displays "Ert" flashing)

Cause: Open or short circuit of the internal overheating sensor.

Solution: Send the device to the Service Center. Control over internal overheating will not be performed.

Internal power supply issue (screen displays "Lbt" flashing)

Cause: Discharge or damage to the internal power supply.

Solution: Wait approximately 1-2 hours to charge the power supply or contact the service center. If there is no power in the network, the clock will not continue operating.

Controller offline (LED stopped glowing blue)

Cause: Internet connection unavailable, provider issues, router change/damage, or router settings issues.

Solution: Ensure available WLAN connection or internet access. If router settings changed, reconnect thermostat via terneo desktop app. Temporarily control temperature using thermostat buttons or offline mode in the Android app.

Thermostat does not display PIN code (blue indicator constantly on)

Solution: Go to the "Pin" section on the thermostat (see Table 1) to view the PIN code.

Connection failed via apps (blue indicator is on)

Cause: Thermostat connected to the cloud, but the account is not accessed.

Solution: Follow steps 8-10 for connecting via the my.terneo desktop application.

Preliminary warming up issues (incorrect operation)

Cause: "Preliminary warming up" function disabled in the app; frequent temperature changes or insufficient heating power; transition between heating/cooling modes completed too soon; floor temperature offset changed too recently.

Solution: Ensure stable room temperature, sufficient heating power, adequate time for self-learning after mode transitions or offset changes. Verify "Preheat" function is enabled in the app, thermostat is in schedule mode, and enough time has passed for self-learning.

Heating does not turn off / set heating temperature not reached

Cause: Insufficient heating cable power; lack of thermal insulation; incorrect installation of heating cable or sensor; insufficient power supply network capacity.

Solution: Verify correct installation of heating cable and sensor, adequate thermal insulation, and sufficient power supply capacity. Contact the service center if issues persist.

Screen displays a flashing dash when a button is pressed

Cause: Buttons AutoLock is active.

Solution: To unlock, consistently tap 3 buttons from left to right. The screen will display 3 dashes.

Wrong password when connecting to the thermostat's Wi-Fi network

Solution: Enter the password case-sensitive, language-sensitive, and number-of-character-sensitive. The password is typically the last six symbols of the network name (e.g., DSE68FDB).

Additional Information

Do not dispose of the device with household waste. After its service life, the product must be disposed of according to applicable law.

The device is transported by any type of transport, ensuring package safety.

Date of manufacture is on the back of the device. Application time is unlimited. The device does not contain harmful substances.

For any questions, call the Service Center.

Safety Instructions

• Carefully read and understand these instructions.
• Connection must be done by a qualified electrician.
• Do not connect 230 V mains voltage instead of the sensor, as it leads to thermostat failure.
• Before installation/dismantling and connection/disconnection, turn off the voltage supply and follow "Rules of arrangement of electric installations".
• Do not immerse the sensor with its connecting wire in liquid.
• Do not switch on the non-assembled device.
• Turn on/off and configure the device with dry hands.
• Do not connect the device to the network disassembled.
• Avoid contact with water or moisture.
• Do not expose the device to extreme temperatures (above 40 °C or below -5 °C) and high humidity.
• Never clean the device with chemicals like benzene or solvents.
• Do not store or use the device in dusty areas.
• Do not attempt to disassemble or repair the device.
• Do not exceed the specified adaptor and power limits.
• Use a lightning protector against overvoltage caused by lightning discharges.
• Protect children from playing with the working device, as it is dangerous.

Manufacturer Information

Manufacturer and vendor: DS ELECTRONICS, LTD

Address: 04136, Ukraine, Kyiv region, Kyiv, 1-3 Pivnichno-Syretska str.

Phone: +38 (091) 481-91-81

Service Center: +38 (091) 481-91-81

Email: support@dse.com.ua

Website: www.ds-electronics.com.ua/en/

Certifications: Low Voltage Directive 2014/35/EU, EMC Directive 2014/30/EU. CE mark is present.