> For the complete documentation index, see [llms.txt](https://wiki.inels.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://wiki.inels.com/inels-home/inels-wireless/devices/inels-wireless-heating-temperature-control/thermostats/rftc-4.md).

# RFTC-4

RFTC-4 — battery-powered glass touch thermostat in black or white. Controls switch units for heating and fan coils, with Wi-Fi web configuration.

*Part 3 — Unit reference · Heating and temperature control.*

The **RFTC-4** is a smart glass thermostat that runs on **two AA batteries** or on USB-C power. It has a touch display and eight backlit touch buttons. It measures temperature and humidity in the room and tells **switch units** to heat or cool. It talks to them by radio (iNELS RFIO2) and is set up through **Wi-Fi** in a web browser.

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![RFTC-4 white](https://2503278529-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FkoLW6hWCvDgagoswDVfD%2Fuploads%2FDYT9eumMKP8KkuYxLVeT%2Frftc-4-white.png?alt=media)
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![RFTC-4 black](https://2503278529-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FkoLW6hWCvDgagoswDVfD%2Fuploads%2F6ACP4lcxCmY6wShQKpYN%2Frftc-4-black.png?alt=media)
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{% hint style="info" %}
For the first set-up, the Wi-Fi connection, pairing and reset, follow the instruction supplied with the unit.
{% endhint %}

## At a glance

|            | RFTC-4/W (white) | RFTC-4/B (black) |
| ---------- | ---------------- | ---------------- |
| Order code | 8917             | 8916             |
| EAN        | 8595188189170    | 8595188189163    |

|                           |                                                                                        |
| ------------------------- | -------------------------------------------------------------------------------------- |
| Power                     | 2 × AA 1.5 V batteries **or** USB-C 5 V                                                |
| Wi-Fi                     | 2.4 GHz — **only with external power** (USB-C)                                         |
| Radio                     | iNELS RFIO2, 866–922 MHz                                                               |
| Display                   | LCD (VA/TN), active area 54 × 34 mm                                                    |
| Buttons                   | 8 capacitive, backlit, configurable                                                    |
| Built-in sensors          | Temperature 0 to +55 °C, accuracy ± 0.5 °C · Humidity 0–99 % RH, accuracy ± 3 %        |
| Mounting                  | EU or British installation box with 60 mm screw spacing, or the table stand            |
| In the package (pictured) | Table stand, 230 V / 5 V power adapter, base, top cover with display, 2 × AA batteries |

## What it controls

The RFTC-4 is designed to control:

| Unit             | What it is                                                                                |
| ---------------- | ----------------------------------------------------------------------------------------- |
| **RFSTI-11B-SL** | Switch unit with an external temperature sensor (for example electric underfloor heating) |
| **RFSA-66M**     | 6-channel switch unit (for example electric underfloor heating)                           |
| **RFSA-266M**    | Switch unit for fan coil control — heating and cooling                                    |

It can also use these units as inputs: **RFTI-20** temperature and humidity sensor, **RFWD-100** window detector, **RFMD-200** motion detector. The display shows a window / door icon when a window is open.

Two of the buttons can be set to control **switch units, dimmers or blind units** from the iNELS Wireless range.

## Power and Wi-Fi

* **On batteries** the thermostat works, but **Wi-Fi is off.**
* **An external USB-C power supply must be connected for the first set-up.**
* Wi-Fi, the **iNELS Cloud** and the **iNELS app** need the external power supply.
* The 230 V / 5 V adapter is in the package.

## Buttons and display

Six thermostat buttons: temperature up · temperature down · Celsius / Fahrenheit · heating / cooling · fan speed · ON/OFF. Two more **selectable buttons** can control switch units, dimmers or blinds. You can change button functions, icons and logos at **icons.inels.com**.

The display can show:

| Symbol            | Meaning                                              |
| ----------------- | ---------------------------------------------------- |
| Heating / cooling | Which mode is active, and which output is active     |
| Fan speed         | LOW, MED, HIGH or AUTO                               |
| ECO mode          | ECO is on                                            |
| Thermostat OFF    | Regulation is off                                    |
| Manually set      | A manual setting is active                           |
| Wi-Fi             | Wi-Fi connection                                     |
| Battery           | Battery state                                        |
| Window / door     | A window or door is open (from an RFWD-100 detector) |
| Clock             | Time                                                 |
| °C / °F           | Temperature unit                                     |

Selectable views: current temperature, set temperature, and humidity.

## Web configuration

The web interface (Wi-Fi, in a browser) allows the **complete set-up**: basic settings, network parameters, thermostat programs, temperature schedules, the **connection to wireless units** and their **automation**.

## Gateway role

The RFTC-4 has its own web interface where you connect wireless units and set automation. You can reach it through the **iNELS cloud** with the **iNELS app**, or **directly**. Cloud and app access is available with the RFSA-266M; when an RFSA-266M is connected, it can be configured in the web interface.

For the general idea see [Adding paired devices to a gateway](/inels-home/inels-wireless/devices/system-units/adding-paired-devices-to-a-gateway.md).

## Programming card

Units are connected to the RFTC-4 in its web interface — see *Web configuration*.

## Troubleshooting

| Symptom                                    | What to do                                                                                  |
| ------------------------------------------ | ------------------------------------------------------------------------------------------- |
| No Wi-Fi, no cloud, no app                 | Connect the USB-C power supply — Wi-Fi works only with external power                       |
| Cannot do the first set-up                 | The first set-up needs the external USB-C supply, not only batteries                        |
| Cloud and app do not work with other units | Cloud and app access is available with the RFSA-266M. Use the web interface for other units |

## Technical parameters

|                                  |                                                              |
| -------------------------------- | ------------------------------------------------------------ |
| Power supply                     | 2 × AA 1.5 V or USB-C 5 V                                    |
| Internal sensors                 | Temperature 0 to +55 °C, ± 0.5 °C; humidity 0–99 % RH, ± 3 % |
| Radio                            | iNELS RFIO2, 866–922 MHz                                     |
| Wi-Fi                            | 2.4 GHz, only with external power                            |
| Display / buttons                | LCD (VA/TN) 54 × 34 mm / 8 capacitive, backlit, configurable |
| Operating temperature            | 0 to 50 °C, max. 80 % RH                                     |
| Storage temperature              | −20 to 60 °C                                                 |
| Protection                       | IP30 (mounted)                                               |
| Overvoltage category / pollution | II / 2                                                       |
| Working position                 | Horizontal                                                   |
| Installation                     | EU or British box, 60 mm screw spacing; desk stand           |
| Dimensions / weight              | 120 × 80 × 27 mm / 175 g without batteries                   |
| Shape                            | Sharp edges                                                  |
| Colour (glass and plastic)       | White or black                                               |
| Standards                        | EN 60730, EN 63044, EN 301 489, EN 300 220                   |

## Downloads

* [Datasheet RFTC-4 (PDF)](https://www.elkoep.com/media/import/Elko/RFx/RFTC-4/EN/Datasheet_RFTC-4.pdf)
* [EC declaration of conformity (PDF)](https://www.elkoep.com/media/import/Elko/RFx/RFTC-4/EN/EC_Declaration_of_conformity_RFTC-4.pdf)
* [Product page](https://www.elkoep.com/smart-glass-thermostat-battery-powered-rftc-4)