Computherm B Series User manual

Wi- thermostat
Instruction Manual
COMPUTHERM B400RF
COMPUTHERM B Series

- 3 -
Contents
1. A GENERAL DESCRIPTIONS OF THE THERMOSTAT 5
2. IMPORTANT WARNINGS AND SAFETY RECOMMENDATIONS 8
3. MEANING OF THE LED LIGHTS ON THE THERMOSTAT AND THE
RECEIVER UNIT 10
4. LOCATION OF THE THERMOSTAT AND THE RECEIVER UNIT 11
5. CONNECTION AND INSTALLATION OF THE THERMOSTAT AND
RECEIVER UNIT AND PUTTING IT INTO OPERATION 12
5.1. Installing the thermostat 13
5.2. Installing the receiver unit 13
5.2.1. Connecting the device to be controlled 14
5.2.2. Connecting the receiver unit to the mains supply 15
5.2.3. Synchronization of the thermostat and the receiver unit 15
6. SETTING UP INTERNET CONTROL 16
6.1. Creating a user account 16
6.2. Connecting the thermostat to Wi-Fi network and the user account 17
6.3. Checking the connection of the thermostat to the Wi-Fi network 20
7. OPERATION OF THE INSTALLED THERMOSTAT 20
8. SETTINGS RELATED TO THE USAGE OF THE THERMOSTAT 21

- 4 -
9. OPERATING MODES AND PROGRAMING OF THE THERMOSTAT 27
10. USING ADDITIONAL TEMPERATURE SENSORS 30
10.1. Connecting additional wireless temperature sensor 31
10.2. Connecting additional wired temperature sensor 32
11. USING OF THE THERMOSTAT DISPLAY 33
12. PRACTICAL ADVICE, TACKLING ANY PROBLEMS THAT MAY OCCUR 34
13. PRODUCT INFORMATION AND TECHNICAL DATA 37

- 5 -
1. A GENERAL DESCRIPTIONS OF THE THERMOSTAT
COMPUTHERM B400RF Wi-Fi thermostat is a wireless switching device that
can be operated by a smartphone, tablet or computer via Internet, and we
especially recommend it for controlling central heating systems but suitable for
irrigation systems, garage doors, for remote control of doors and other electrical
appliances and programmed also control.
It can be easily connected to any gas boiler having a two-wire thermostat
connection point and to any air conditioning apparatus or electrical apparatus,
regardless of whether they have a 24 V or 230 V control circuit.
The device consists of two units. One is the thermostat (transmitter unit), the
other is the receiver unit that controls the boiler. There is a wireless (radio
frequency) connection between the two units, so there is no need to install
a wire between the thermostat and the boiler. The two units are syncronized
during production. The thermostat and its receiver have their own security code,
which guarantees the safe operation of the device. See Chapter 5and 11 for
installation, connection and sycronization of the receiver with the thermostat.
The thermostat does not transmit continuously, but repeats its current switching
command every 5 minutes, therefore the heating / cooling control is provided
even after a power failure.

- 6 -
The portability of the thermostat o󰀨ers the following advantages:
– no need to lay a cable, which is especially advantageous when old
buildings are being modernized,
– the optimal location of the device can be selected during operation,
– it is also advantageous when you intend to locate the thermostat in
di󰀨erent rooms in the course of the day (e.g. in the living room during the
day but in the bedroom at night).
boiler
receiver
unit
230 V AC
50 Hz
thermostat
230 V AC
50 Hz

- 7 -
The range of the transmitter built in the thermostat in open area is approx. 250
m. This distance can be signicantly reduced inside a building, especially if
a metal structure, reinforced concrete, or adobe wall gets in the way of radio
waves.
The device can be easily controlled via the Internet and the touch screen,
and its operating status (ON / OFF) can be continuously monitored. The
device also o󰀨ers the possibility of automatic control based on temperature
and time. The data measured by the humidity and brightness sensor built
into the thermostat are displayed on the user interface, which provides to
the user additional information about the thermostat’s environment. Multiple
thermostats, even installed in di󰀨erent locations, can be registered and
controlled by using the same user prole.
COMPUTHERM B400RF Wi-Fi thermostats can be used to control:
• gas boilers
• an existing heating/cooling system remotely
• electric water heaters
• solar systems
• certain groups of other electric devices
With the help of the product the heating/cooling system of your at, house or
holiday home can be made controllable from any place and at any time. This

- 8 -
product is especially useful when you do not use your at or house according
to a predened schedule, you leave your home for an uncertain period of
time during the hating season or you intend to use your holiday home during
the heating season as well.
The simultaneous use of several COMPUTHERM room thermostats and
one COMPUTHERM Q4Z zone controller provides the possibility for the
thermostats to also control a pump or a zone valve in addition to starting the
heater or cooler. This way it is easy to divide a heating / cooling system into
zones, thanks to which the heating / cooling of each room can be controlled
separately, thus greatly increasing comfort. Furthermore, the zoning of the
heating / cooling system will greatly contribute to the reduction of energy
costs, as due to this only those rooms will be heated / cooled at any time
where it is required.
2. IMPORTANT WARNINGS AND SAFETY RECOMMEN-
DATIONS
• Before starting to use the device, please study carefully the instructions for
use and follow strictly the instructions therein.
• The thermostat was designed for business or household (not industrial)
use, and can be used to control any electric device whose performance

- 9 -
does not exceed 3.6 kW (loadability: max 30 V DC / 250 V AC; 16 A [4 A
inductive]).
• Before starting to use the thermostat, make sure that the Wi-Fi network
is reliably accessible at the place where you intend to use the apparatus.
• This device has been designed for indoor use. Do not use it in a humid,
dusty or chemically aggressive environment.
• This device is a thermostat that can be controlled via a wireless Wi-Fi
network. To prevent jamming, keep it away from such electric equipment
which may interfere with wireless communications.
• The manufacturer will assume no responsibility for any possible direct or
indirect damages or income losses incurring during the use of the device.
• The device will not work without power supply, but the thermostat is able to
memorize settings. In case of power failure (outage) it can resume operation
without any external intervention after the power supply is restored. If you
intend to use the device in an environment where power outages occur
frequently, for safety purposes we propose you to control proper operation
of the thermostat regularly.

- 10 -
• Before actually starting to control the device connected to the
thermostat, make sure that the device is perfectly functioning when
it is controlled by the thermostat and it can be operated reliably.
• The software of the thermostat and the telephone application is constantly
upgraded and updated. For proper operation please check regularly
whether there is any accessible software or telephone application update,
and always use their latest version! Due to constant updates it is possible
that some functions of the device and the applications operate and appear
in a way other than described in these instructions for use.
3. MEANING OF THE LED LIGHTS ON THE THERMOS-
TAT AND THE RECEIVER UNIT
The operating status of the thermostat is indicated by an LED as detailed below:
• When a wireless signal is received, the red LED ashes.
• When a wireless signal is output, the green LED ashes.
• When communicating with a server, the purple LED ashes.
The ashes of the LEDs can be turned o󰀨 in the touch screen settings.
The operating status of the receiver is indicated by a red and a blue LED as
detailed below:

- 11 -
• When wireless signal is received, the blue LED ashes.
• In synchronization mode, the blue LED ashes every 0.5 seconds.
•If the receiver unit is not connected to the thermostat, the blue
LED ashes every 15 seconds.
• If the receiver unit output is on, the red LED is lit continuously.
4. LOCATION OF THE THERMOSTAT AND THE RECEIV-
ER UNIT
It is expedient to install the thermostat on the wall of a room used regularly or for
a prolonged stay, so that it is located in the direction of natural air movement in
the room, but do not expose it to draughts of air or extreme heat e󰀨ects (e.g. solar
radiation, refrigerator or chimney). Do not use in wet, chemically agressive or dusty
environment. Its optimal position is at a height of 0.75 - 1.5 m from the oor level.
The receiver of the COMPUTHERM B400RF thermostat should be installed near
the boiler, in a place protected from moisture, dust, chemicals and heat. When
selecting the location of the receiver, also take into account that the propagation
of radio waves is caused by large metal objects (eg boilers, bu󰀨er tanks, etc.) or
metal building structures may be adversely a󰀨ected. If possible, we recommend
that you install the receiver at a distance of at least 1-2 m from the boiler and
other large metal structures, at a height of 1.5-2 m, to ensure interference-free
radio frequency communication. We recommend that you check the reliability

- 12 -
of the radio frequency connection at the selected location before installing the
receiver.
ATTENTION! Do not install the receiver unit under the boiler cover or in the
immediate vicinity of hot pipes, as this may damage the components of the
appliance and endanger the wireless (radio frequency) connection. To avoid
electric shock, entrust a professional to connect the receiver to the boiler.
IMPORTANT WARNING! If the radiator valves in your at are equipped with
thermostat head then set the thermostat head to maximum level in the room
where you intend to locate the room thermostat or replace the thermostat head
of the radiator valve with manual regulating knob, otherwise the thermostat head
may disturb the temperature control in the at.
5. CONNECTION AND INSTALLATION OF THE THER-
MOSTAT AND RECEIVER UNIT AND PUTTING IT
INTO OPERATION
ATTENTION! Make sure that the COMPUTHERM B400RF thermostat and the
apparatus to be controlled are de-energized while putting them into operation.
The device should be installed and put into operation by a competent person!
If you do not possess the necessary skills and qualications, please get in
touch with an authorized service.

- 13 -
Caution! The modication of the device poses a risk of electric shock or
breakdown!
5.1. Installing the thermostat
Connect the cable in the product box to the micro USB socket on the back of
the thermostat. Then connect the other end of the USB cable to the adapter
included in the package and connect it to the 230 V mains (Figure 1).
5.2. Installing the receiver unit
The DIN rail in the thermostat package allows the receiver to be mounted on
a wall. To do this, remove the screws and dowels in the plastic bag from the
packaging and use them to secure the on the wall of the DIN rail. Then snap the
receiver onto the DIN rail. First the top of the back of the receiver (according to
the position of the inscriptions) hook it into the rail and then snap on the bottom
as well.
Figure 1.

- 14 -
5.2.1. Connecting the device to be controlled
The receiver unit controls the boiler or air conditioner through a potential-free
alternating relay with connection points: NO, COM and NC. The connection
points for the room thermostat of the heating or cooling device to be controlled
should be connected to the NO and COM terminals of the terminal that are
normally open (Figure. 2).
Figure 2. Figure 3.
Boiler
Water
heater
Button Button
receiver unit receiver unit

- 15 -
In case the device to be controlled does not have a thermostat connection point,
the power supply wire of the device must be cut o󰀨 and connected to the NO and
COM connection points of the thermostat (Figure 3).
5.2.2. Connecting the receiver unit to the mains supply
The 230 V mains supply should be connected to terminal 2 (N-L) on the left
side of the receiver with a two-wire cable (Figure. 2). It is not necessary to pay
attention to the phase correctness when connecting the power supply. It is not
necessary to connect a ground wire because the product is double insulated.
5.2.3. Synchronization of the thermostat and the receiver unit
The thermostat and its receiver unit are synchronized in the factory. If the
communication between the two units is interrupted, resynchronization can be
accomplished as follows:
• Press the button on the side of the receiver unit for 5 seconds. The blue LED
inside the product will then ash rapidly.
• Use the thermostat’s touch screen to enter the Settings menu and select
Pairing. After a short time, the display shows „Successful pairing!” text and
the synchronization is complete.

- 16 -
6. SETTING UP INTERNET CONTROL
6.1. Creating a user account
The thermostat can also be controlled from a smartphone, tablet (with a free app),
a computer (via a web interface) and the touch screen. For smartphones and
tablets, the free COMPUTHERM B Series app can be downloaded for iOS and
Android operating systems. The applications accessible throught the following link
or using QR code:
https://computherm.info/en/wi-fi_thermostats

- 17 -
A user account must be created to control the thermostat. This can be
done in the browser at https://computhermbseries.com/ and in the
phone application. An e-mail address, name and password are required for
registration. You can also log in with an existing Facebook or Google account
to control the product without registration. After registration, you must log in
to the created user account.
6.2. Connecting the thermostat to Wi-Fi network and the user account
To be able to control the device remotely, the thermostat needs to be connected
to the Internet via a Wi-Fi network. The already set COMPUTHERM B400RF can
work according to a pre-set program without the need for a permanent internet
connection.
Attention! The thermostat can only be connected to a 2,4 GHz Wi-Fi network.
There are 3 options to connect the product to a Wi-Fi network and add it to a
user account. For each version, use the thermostat’s touch screen to enter the
Settings menu and then select Wi-Fi. Here you can choose from the following
options:

- 18 -
• SmartCong:
If you use the COMPUTHERM B Series application, you can have a quick
synchronization. Enable the Wi-Fi connection on your smartphone or tablet
and connect your device to the 2.4 GHz Wi-Fi network to which you want to
connect the thermostat. Turn on the location service (GPS location data)
on your phone and give all the requested permissions to the application
in order to work properly. After logging in within the app, touching the “+”
icon in the upper right corner will bring up the sync menu. Touching the
“SMART CONFIG” button will bring up a new page. The name of the Wi-Fi
network you want to use appears in the line below the “SSID” text and the
corresponding password must be typed. Then, by touching the “Search”
button, the thermostat will connect to the Internet after a short time and
will be added to the user account you are currently using.
• Access Point (Wi-Fi AP):
If you want to conect the product in the traditional way (eg. by using a
web browser), you need to connect it to your Wi-Fi network starting with
the word “Computherm” created by the thermostat on your smartphone,
tablet or laptop. You can also do this on your smartphone and tablet by
scanning the QR code that appears on the thermostat display. Then, on
the automatically opened page, select the local Wi-Fi network you want to

- 19 -
use and enter the corresponding password. Then click the “Connect!” to
connect your device to a Wi-Fi network. If the above page does not appear
on your device, type the IP address 192.168.10.1 into your browser. The
aforementioned connection can be made on the page that appears here.
If the connection was successful, the thermostat will display “Successful
connection!” text.
The product must then be assigned to a user account. To do this, log in
to the previously created account and click on the “+” icon in the upper
right corner of the main page. Enter the 10-digit serial number from the
bottom of the thermostat in the box below “Add Device”. When entering
the serial number, you do not have to pay attention to the use of uppercase
and lowercase letters. You can then add the device to the user account by
clicking the “SEARCH” button.
• Connecting by using the thermostat’s touch screen:
Select the Wi-Fi network to which you want to connect the thermostat, then
use the touch screen to enter its password. The successful connection is
indicated by the thermostat display.
The product must then be assigned to a user account. To do this, log in to
the previously created account and select the “+” icon in the upper right

- 20 -
corner of the main page. After opening the “Serial number” menu under
the “SMART CONFIG” text, enter the 10-digit serial number from the
bottom of the thermostat in the eld under “Add device”. When entering
the serial number, you do not have to pay attention to the use of uppercase
and lowercase letters. You can then add the device to the user account by
clicking the “SEARCH” button.
6.3. Checking the connection of the thermostat to the Wi-Fi network
In the upper right corner of the thermostat display the icon’s color
indicates the status of the Wi-Fi connection, as described below:
• Black: the thermostat is properly connected to the Wi-Fi network
• Yellow: the thermostat is connected to the Wi-Fi network, but there is
no connection to the server
• Red: the thermostat is not connected to the Wi-Fi network
7. OPERATION OF THE INSTALLED THERMOSTAT
The thermostat controls the device connected to it (e.g. gas boiler or pump)
based on the measured temperature and the currently (manually or programmed)
set temperature, taking into account the switching sensitivity of the thermostat
(factory default ±0.1 °C). This means that if the thermostat is set to heating mode