Vent-Axia VAUFHTC Assembly instructions

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User Manual
1. Product description -Area of use. . . . . . . . . . . 2
2. Technical data. . . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. Explanations of the symbols in display . . . . . . 5
4. First time the thermostat is turned on. . . . . . . 5
5. Operation of the thermostat. . . . . . . . . . . . . . . 7
5.1. Constant temperature mode . . . . . . . . . 8
5.2. Event based mode. . . . . . . . . . . . . . . . . . 8
5.3. View measured sensor values. . . . . . . . . 11
6. Changing settings. . . . . . . . . . . . . . . . . . . . . . . . 11
6.1. System settings. . . . . . . . . . . . . . . . . . . . . 11
6.2. Sub-settings, parameters . . . . . . . . . . . . 12
6.3. Event mode settings . . . . . . . . . . . . . . . . 14
6.4. Setting the clock . . . . . . . . . . . . . . . . . . . 16
6.5. Setting the timer . . . . . . . . . . . . . . . . . . . 17
7. Error messages. . . . . . . . . . . . . . . . . . . . . . . . . . 18
8. Resetting the thermostat. . . . . . . . . . . . . . . . . . 18
Installation instructions
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1. PRODUCT DESCRIPTION – AREA OF USE
Thermostat for regulating underfloor electric heating cables,
temperature range within +5 to +40 °C (default). Ref 446174 is
programmable, and regulate the room or floor temperature
automatically. The thermostat can operate in two modes,
constant temperature mode or event mode.
From the factory Ref 446174 will start and run in constant
temperature mode using the room sensor (internal sensor) by
default. The temperature is set by the user, according to his/her
needs at any given time. If switched to event mode the
temperature target will be changed according to the default
program as shown in section 4. In event mode the thermostat
controls the temperature according to time and day. For
weekdays and weekend, different temperatures can be set at
different times. In this way it is possible to reduce the output
during night and day when the user does not need comfort
temperature (automatically). Energy consumption can be
reduced considerably. Please see section 6.3. for settings and
event mode programming.
The thermostat has a (built-in) room sensor and is delivered

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with an external sensor which should be placed (embedded)
into the floor between two heating cable loops, near the floor
surface. Temperature can be regulated by the floor sensor or
the room sensor. A combination mode is also available where
both sensors are used. The floor sensor can then be used to
limit the floor temperature (below the set maximum limit), the
room sensor is used for regulating temperature according to the
set value.
If the heat indication symbol is shown in the display, it means
the thermostat is heating, but the symbol is not directly linked
(synchronized) to the relay controlling the power to the heating
cable.
The thermostat is turned on and off by using the ON/OFF
button. When turned off the settings will be remembered. The
thermostat will also remember its' settings if the power supply
fails (no time limit, EEPROM backup).
2. TECHNICAL DATA
Rated voltage 220-240V
Own consumption < 2 W

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Maximum load 16A（approx. 3600W at rated voltage)
Switch (ON/OFF) Electronic
Temperature range From +5°C to +40°C
(+41°F to +104°F) (default)
Designed working
temperatures 1-50 °C (Room sensor)
for sensors 1-80 °C (Floor sensor)
Dimensions 84x84x40mm(25 mm socket)
Encapsulation IP 21
Length floor sensor
cable 3 m
Cross section area,
connecting wires 0,5 mm² - 2,5 mm²
Max. number of
heating cables 3
Sensing element NTC
Display LCD (blue backlighting)
The thermostat is maintenance free.

3. EXPLANATION OF SYMBOLS IN DISPLAY
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Clock (*)
Measured, or set
temperature if
“SET” is
shown.
Room sensor (*)
* These symbols are only shown if the function/state is active.
4. FIRST TIME THE THERMOSTAT IS TURNED ON
When the Ref 446174 is powered ON for the first time the
following will be shown in the display (heat indication shown
according to temperature level):
Floor sensor (*)
Heat indication
symbol.
Antifreeze (*)
Day of week (*)
Event/operation
mode symbols(*)
Timer (*) Shown when setting even
t
s/modes.
Shown when adjusting general settings
Shown if override
is active

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The thermostat is in constant temperature mode.
If switched to event mode the following predefined program
will start running:
MONDAY - FRIDAY:
Start time for normal operation
(morning) 06.00 Temperature 21°C
Start time for day saving
operation 09.00 Temperature 16°C
Start time for evening operation 17.00 Temperature 21°C
Start time for night saving
operation
22.00 Temperature 16°C

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SATURDAY - SUNDAY:
Start time for normal operation
(morning) 08.00 Temperature 21°C
Day saving operation(deactivated
by default) -- .-- Temperature -- °C
Evening operation(deactivated by
default)
-- .-- Temperature -- °C
Start time for night saving
operation
22.00 Temperature 16°C
For adjusting settings and other operational possibilities
please see section 5 and 6.
5. OPERATION OF THE THERMOSTAT
To change between constant temperature mode and event
mode
This function is linked to the clock function. Enter general
settings (See section 6.1) and go to sub-setting 11:CL (clock
settings). If the clock is disabled, the thermostat will run in
constant temperature mode. Event mode is activated by
activating the clock itself, either 12h AM/PM or 24h (See
section 6.1).

5.1. Constant temperature mode
The display will show the sensor in use and the temperature (or
the set temperature according to settings, see section 6.1 and
sub-setting 12:DF default display).
The set temperature can be adjusted by the user by pressing the
UP and DOWN buttons.
5.2. Event based mode
The temperature is regulated dependent of time and day (as set
by the user).
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In this mode the display will show the sensor in use, the clock,
the current event (in this case "evening operation"), the
temperature (or the set temperature according to settings, see
section 6.1 and sub-setting 12:DF default display), and the
present day (in this case Saturday).
In event mode of operation the thermostat regulates the
temperature according to four different events (the user can
define time and temperature for all four):
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For MONDAY to FRIDAY:
Normal operation (morning) From timeA to B
Day saving operation From time B to C
Evening operation From time C to D
night saving operation
evening operation
(the habitants return to the house)
day saving operation
(the habitants leave the house)
normal operation / morning

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Night saving operation From time D to A
For SATURDAY to SUNDAY there are two different events
by default (up to four events can be activated):
Normal operation (morning) From time E to F
Day saving operation (not defined by default)
Evening operation (not defined by default)
Night saving operation From time F to E
The times and temperatures of all events can be programmed
by the user, please see section 6.3.
Event mode of operation can be overridden by the user. This is
done manually by setting a new temperature with the UP and
DOWN buttons. Leave the thermostat and it will return to
override mode after 10 seconds, OVERRIDE is now shown in
the display.
The thermostat will regulate the temperature according to the
override value until the next event starts. The override can be
cancelled manually by pressing the CLOCK button once (wait
10 seconds).

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5.3. View measured sensor values
This function is only available if sub-setting 12:DF = 01, see
section 6.2. Further on, you cannot see the measured value of a
sensor that is not active, according to sub-setting 10:SE, see
section 6.2.
Press and hold CLOCK button for 3 seconds to see measured
value of floor (external) sensor. (SET symbol will disappear).
Press and hold ON/OFF button for 3 seconds to see measured
value of room (internal) sensor. (SET symbol will disappear).
6. CHANGING SETTINGS
6.1. System settings
First, turn the thermostat OFF, then press and hold the UP and
DOWN buttons
(5 seconds) until the following is shown in the display.

Abbrevation for setting
Current parameter,
which can be adjusted.
Sub-setting numbe
r
This is the menu for general settings, containing 12 different
sub-settings. Sub-setting 01:CF is shown first. Pressing the
CLOCK button lets you cycle between the other 12 different
sub-settings. UP and DOWN keys adjust the current parameter
as shown in the display.
6.2. Sub-settings, parameters
01:CF Set whether to show temperatures in Celsius or
Fahrenheit degrees.00=Celsius, 01= Fahrenheit.
02:DI Shows the dead band range. For information only, the
value cannot be changed.
03:CA Calibration. You can manually set the value of the
current measured temperature. This setting/value applies to
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both internal and external sensor.
04:FR Antifreeze function. 00=Off, 01=On. If function is on
the antifreeze symbol will be shown in the display. See also
sub-setting 05.
05:FS Temperature limitations, antifreeze and maximum floor
temperature.
05=Basic antifreeze, the thermostat will start heating if the
temperature goes below 5 degree Celsius.
CU=User defined settings. Minimum limits as set in
sub-setting 06 and 08 will be used for antifreeze purposes. In
addition if both sensors are active (sensor mode 02) the
thermostat will limit the maximum floor temperature (using the
floor sensor max value) according to the value set in
sub-setting 09.
Active sensor according to setting 10:SE will be used for
temperature measurement. If sensor mode=02 the room
(internal) sensor will trigger the antifreeze function.
06:RO Defines valid minimum setting/value for room
temperature.
07:RO Defines valid maximum setting/value for room

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temperature
08:FL Defines valid minimum setting/value for external/floor
temperature.
09:FL Defines valid maximum setting/value for external/floor
temperature.
10:SE Sensor selection. 00=Room sensor, 01=Floor sensor,
02=Both, combination mode. Set active sensor(s) according to
installation instructions.
11:CL Clock. NO=No clock, thermostat will run in constant
temperature mode, 12h=12 hour clock with AM/PM, 24h=24
hour clock without AM/PM displayed. If either 12h or 24h is
active, event mode will also be activated.
12:DF Default display of temperature: set or measured
temperature. 00=display measured temperature, 01=display set
temperature.
Leave all buttons for 10 seconds to save all settings and return
to normal operation mode. The ON/OFF button cancels and
exits the settings menu.
6.3. Event mode settings

With the clock activated see section 6.1, you can change the
settings for event mode of operation. Press the CLOCK button
once and the following will be displayed:
You are now adjusting settings for weekdays Monday to Friday,
“Normal operation (morning)”. The start-time will be blinking,
and it can now be changed with UP and DOWN buttons. Press
CLOCK button once to jump to the temperature and use UP
and DOWN buttons to set the temperature for this
event/timeframe.
In other words time A (see section 5.2) is set first, thereafter the
temperature for this timeframe. The end time of each
timeframe is defined by the start time of the next timeframe.
Press CLOCK button again to jump to next event, and thereby
defining time B (see section 5.2), and thereafter the other
events. After all four events are defined the settings for
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Saturday and Sunday is defined the same way. For Saturday
and Sunday day saving and evening operation is disabled by
default indicated by "- -" symbols.
During programming, if no buttons are pressed for 10 seconds
settings will be saved and display will return to default display.
Pressing ON/OFF button will cancel and return to default
display.
6.4. Setting the clock
Press DOWN and CLOCK button simultaneously for 5 seconds
to set the clock (clock must be active, sub-setting 11:CL). The
following will be displayed:
The hour is set first.
UP Increases value of blinking parameter
DOWN Decreases value of blinking parameter
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CLOCK Goes to the next setting (minutes, then finally
selection of day)
Leave the thermostat for 10 seconds and all adjustments will be
saved. Press ON/OFF button to cancel.
6.5. Setting the timer
If you want the thermostat active at certain timeframe each day
you can use the timer function. Press and hold UP and CLOCK
buttons simultaneously for 5 seconds to enter timer setup:
First, startup time is defined. Use UP and DOWN buttons to
adjust blinking value, and use CLOCK button to jump to next
value. After startup time is defined, end-time is defined. Leave
all buttons for 10 seconds and settings will be saved. The
thermostat will now switch on during the defined interval, at
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other times it will be off. Set the startup-time equal to the
end-time to disable the function.
7. ERROR MESSAGES
If there is a fault associated with a sensor either E1 or E2 will
be displayed flashing, along with an indication of which sensor
is faulty. E1 means the sensor connection is short-circuited. E2
means there is an open circuit at the sensor connection.
For example, the message below indicates a short-circuit at the
internal room sensor.
8. RESETTING THE THERMOSTAT
To reset the thermostat to its’ original factory settings turn it off,
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then hold ON/OFF button and UP button simultaneously for 10
seconds. All LCD symbols will then light up and the default
data is recovered. Release the buttons.
INSTALLATION INSTRUCTIONS
Vent-Axia VAUFHTC Ref 446174
Product description
VAUFHTC Ref 446174 is a digital thermostat for controlling
electrical underfloor heating cables. The thermostat is equipped
with an integrated room sensor and is delivered with an
external (floor) sensor. The thermostat shall be mounted in a
standard junction box.
Technical data
Rated Voltage: 220-240V, 50/60 Hz
Max. load: 3600 W (16 A at 230 VAC)
IP class: IP 21