Vaillant VRT 350 User manual

en Operating instructions
VRT 350
0020135485_02 - 21.07.2022

2Operating instructions 0020135485_02
Operating instructions
Contents
1 Safety .................................................................... 3
1.1 Action-related warnings ......................................... 3
1.2 Intended use .......................................................... 3
1.3 General safety information .................................... 4
2 Notes on the documentation .............................. 6
2.1 Observing other applicable documents ................. 6
2.2 Storing documents................................................. 6
2.3 Validity of the instructions...................................... 6
3 Product description............................................. 6
3.1 Unit design............................................................. 6
3.2 Control function...................................................... 7
3.3 Frost protection function ........................................ 7
3.4 Data plate .............................................................. 8
3.5 Serial number ........................................................ 8
3.6 CE marking ............................................................ 8
4 Operation.............................................................. 8
4.1 Operating structure................................................ 8
4.2 Operating concept ............................................... 10
5 Operating and display functions...................... 14
5.1 Information........................................................... 14
5.2 Settings................................................................ 15
5.3 Operating modes ................................................. 21
5.4 Special operating modes ..................................... 22
5.5 Messages ............................................................ 23
6 Troubleshooting ................................................ 25
6.1 Detecting and eliminating faults........................... 25
7 Care and maintenance ...................................... 25
7.1 Caring for the product.......................................... 25
8 Decommissioning.............................................. 25
8.1 Replacing the control........................................... 25
8.2 Recycling and disposal........................................ 25
9 Guarantee and customer service..................... 25
9.1 Guarantee............................................................ 25
9.2 Customer service................................................. 25
Appendix ............................................................................ 26
A Overview of operating levels............................ 26
B Technical data.................................................... 31
B.1 Control ................................................................. 31
Index ................................................................................... 32

0020135485_02 Operating instructions 3
1 Safety
1.1 Action-related warnings
Classification of action-related warnings
The action-related warnings are classified in
accordance with the severity of the possible
danger using the following warning symbols
and signal words:
Warning symbols and signal words
Danger!
Imminent danger to life or risk of
severe personal injury
Danger!
Risk of death from electric shock
Warning.
Risk of minor personal injury
Caution.
Risk of material or environmental
damage
1.2 Intended use
There is a risk of injury or death to the user or
others, or of damage to the product and other
property in the event of improper use or use
for which it is not intended.
The product is intended for controlling a heat-
ing installation with heat generators from the
same manufacturer via the eBUS interface
and the domestic hot water generation for a
connected domestic hot water cylinder.
Intended use includes the following:
–observance of the operating instructions
included for the product and any other in-
stallation components
–compliance with all inspection and main-
tenance conditions listed in the instruc-
tions.
This product can be used by children aged
from 8 years and above and persons with re-
duced physical, sensory or mental capabilities
or lack of experience and knowledge if they
have been given supervision or instruction
concerning use of the product in a safe way

4Operating instructions 0020135485_02
and understand the hazards involved. Chil-
dren must not play with the product. Clean-
ing and user maintenance work must not be
carried out by children unless they are super-
vised.
Any other use that is not specified in these
instructions, or use beyond that specified in
this document, shall be considered improper
use. Any direct commercial or industrial use is
also deemed to be improper.
Caution.
Improper use of any kind is prohibited.
1.3 General safety information
1.3.1 Danger caused by improper
operation
Improper operation may present a danger to
you and others, and cause material damage.
▶Carefully read the enclosed instructions
and all other applicable documents, par-
ticularly the "Safety" section and the warn-
ings.
▶Only carry out the activities for which in-
structions are provided in these operating
instructions.
1.3.2 Risk of scalding from hot water
There is a risk of scalding at the hot water
draw-off points if the set target temperature
is greater than 60 °C. Young children and
elderly persons are particularly at risk, even
at lower temperatures.
▶Select a moderate target temperature.
1.3.3 Danger caused by a malfunction
▶Ensure that room air can circulate freely
around the control, and that the control is
not covered by furniture, curtains or other
objects.
▶Ensure that all radiator valves in the room
where the control is installed are fully open.
▶Only operate the heating installation when
it is in a technically perfect condition.
▶Ensure that any faults and damage that
may negatively affect safety are eliminated
immediately.

0020135485_02 Operating instructions 5
1.3.4 Risk of material damage caused by
frost
▶Ensure that the heating installation always
remains in operation during freezing con-
ditions and that all rooms are sufficiently
heated.
▶If you cannot ensure the operation, have a
competent person drain the heating install-
ation.
1.3.5 Frost damage caused by switching
the unit off
If you switch off the heating installation, parts
of the heating installation may be damaged by
frost.
▶Do not disconnect the heat generator from
the power grid.
▶Leave the heating installation main switch
in the "1" position.
1.3.6 Frost damage caused by excessively
low room temperature
If the room temperature is set too low in indi-
vidual rooms, sections of the heating installa-
tion might be damaged by frost.
▶If you are absent during a frosty spell, en-
sure that the heating installation remains in
operation and the rooms are warmed ad-
equately.
▶Please note the frost protection function.

6Operating instructions 0020135485_02
2 Notes on the documentation
2.1 Observing other applicable documents
▶Always observe all operating instructions enclosed with
the installation components.
2.2 Storing documents
▶Store these instructions and all other applicable docu-
ments for further use.
2.3 Validity of the instructions
These instructions apply only to:
Product article number
VRT 350 0020124475
3 Product description
3.1 Unit design
1
3
5
4
6
2
1 Display
2 Wall base
3 Diagnosis socket
4 Right selector button
5 Rotary knob
6 Left selector button

0020135485_02 Operating instructions 7
3.2 Control function
The control controls the Vaillant heating installation and do-
mestic hot water generation of a connected domestic hot wa-
ter cylinder.
If the control is installed in a living room, you can operate the
heating installation and domestic hot water generation from a
living room.
3.2.1 Heating installation
The controller is a room-temperature-controlled controller
and must be installed in the living room. You can use the
controller to set the desired temperature for different times
of the day and for different days of the week. The temperat-
ure sensor measures the room temperature and sends the
values to the controller. At lower room temperatures, the con-
troller switches the heater on. Once the room temperature
reaches the desired set temperature, the controller switches
the heater off. The controller therefore reacts to the fluctu-
ations of the room temperature and constantly controls the
room temperature to the temperature that you have set.
Data exchange and power supply on the controller are via
an eBUS interface. The controller can be equipped with the
Vaillant diagnosis software and the Vaillant Internet commu-
nication system for remote diagnosis and remote settings.
3.2.2 Domestic hot water generation
You can use the control to set the temperature and time for
domestic hot water generation. The heat generator heats the
water in the domestic hot water cylinder until it reaches the
set temperature. You can set a time period during which hot
water should be available in the domestic hot water cylinder.
3.2.3 VR 66 Control Centre
If a VR 66 Control Centre is connected, you can control two
independent heating circuits with just one VRT 350 control-
ler; e.g. one heating circuit is in the single-occupancy house
and the second heating circuit is in a guest apartment in
this building. In this case, one controller is always the main
controller (Zone 1) and the other controller is the auxiliary
controller (Zone 2). For Zone 1, which is controlled via the
main controller, all of the functions are available to you. For
Zone 2, you can use the auxiliary controller to set the desired
temperature for different times of the day and different days
of the week.
3.3 Frost protection function
The frost protection function protects the heating system and
apartment from frost damage.
The frost protection function monitors the room temperature.
If the room temperature
–falls below 5 °C, the controller switches the heater on and
controls the system to a target room temperature of 5 °C.
–exceeds 5 °C, the heater is switched off but the room
temperature monitoring remains active.

8Operating instructions 0020135485_02
3.4 Data plate
The data plate is located inside the control and is not access-
ible from the outside.
3.5 Serial number
The 10-digit article number can be found in the serial num-
ber. You can view the serial number under Menu →Inform-
ation Serial number. The article number is found in the
second line of the serial number.
3.6 CE marking
The CE marking shows that the products comply with the
basic requirements of the applicable directives as stated on
the declaration of conformity.
The declaration of conformity can be viewed at the manufac-
turer's site.
4 Operation
4.1 Operating structure
4.1.1 Adjustment and display levels
The product has two adjustment and display levels.
The end user level contains information and setting options
that you require as the end user.
Overview of operating levels (→Page 26)
The installer level is reserved for the competent person. It is
protected by a code. Only competent persons may change
any settings in the installer level.
4.1.2 Menu structure design
The menu structure of the controller is split into three levels.
There are two selection levels and one setting level. From
the basic display, you can access selection level 1 and, from
there, you can access the menu structure for one level up or
down. The setting level is accessed from the lowest selection
level.

0020135485_02 Operating instructions 9
4.1.3 Basic display
Auto 01.07.11
°C
19,5
15:34
Desired temperature 20,0°C
Menu Mode
1
2
3
4
8
7
5
6
1 Date
2 Current room temperat-
ure
3 Time
4 Current function of the
right-hand selector but-
ton (soft key function)
5 Current function of the
left-hand selector button
(soft key function)
6 Desired temperature
7 Symbol for heating
mode in Auto mode
8 Mode set for the heating
mode
The basic display shows the current settings and values of
the heating installation. If you make a setting on the control,
the display on the screen switches from the basic display to
the display with the new setting.
The basic display appears when you
–press the left-hand selection button and thus exit selec-
tion level 1.
–do not operate the control for more than 5 minutes.
4.1.3.1 Symbols for the Auto operating mode
Symbol Meaning
Day mode: Within a set time period
Night mode: Outside a set time period
4.1.3.2 Soft key function
Both selection buttons have a soft key function. The current
functions of the selection buttons are displayed in the bottom
display line. Depending on the selection level selected in
the menu structure, the list entry or the value, the current
function for the left- and right-hand selection buttons may be
different.
If, for instance, you press the left-hand function button, the
current function of the left function button switches from
Menu to Back.
4.1.3.3 Menu
If you press the left-hand selection button, Menu, you switch
from the basic display to selection level 1 of the menu struc-
ture.

10 Operating instructions 0020135485_02
4.1.3.4 Operating mode
If you press the right-hand selection button, Operating
mode, you access the settings directly from the basic display
under Operating mode.
4.1.3.5 Desired temperature
Depending on the operating mode, the desired temperature
may be greyed out on the basic display. This is the case, for
example, in Summer mode. As heating is not operational in
Summer mode, and therefore the heating circuit is off, there
is no desired temperature.
4.1.4 Selection level
Menu
Information
Desired temperatures
Time programmes
Back Select
1
4
3
2
1 Scroll bar
2 Current functions of
the right- and left-hand
selection buttons
3 Selection level list
entries
4 Current function or
selection level
Through the selection levels, you navigate to the setting level
in which you wish to read or change settings.
4.1.5 Setting level
HEATING 1
Day
Night set-back
Back Change
20,0°C
15,0°C
1
3
2
5
4
1 Current selection level
2 Values
3 Selection (current selec-
tion)
4 Current functions of
the right- and left-hand
selection buttons
5 Setting level
In the setting level, you can select the values you want to
read or change.
4.2 Operating concept
The control is operated using two selection buttons and a
rotary knob.
The display shows a highlighted selection level, a setting
level or a highlighted value with white font on a black back-
ground. A flashing, highlighted value means that you can
change the value.

0020135485_02 Operating instructions 11
If you do not operate the control during a period of more than
5 minutes, the basic display appears again.
4.2.1 Example: Operation in the basic display
From the basic display, you can change the Desired day
temperature directly for the current day by turning the rotary
knob.
Desired day temperature
Only today: 18°C
For permanent change
Press OK
OK
In the display, a request appears asking if you want to
change the Desired day temperature for the current day or
on a permanent basis.
4.2.1.1 To change the Desired day temperature for
the current day only
▶Turn the rotary knob to set the desired temperature.
◁The display switches back to the basic display after
12 seconds. The set desired temperature applies only
until the end of the active time period of the current
day.
4.2.1.2 Changing the Desired day temperature
permanently
1. Turn the rotary knob to set the desired temperature.
2. Press the right-hand selection button, OK.
◁The display switches to the basic display. The new
desired day temperature is applied permanently.
4.2.2 Operating example, changing the date
Auto 01.07.11
°C
19,5
15:34
Desired temperature 20,0°C
Menu Mode
1. If the display does not show the basic display, press
the left-hand selection button, Back, until the basic
display appears again.
2. Press the left-hand selection button, Menu.
◁The control is now in selection level 1. The left-hand
selection button now has the function Back (to the
previous selection level), the right-hand selection
button has the function Select (to the next selection
level).

12 Operating instructions 0020135485_02
Menu
Information
Desired temperatures
Time programmes
Back Select
3. Turn the rotary knob until the Default settings list entry
is highlighted.
Menu
Time programmesTime programmes
Days away scheduling
Basic settings
Back
Select
4. Press the right-hand selection button, Select.
◁The control is now in selection level 2.
Basic settings
Language
Date/time
Display
Back Select
5. Turn the rotary knob until the Date/Time list entry is
highlighted.
Basic settings
LanguageLanguage
Date/timeDate/time
Display
Back Select
6. Press the right-hand selection button, Select.
◁The control is now in the Date setting level. The
value for the day is highlighted. The left-hand selec-
tion button now has the function Back (to go back
to the previous selection level), the right-hand se-
lection button has the function Change (the value).

0020135485_02 Operating instructions 13
Date/time
Time
Date
Daylight saving time
:1508
13.03.11
Off
Back Change
7. Press the right-hand selection button, Change.
◁The highlighted value starts to flash; you can now
change the value by turning the rotary knob.
◁The left-hand selection button now has the function
Cancel (the change); the right-hand selection but-
ton has the function OK (to confirm the change).
Date/time
Time
Date
Daylight saving time
:1508
13.03.11
Off
Cancel OK
8. Turn the rotary knob to change the value.
Date/time
Time
Date
Daylight saving time
:1508
14.03.11
Off
Cancel OK
9. Press the right-hand selection button, OK, to confirm
the change.
◁The control has stored the changed date.
Date/time
Time
Date
Daylight saving time
:1508
14.03.11
Off
Back Change
10. If the highlighted value that is flashing is correct, press
the right-hand selection button OK again.
◁The left-hand selection button now has the function
Back.
11. Press the left-hand selection button Back repeatedly
to revert back to the previous selection level and to
access the basic display from selection level 1.

14 Operating instructions 0020135485_02
5 Operating and display functions
The path details given at the start of each function descrip-
tion indicate how you reach this function in the menu struc-
ture.
You can use the left-hand selection button Menu to set the
operating and display functions.
You can find which functions are available for zone 2 via the
auxiliary control in the "Overview of operating levels" table or
in the menu tree overview.
5.1 Information
5.1.1 Reading the system status
Menu →Information →System status
–Under System status, you can read a list containing the
current values for the system: status, water pressure, hot
water generation and the current values for HEATING 1.
There is also information under System status
–regarding the active time period (Auto day temp until),
–regarding exceptions in the timer programs that you may
have set using the Days away from home function.
Only the desired temperatures for Day temperature and Set-
back temperature can also be set directly under System
status. All other values are set in other places in the menu
structure, as described in the following sections.
5.1.2 Reading the list of status messages
Menu →Information →System status →Status
–If no service is required and no faults have occurred, the
value OK is shown next to Status. If a service is required
or an error has occurred, the value Not OK is shown
next to Status. In this case, the right-hand selection but-
ton has the function Display. If you press the right-hand
selection button Display, the list of status messages is
shown in the display.
5.1.3 Read competent person contact details
Menu →Information →Contact details
–If the competent person entered their company name and
telephone number during the installation, you can read
this data under Contact details.
5.1.4 Reading the serial number and article
number
Menu →Information →Serial number
–Serial number shows the serial number of the control,
which the competent person may require you to tell him.
The article number is found in the second line of the serial
number.

0020135485_02 Operating instructions 15
5.2 Settings
5.2.1 Setting desired temperatures
This function is used to set the desired temperatures for
HEATING 1 and hot water generation.
5.2.1.1 Heating circuit
Caution.
Risk of damage due to frost.
If rooms are not adequately heated, this may
cause damage to the building and to the heat-
ing installation.
▶If you are absent during a frosty spell, en-
sure that the heating installation remains
in operation and provides adequate frost
protection.
Menu →Desired temperatures →HEATING 1
–You can set two different desired temperatures for the
heating circuit.
–The desired day temperature is the temperature you
wish to have in the rooms during the day or when you are
at home (Comfort mode).
–The desired night temperature is the temperature that
you wish to have in the rooms during the night or when
you are away from home (Set-back mode).
5.2.1.2 Domestic hot water generation
Danger!
Risk of scalding caused by hot water.
There is a risk of scalding at the domestic
hot water draw-off points if the temperatures
are greater than 60 °C. Young children and
elderly persons are particularly at risk, even at
lower temperatures.
▶Select the temperature so that nobody is
at risk.
Menu →Desired temperatures →Domestic hot water
–You can only use the control's functions and setting op-
tions for domestic hot water generation if a domestic hot
water cylinder is connected to the heating installation.
You can set the desired DHW circuit temperature for the
domestic hot water circuit.

16 Operating instructions 0020135485_02
5.2.2 Setting time programmes
5.2.2.1 Showing time periods for one day
18:0016:30 22:30
16 °
21 °
Temperature
Time
Desired
day
temperature
20:00
Period 1
Period 2
Desired
day
temperature
Desired
night
temperature
Desired night temperature
The Time programmes function can be used to set the time
period for the heating circuit and hot water generation.
If you have not set any time periods, the controller uses the
time periods set in the factory settings.
5.2.2.2 Setting time periods for days and blocks
For each day and block, you can set up to three time periods.
The time periods set for a day have priority over the time
periods set for a block.
Desired Day temperature: 21 °C
Desired Night temperature: 16 °C
Time period 1: 16.30 –18.00
Time period 2: 20.00 –22.30
Within the time periods, the control brings the room temperat-
ure to the set desired Day temperature (day mode).
Outside the time period, the control brings the room temper-
ature to the set desired Night temperature (night mode).
5.2.2.3 Setting time programmes quickly
If, for example, you require a different time period for just
one working day in the week, first set the times for the entire
block Monday –Friday". Then set the different time period
for the working day.

0020135485_02 Operating instructions 17
5.2.2.4 Displaying and changing different times in
the block
Monday - Sunday
Period 1:
Period 2:
Period 3:
!! : !! - !! : !!
!! : !! - !! : !!
!! : !! - !! : !!
Back Select
If you view a block in the display and have defined a different
period for a day in this block, then the display indicates the
different time periods in the block with !! .
Individual dates vary from
the selected time programme
Mo-Su.
OKBack
If you press the right-hand selection button Select, a mes-
sage appears on the display which informs you about differ-
ent time periods. You do not need to adjust the times.
The set times for the block marked with !! can be viewed and
changed if you press the right-hand selection button OK in
the display.
5.2.2.5 For the heating circuit
Menu →Timer programs →HEATING 1
–The time programmes are only effective in the Automatic
mode (→Page 21). The desired temperature that you set
in the Desired temperatures function applies in each set
time period. Within the time period, the controller switches
to Comfort mode and the heating circuit heats the con-
nected rooms up to the desired day temperature. Out-
side this time period, the controller switches to the set-
back mode and the heating circuit heats the connected
rooms to the desired set-back temperature.
Set the time period for the heating circuit so that each time
period:
–starts approx. 30 minutes before the time at which the
rooms should reach the desired day temperature.
–ends approx. 30 minutes before the time at which the
rooms should reach the desired set-back temperature.
5.2.2.6 For domestic hot water generation
Menu →Timer programs →Hot water circuit
–You can only use the control's functions and setting op-
tions for domestic hot water generation if a domestic hot
water cylinder is connected to the heating installation.

18 Operating instructions 0020135485_02
For domestic hot water generation, the time programmes are
only effective in Automatic mode.
In each time period set, the desired DHW circuit temperat-
ure applies. At the end of a time period, the control switches
the domestic hot water generation off until the start of the
next time period.
Set the time periods for hot water generation so that each
time period:
–starts approx. 30 minutes before the time at which the
water in the domestic hot water cylinder should have
reached the desired DHW circuit temperature.
–ends approx. 30 minutes before the time at which you no
longer need any hot water.
5.2.3 Days away from home scheduling
Menu →Days away from home scheduling →HEATING 1
–You can use this function to set a period with a start and
end date and a temperature for days during which you
are away from home. Thus, you do not need to change
time periods for which you have set, for example, no re-
duction of the desired temperature over the course of the
day.
Frost protection is activated.
While the Days away from home scheduling function is
activated, it has priority over the set operating mode. At the
end of the specified period, or if you cancel the function, the
heating installation returns to the pre-set mode.
5.2.4 Select language
Note
During installation, the competent person sets the
desired language. All functions are displayed in
the set language.
Menu →Basic settings →Language
–If the language of e.g. a service technician differs from
the set language, you can change the language using this
function.
Caution.
It may not be possible to operate the con-
trol if the wrong language is selected.
If you select a language that you do not un-
derstand, you can no longer read the text in
the control display and can no longer operate
the control.
▶Only select a language that you under-
stand.
However, if the text in the display should appear in a lan-
guage that you do not understand, you can set a different
language.

0020135485_02 Operating instructions 19
5.2.4.1 Setting your language
1. Press the left-hand selection button repeatedly until the
basic display appears.
2. Press the left-hand selection button again.
3. Rotate the rotary knob clockwise until the dotted line
appears.
4. Turn the rotary knob anti-clockwise until the second list
entry above the dotted line is highlighted.
5. Press the right-hand selection button twice.
6. Turn the rotary knob until you find a language that you
understand.
7. Press the right-hand selection button.
5.2.5 Setting the date
Menu →Basic settings →Date/Time →Date
–Select this function to set the current date. All control
functions that contain a date relate to the set date.
5.2.6 Setting the time
Menu →Basic settings →Date/Time →Time
–Select this function to set the current time. All control
functions that contain a time relate to the set time.
5.2.7 Changing over to daylight saving time
Menu →Basic settings →Date/Time →Day-light savings
–You can use this function to set whether the controller
automatically changes over to daylight saving time, or
whether you want to do this manually.
–Auto: The controller automatically changes over to day-
light saving time.
–Off: You have to change over to daylight saving time
manually.
Note
Daylight saving time means Central European
summer time: Start = last Sunday in March, End
= last Sunday in October.
5.2.8 Set display contrast
Menu →Basic settings →Display →Display contrast
–You can set the display contrast in relation to the bright-
ness of the surroundings, to ensure that the display is
clearly legible.
5.2.9 Setting the offset room temperature
Menu →Basic settings →Offset →Room temperature
–A thermometer is integrated in the controller for measur-
ing the room temperature. If you have another thermo-
meter in the same room and compare the values with
each other, the temperature values may constantly dif-
fer from each other.
Example

20 Operating instructions 0020135485_02
One room thermometer constantly shows a temperature that
is one degree higher than the current room temperature on
the controller display. With the Room temperature func-
tion, you can offset the temperature difference in the con-
troller display by setting a correction value of +1 K (1 K cor-
responds to 1 °C). K (Kelvin) is a unit for the temperature dif-
ference. Inputting a correction value affects the room temper-
ature compensator.
5.2.10 Enter the heating circuit name
Menu →Basic settings →Change heating circuit naming
–You can now modify the factory-set heating circuit names
as you wish. The name is limited to 10 characters.
5.2.11 Reset to factory settings
You can reset the settings for the Time programmes or for
Everything to the factory setting.
Menu →Basic settings →Factory reset →Time
programmes
–With Time programmes, you reset all the settings you
have made in the Time programmes function to the de-
fault setting. All other settings that include times, such as
Date/Time, are not affected.
While the control is resetting the time programme settings to
the default settings, In process is shown on the display. The
basic display is then displayed.
Caution.
Risk of a malfunction.
The Everything function restores all settings
to the factory settings, including those set by
the competent person. It may be the case that
it is no longer possible to operate the heating
installation after this.
▶Arrange for the competent person to reset
all settings to factory settings.
Menu →Basic settings →Factory reset →Everything
–While the control is resetting the settings to the factory
settings, in process is shown on the display. Then the
installation assistant appears in the display, which only
the competent person may operate.
5.2.12 Installer level
The Installer level is reserved for the competent person and
is therefore protected by an access code. At this operating
level, the competent person can make the necessary set-
tings.