STIEBEL ELTRON LWZ 8 CS Premium User manual

OPERATION
Central ventilation unit with heat recovery / Integral system with air/water heat
pump for central DHW heating and heating
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2 

SPECIAL INFORMATION
OPERATION
1. General information �����������������������������������������3
1.1 Safety instructions����������������������������������������������� 3
1.2 Other symbols in this documentation ����������������������� 3
1.3 Units of measurement ������������������������������������������ 3
2. Safety����������������������������������������������������������3
2.1 Intended use������������������������������������������������������ 3
2.2 General safety instructions ������������������������������������ 3
2.3 Test symbols ������������������������������������������������������ 4
3. Appliance description ���������������������������������������4
4. Operation �����������������������������������������������������4
4.1 Controls������������������������������������������������������������ 4
4.2 Operating modes ������������������������������������������������ 6
4.3 Favourites, quick access, function block �������������������� 7
4.4 Entering parameters �������������������������������������������� 7
4.5 Main menu�������������������������������������������������������� 8
 INFO ���������������������������������������������������������������� 8
 DIAGNOSIS �������������������������������������������������������� 8
 SYSTEM STATUS�������������������������������������������������� 8
 FAULT LIST ��������������������������������������������������������� 8
 PROGRAMS ������������������������������������������������������� 8
 HEATING PROGRAM ��������������������������������������������� 8
 DHW PROGRAM �������������������������������������������������� 9
 FAN PROGRAM ��������������������������������������������������� 9
 HOLIDAY PROGRAM ��������������������������������������������� 9
 PARTY PROGRAM ������������������������������������������������ 9
 SETTINGS��������������������������������������������������������� 10
 HEATING ���������������������������������������������������������� 10
 DHW ��������������������������������������������������������������� 11
 VENTILATION ���������������������������������������������������� 12
 COOLING ���������������������������������������������������������� 12
 SOLAR THERMAL������������������������������������������������ 13
 SCREED DRYING PROG. ���������������������������������������� 14
 COMMISSIONING ������������������������������������������������ 14
 TIME / DATE������������������������������������������������������ 14
 CONTRACTOR ���������������������������������������������������� 14
5. Cleaning, care and maintenance ������������������������� 15
5.1 Replacing supply air and extract air filters���������������� 15
5.2 Replacing the outdoor air filter ������������������������������ 16
5.3 Cleaning the extract and supply air vent filters ���������� 16
6. Troubleshooting �������������������������������������������� 16
6.1 Filter symbols appear������������������������������������������ 16
6.2 No hot water����������������������������������������������������� 16
6.3 The safety valve of the cold water supply line is
dripping ���������������������������������������������������������� 16
6.4 The fault symbol appears ������������������������������������� 16
6.5 The appliance leaks water ������������������������������������ 16
6.6 Condensate on the outside of the appliance or on the
air hoses���������������������������������������������������������� 16
6.7 Noise is emitted������������������������������������������������� 16
6.8 The required flow temperatures are not reached,
particularly during drying out ������������������������������� 17
6.9 The accommodation is always too cold �������������������� 17

- The appliance may be used by children aged8
and older and persons with reduced physical,
sensory or mental capabilities or a lack of ex-
perience and know-how, provided that they are
supervised or they have been instructed on how
to use the appliance safely and have understood
the potential risks. Children must never play with
the appliance. Children must never clean the ap-
pliance or perform user maintenance unless they
are supervised.
6.10 The accommodation is always too hot ��������������������� 17
6.11 The accommodation is too cold in winter������������������ 17
6.12 The accommodation is too hot in winter������������������� 17
6.13 The accommodation is too cold in spring and autumn � 17
6.14 The accommodation is too hot in spring and autumn �� 17
6.15 The accommodation is too hot in summer ���������������� 17
6.16 Air quality is too poor������������������������������������������ 17
6.17 The air in winter is too dry ����������������������������������� 17
7. Menu structure ��������������������������������������������� 18
GUARANTEE
ENVIRONMENT AND RECYCLING



w LWZ 5-8 CS Premium / 3

1. General information
This manual is intended for the appliance user and qualified con-
tractors.
Note
Read these instructions carefully before using the appli-
ance and retain them for future reference.
Pass on the instructions to a new user if required.
1.1 Safety instructions
1.1.1 Structure of safety instructions
KEYWORD Type of risk
Here, possible consequences are listed that may result
from failure to observe the safety instructions.
 Steps to prevent the risk are listed.
1.1.2 Symbols, type of risk
 
Injury
Electrocution
Burns
(burns, scalding)
1.1.3 Keywords
 
DANGER Failure to observe this information will result in serious
injury or death.
WARNING Failure to observe this information may result in serious
injury or death.
CAUTION Failure to observe this information may result in non-seri-
ous or minor injury.
1.2 Other symbols in this documentation
Note
Notes are bordered by horizontal lines above and below
the text. General information is identified by the adjacent
symbol.
 Read these texts carefully.
 
Material losses
(appliance damage, consequential losses and environmen-
tal pollution)
Appliance disposal
 This symbol indicates that you have to do something. The ac-
tion you need to take is described step by step.
These symbols show you the software menu level (in
this example level3).
1.3 Units of measurement
Note
All measurements are given in mm unless stated other-
wise.
2. Safety
2.1 Intended use
The appliance is a complete system with the following functions:
LWZ 8 CS Pre-

CS Premium
LWZ 5 S

LWZ 8 S


LWZ 5 S

Centralised ventilation
with heat recovery
x x x -
Central DHW provision x x x x
DHW cylinder integrated
into the appliance
x x - x
Connection of an external
DHW cylinder
x - x -
Heating x x x x
Cooling x - - -
Connection of thermal
solar collectors
x - - -
The appliance is intended for domestic use. It can be used safely
by untrained persons. The appliance can also be used in non-do-
mestic environments, e.g. in small businesses, as long as it is used
in the same way. Any other use beyond that described shall be
deemed inappropriate. Observation of these instructions is also
part of the correct use of this appliance.
2.2 General safety instructions
The appliance should only be operated once it is fully installed
and all safety equipment has been fitted.
WARNING Electrocution
Never splash the appliance with water or other liquids.
WARNING Burns
There is a risk of scalding at outlet temperatures in ex-
cess of 43°C.
WARNING Injury
The discharged cold air can cause condensation to be
formed in the vicinity of the air discharge.
 Ensure that no risk of slipping due to wet conditions
or ice formation occurs on adjacent footpaths and
driveways at low temperatures.



4 
WARNING Injury
The appliance may be used by children over 8 years of
age and persons with reduced physical, sensory or men-
tal capabilities or a lack of experience and expertise,
provided that they are supervised or they have been
instructed on how to use the appliance safely and have
understood the potential risks. Children must never play
with the appliance. Children must never clean the ap-
pliance or perform user maintenance unless they are
supervised.
Note
Do not change any system-specific settings at the con-
trol unit. Your qualified contractor has set the control
unit to match the local conditions for your building and
your individual requirements. The system-specific para-
meters are protected by a code to prevent unintentional
modifications.
The parameters that serve to adapt the appliance to your
personal requirements are not protected by a code.
Appliances with ventilation function
WARNING Injury
If there is a radio or police announcement ordering win-
dows and doors to be kept closed, simply select fan stage
"0" (= fan off) for several hours.
The programming unit must be activated if the appliance
has been out of operation for a long time:
 Hold down "MENU" button for three seconds.
 If you have already navigated through the menu
tree, pressing MENU will return you to the default
display. If necessary you may have to press menu
several times.
 Slide your finger along the scroll wheel until you
reach the "VENTILATION STAGES" entry.
 Press "OK".
 Press "OK" again to adjust the "Unscheduled vent."
parameter.
 Set the "UNSCHEDULED VENT." parameter to 0 by sli-
ding your finger anti-clockwise over the scroll wheel.
 Confirm with "OK".
 Set the "UNSCHED. VENT TIME STAGE0" parameter
to a suitable value.
Never adjust the setting of supply and extract air valves inside the
rooms. These have been adjusted during commissioning.
2.3 Test symbols
See type plate on the appliance.
3. Appliance description
When there is a heat demand, outdoor air is channelled through
the evaporator and its energy extracted. This energy is boosted
to a higher temperature level by means of the heat pump, to heat
the DHW and the heating system.
When the temperature is very low, or when there is a very high
heat demand, the appliance covers the residual heat demand by
means of an integral electric emergency/booster heater. With a
mono mode design, the electric emergency/booster heater is acti-
vated for emergency heating if the temperature reading falls below
the standard outside temperature, set as the dual mode point.
This ensures heating operation and the provision of high DHW
temperatures. In mono energetic mode, the electric emergency/
booster heater is activated as a booster heater.
The appliance is controlled by a weather-compensated control
unit.
Appliances with ventilation function
Heat is recovered from the extract air via a highly efficient
cross-countercurrent heat exchanger. The cooled air is discharged
outdoors as exhaust air.
Appliances with solar heat exchanger
An additional heat exchanger is included in the common return to
the heat pump. The thermal solar collectors connected can back
up both DHW heating and room heating. A differential tempera-
ture controller for the solar thermal system is integrated in the
appliance control unit.
A heat exchanger built into the outdoor air flow heats the outdoor
air for domestic ventilation. If sufficient solar heat is available, the
outside air is preheated indirectly by solar energy.
Appliances with cooling function
The refrigeration unit of the heat pump may be reversed. In co-
oling mode, heat can then be extracted from the heating circuit
and transferred to the outdoor air.
Inverter
The compressor in the appliance has an electronic speed cont-
roller. The compressor adjusts its output to the cooling/heating
demand. If the current room temperature is far from the set tem-
perature, the provision of cooling/heating output for the room
will be accordingly high. If the temperature differential decreases,
the appliance reacts to the change in requirements and provides
a lower cooling or heating output. This results in advantages of
economy and convenience when compared with appliances wit-
hout inverter technology, where the compressor either runs at
maximum output or is off.
Heat metering
The appliance is equipped with an integral heat meter. In the
„INFO“ menu, the supplied amounts of heat are displayed.
4. Operation
4.1 Controls
The programming unit enables you to change parameters and
to obtain information on the appliance operation. The appliance
can also be controlled when no programming unit is connected
or the connected one is faulty. The programming unit comprises
the scroll wheel, two keys and above these a display.



w LWZ 5-8 CS Premium / 5
4.1.1 Display
26�04�01�0292
WEDNESDAY 10. SEPT 14 10:23 TIME
OUTSIDE TEMPERATURE
DHW TEMPERATURE
27.0 °C
35.0 °C
28.0 °C
FLOW TEMPERATURE
DAY MODE
1
2
3
4
1 Date and time
2 Favourites When you are in the menu, the favourites dis-
play is no longer shown.
3 Operating mode, Quick link, Function block
4 Appliance status symbols
You can adjust the contrast of the display and select the language
of the display texts in the „COMMISSIONING“ menu.
4.1.2 Picture symbols on the display
At the lower edge of the display, symbols provide information
about the current appliance operating status. Up to eight symbols
can be displayed at once.
Filter change, top:
The extract air filter is contaminated. Please change the
extract air filter.
Filter change, bottom:
The supply air filter is contaminated. Please change the
supply air filter.
Filter change, top and bottom:
The filter change service intervals of the extract air and
the supply air filters have expired or the filters have beco-
me contaminated prematurely. Please change the extract
air and supply air filters.
Electric emergency/booster heater:
The electric emergency/booster heater has started up.
This occurs, for example, when the outside temperature
has fallen below the dual mode point.
Cooling:
The cooling symbol is displayed when the appliance is
in heating mode.
Heating:
The heating symbol is displayed when the appliance is
in heating mode.
DHW heating:
This symbol tells you that the appliance is heating DHW.
Compressor:
The compressor symbol signals that the compressor is run-
ning.
Evaporator defrost:
The evaporator is defrosting.
Switching program enabled:
If a switching program is enabled, this symbol is display-
ed.
Service:
A service is required. Please contact your qualified con-
tractor.
Ventilation stage:
For a limited period the appliance operates with a mo-
dified ventilation stage.
Heating circuit pump:
The pump symbol is displayed when a heating circuit
pump is running.
Heat-up:
This symbol shows when the dry heating (screed drying)
program runs.
Power-OFF:
This symbol lights up if the appliance has no enable signal
from the power supply utility.
4.1.3 Scroll wheel
D0000064710
The scroll wheel consists of a touch-sensitive sensor. There is a
key to the left and another to the right of it.
Note
If you have gloves on, have wet hands or the programm-
ing unit is damp, this impedes the recognition of your
touch and the execution of the action you require.
In the „COMMISSIONING“ menu, your qualified contractor can set
the touch sensitivity using the „TOUCH SENSITIVITY“ parameter.
Activation
The user interface is blocked to protect the appliance from acci-
dental incorrect adjustments.
 Touch the menu button for 3 seconds to enable the user
interface.
If the scroll wheel and keys are not used for 20minutes, the pro-
gramming unit is locked again. With the function block, you can
block the user interface for 60 seconds.
Once the programming unit is activated, you have two adjustment
options:
- You can select operating modes with the scroll wheel.
- You can press „MENU“ to continue navigating from there to a
specific appliance parameter.



6 
Selection indicator
As you move through the menu and parameter levels, the selection
indicator shows your current position. Either a dark background
appears or the current list entry is highlighted by two lines, one
above and one below.
Circular movement
If you brush a finger clockwise along the recessed scroll wheel,
the highlighting field moves through the list of parameters either
to the right, or downwards if the parameters are arranged ver-
tically. With an anti-clockwise rotation, the highlighter moves to
the left or upwards.
Alongside navigation within the menu structure, the scroll wheel is
also used to set parameters. If you make a clockwise rotation, the
value is raised. With a circular movement anti-clockwise, values
are reduced.
Faster circular motions increase the step magnitude when chan-
ging parameters. Your qualified contractor can determine at what
speed of rotation the step magnitude changes, in the „COMMIS-
SIONING“ menu using the „TOUCH ACCELERATION“ parameter.
4.1.4 Menu key
If you are on the default screen, press „MENU“ to enter the second
level of the menu structure. There, you have access to the applian-
ce setting options, such as the input of switching time programs.
If you are not in the highest menu level, tap the menu key to go
back one level.
Note
In the following sections of this document, the abbre-
viation "MENU" means you should touch the MENU key.
Note
Tap the keys only briefly to initiate the required action.
If you touch the menu and OK keys for too long, the pro-
gramming unit will not respond.
4.1.5 OK button
With one touch of the OK key, you confirm the selection of the
menu entry highlighted. This brings you into the menu tree on the
next menu level. If you are already at the parameter level, „OK“
saves the currently set parameter.
4.2 Operating modes
When the start screen is activated, the current operating mode
is displayed. If you want to select another operating mode, scroll
with the scroll wheel.
WEDNESDAY 10. SEPT 14 10:23 TIME
OUTSIDE TEMPERATURE
DHW TEMPERATURE
14.0 °C
35.0 °C
18.0 °CROOM TEMPERATURE
DAY MODE
26�04�01�0292
 Operating modes
 STANDBY
 AUTOMATIC
 DAY MODE
 SETBACK MODE
 DHW MODE
 MANUAL MODE
 EMERGENCY MODE
At the end of this selection list, further setting options are avai-
lable:
 FAVOURITES
 VENTILATION STAGES
 HOTTER / COLDER
 FUNCTION BLOCK
4.2.1 STANDBY
In standby mode, the appliance delivers the set standby values.
Generally, you will switch the appliance into minimum operation
with standby mode. The appliance runs in standby mode until
another operating mode is enabled.
4.2.2 AUTOMATIC
In automatic mode, the time programs set for central heating,
DHW and ventilation are implemented. Automatic mode is the
standard appliance setting. The heating flow temperature is re-
gulated according to a weather-compensated heating curve. The
appliance runs in setback mode if no time programs are enabled.
4.2.3 DAY MODE
In day mode (generally while occupants are present in the house,
during the day), the heating system operates with the selected set
day values. Day mode does not influence DHW heating or venti-
lation.
4.2.4 SETBACK MODE
The appliance activity is reduced in setback mode, for example
at night time, or during the day when nobody is at home. In set-
back mode, the heating system is operated with the selected set
night values. Setback mode does not influence DHW heating or
ventilation.



w LWZ 5-8 CS Premium / 7
4.2.5 DHW MODE
DHW mode is enabled in accordance with the set time programs.
For the current pair of switching times, the DHW set day value
is delivered. The central heating is switched off except for frost
protection. DHW operation does not influence ventilation.
4.2.6 MANUAL MODE
If manual mode is enabled, the set values selected for manual
mode are delivered. In manual mode, the heating flow tempera-
ture is not influenced by the outside temperature.
4.2.7 EMERGENCY MODE
If emergency mode is enabled, the „Compressor“ heating stage is
skipped. Heating is provided by the solar thermal system (if con-
nected) or the electric emergency/booster heater. The dual mode
point is not taken into consideration. Using the electric emergency/
booster heater on its own for long periods means high energy
costs. If you activate emergency mode, the set room temperatures
from automatic mode are used. The switching programs from
automatic mode are also used.
In emergency mode, the appliance applies the set temperatures
and switching programs from automatic mode for DHW heating.
4.3 Favourites, quick access, function block
4.3.1 FAVOURITES
Up to three parameters are constantly shown on the display when
the appliance is in operation. To select your favourites, navigate
to the required parameter. If the square at the end of the line is
not filled in, this parameter is not yet one of your favourites. Press
„OK“ to change this. However, you can only select three favourites.
You may therefore have to disable one of your current favourites.
Press „OK“ to disable.
4.3.2 Ventilation stages
26�04�01�0367
UNSCHED. VENT TIME STAGE 2
UNSCHEDULED VENT.
VENTILATION STAGES
02
Under „UNSCHEDULED VENT.“ enter the required value (0 to3).
This setting is valid for a limited time, which you set in the neig-
hbouring menu item, e.g. „UNSCHED. VENT TIME STAGE0“. If
you do not set a time, the appliance adopts the saved parameter
values.
4.3.3 HOTTER / COLDER
Here, you can change the set room temperatures for the heating
circuits and thereby raise or lower the heating curves.
4.3.4 FUNCTION BLOCK
If you select the „FUNCTION BLOCK“ function, the programming
unit will be blocked for 60 seconds. During this time, you can
clean the programming unit without accidentally changing the
appliance settings. A counter appears on the screen that shows
the remaining blocking time in seconds.
4.4 Entering parameters
Parameters are changed by scrolling with the scroll wheel. To
save the new value, touch „OK“. If you want to cancel the entry,
press „MENU“.
Note
If more than five minutes pass without any user activity,
rotation or tapping of "MENU" or "OK", the programm-
ing unit display automatically jumps back to the default
screen. Recent parameter changes not yet been confir-
med with "OK" will be lost. The parameters retain the
values previously saved.
Example 1
To enter set temperatures, a number surrounded by a circle ap-
pears on the display. This indicates that you can change the value
by turning the scroll wheel.
+
21.7
-
MAIN MENU
HEATING
ROOM TEMPERATURE DAY
°C
26�04�01�0347
ROOM TEMPERATURES HC1 HC
ROOM TEMPERATURE DAY
Example 2
To set holiday dates, a calendar page for the selected month ap-
pears.
DAY MONTH YEAR HOUR MINUTE
26�04�01�0300
Settings
HOLIDAY PROGRAM-PARTYHOLIDAY PROGRAM
HOLS BEGINNING
MO TUE WED THU FRI SAT SUN
02 03 04 05 06 07 08
09 10 11 12 13 14 15
16 17 18 19 20 21 22
23 24 25 26 27 28 29
01
30
Turning the scroll wheel displays the highlighter that you can then
move to the required date.



8 
Example 3
Some parameters are selected via highlighted boxes. The positions
where the box is highlighted, i.e. coloured in black, are active. One
example is setting up favourites. With „OK“ you can highlight the
box, or remove it if the item was already highlighted. For favouri-
tes, up to three highlighted list entries can be selected in this way.
ROOM TEMPERATURE HC1
SET ROOM TEMPERATURE HC1
ROOM TEMPERATURE HC2
SET ROOM TEMPERATURE HC2
34.2 °C
26�04�01�0298
MAIN MENU
INFO ROOM TEMPERATURE
4.4.1 Contractor access
To prevent incorrect adjustments, some appliance parameters may
only be changed by qualified contractors. These parameters are
protected and can only be changed after entering a code.
0* **
26�04�01�0293
ENTER CODE
MAIN MENU
SETTINGSDHWSTANDARD SETTING
BOOSTER TIMEOUT
4.5 Main menu
Note
Some menu items are protected by a code and can only
be accessed and adjusted by a qualified contractor.
26�04�01�0294
INFO
MAIN MENU
DIAGNOSIS
PROGRAMS
SETTINGS
CONTR ACTOR
 INFO
In the „INFO“ menu, actual values are displayed. See the chapter
„Menu structure“ for a list of these.
 DIAGNOSIS
 SYSTEM STATUS
POWER-OFF POWER-OFF indicates whether voltage is pre-
sent at the power supply utility input. If voltage
is present, the power supply utility has not
disabled any component of the appliance.
STOVE / FIREPLACE
AIR HEAT EXCH. DEFR.
EVAPORATOR DEFROST
 FAULT LIST
The fault memory contains the ten most recent fault messages. The
display, however, can show only six fault messages at a time. Turn
the scroll wheel to access the other entries in the fault memory.
 PROGRAMS
If automatic mode is set, this is where you define the time pro-
grams that control the appliance.
 HEATING PROGRAM
HEATING CIRCUIT 1| HEATING CIRCUIT 2
You can set individual heating programs for heating circuits 1
and 2. This determines when and how often the appliance should
operate in day mode. At all other times, the appliance operates in
setback mode. You can select the set values for day and setback
mode under the menu item „ROOM TEMPERATURES“.
First, select the days on which you want to enable the heating
function:
+
-
26�04�01�0301
MONDAY
MO
MAIN MENU
PROGRAMS
HEATING PROGRAM HC
HEATING CIRCUIT 1
- on individual days („MONDAY“, ... , „SUNDAY“)
- from Monday to Friday („MON - FRI“)
- on Saturday and Sunday („SAT - SUN“)
- throughout the whole week („MON - SUN“)
Monday is initially offered.
 Select the day or a group of days.
 Confirm your selection with „OK“.
You can now set three switching time pairs. The three switching
time pairs are shown on the display, to the right of the clock. A
switching time pair comprises the start time and end point, at
which the appliance returns to its previous state.



w LWZ 5-8 CS Premium / 9
07:00 - 20:00
- -:- - - - -:- -
- -:- - - - -:- -
26�04�01�0299
MONDAY
MAIN MENU
PROGRAMS
HEATING PROGRAM HC
HEATING CIRCUIT 1
In this example, only one switching time pair has so far been
programmed. For switching time pairs 2 and 3, short dashes are
displayed instead of times. These switching time pairs are still
empty. Select one of the free switching time pairs with „OK“ to
reach the area where you can set the associated start and end
time. Pressing „OK“ brings up the display shown below. Set the
required time.
END
- -:- - - -:- -
TIME TIME
START
26�04�01�0302
MAIN MENU
PROGRAMS
HEATING PROGRAM HC
SETTINGS
Times can be entered in intervals of 15 minutes. Confirm your
entry with OK.
Periods around midnight
Assume, for example, you want heating mode to be enabled from
22:00h for four hours every Wednesday evening. However, since
the day ends at 00:00h, two switching time pairs are necessary for
the required program. First, program the period 22:00 to 00:00h
for Wednesday, then 00:00 to 02:00h for Thursday.
Deleting a switching times pair
Select the pair of switching times you want to delete. Go to the
start time change. Turn the scroll wheel to reduce the time. If you
reach 00:00 and continue to make a rotation, the pair of switching
times is removed. The previously shown display appears, i.e. das-
hes instead of numbers. Confirm again with OK.
 DHW PROGRAM
Here, you can set the periods when DHW is heated with reference
to the set day temperatures. In the other phases, the set night
temperatures are followed. You can select the set values for day
and night mode as described in the DHW chapter.
Example: You want to heat up DHW daily at two different times, i.e.
from 22:00 to 05:00h the following day, and then again from 08:00
to 11:00h. Since the day begins at 00:00h, begin programming
at 00:00h. The first pair of switching times runs from 00:00 to
05:00h. The second pair of switching times starts at 08:00h and
ends at 11:00h. The third switching time pair runs from 22:00 to
24:00h.
The pairs of switching times should be selected so that the DHW
cylinder can be completely heated up between the start and stop
times (at least 3 hours).
 FAN PROGRAM
The setting is made as for the central heating and DHW programs.
 HOLIDAY PROGRAM
During the holidays, if nobody is in the house, central heating,
DHW and ventilation are not required in their full scope. All set
temperatures are set to match the set values of the standby func-
tion. Define the first and last days of the holiday. At the end of the
holiday, the appliance runs according to the set programs again.
HOLS BEGINNING
DAY
MONTH
YEAR
HOUR
MINUTE
HOLIDAYS ENDING
DAY
MONTH
YEAR
HOUR
MINUTE
 PARTY PROGRAM
Under this parameter you can extend day mode for several hours.
Enter the start and end time of your party. Times can be set that
go beyond the end of the day the party starts.



10 
 SETTINGS
 HEATING
Two heating circuits can be operated with this appliance, e.g. one
direct heating circuit for radiator heating system and one heating
circuit with mixer for underfloor heating system.
Enter the „ROOM TEMPERATURES HC1“ submenu for settings ap-
plicable to the first heating circuit.
ROOM TEMPERATURES HC1
ROOM TEMPERATURE DAY HC1
ROOM TEMP. NIGHT HC1
ROOM TEMP. STANDBY HC1
MANUAL SET HC1
ROOM TEMPERATURE HC1
Select the required set room temperature for day, setback and
standby modes.
MANUAL SET HC: Under this parameter, set the heating flow tem-
perature for manual mode.
ROOM TEMPERATURE: This parameter, the display of the current
value, is only shown if a room temperature sensor is connected.
ROOM TEMPERATURES HC2
See chapter „ROOM TEMPERATURES HC1“. Set the values in this
submenu accordingly.
HEATING CURVE HC1
GRADIENT HC1
LOW END HC1
ROOM INFLUENCE HC1
FLOW PROPORTION HC1
MAX. SET VALUE HC1
MIN. SET VALUE HC1
HEATING CURVE HC1
The room temperature will only remain constant irrespective of
the outside temperature if the correct heating curve has been
selected for the relevant type of building. Selecting the correct
heating curve is therefore vitally important. The more precisely
the heating curve is set, the more economically the appliance
works. Try therefore to optimise your heating curve. Reduce the
current heating curve until the flow temperature is just sufficient
for heating. The target is as flat a heating curve as possible.
 Fully open thermostatic valves (remove head) in a lead room,
for example living room or bathroom.
 At different outside temperatures, adjust the heating curve so
the required temperature is set in the lead room (living room
or bathroom). Now the room temperature in these rooms is
controlled with the heating curve (see next diagram).
Standard values to begin with:
 



GRADIENT 0.4 0.8
LOW END K 3 10
ROOM TEMPERATURE DAY °C 20 20
1
3
2
4
5
∆Y
∆X
D0000051930
X Outside temperature [°C]
Y Heating circuit temperature sensor [°C]
1 Gradient influence
Gradient = ΔY/ΔX
= Heating circuit temperature change/Outside temperature
change
2 Low end offset influence
3 Heating curve
4 Set room temperature influence
5 Low end
GRADIENT
With the „GRADIENT“ parameter, you can set the extent to which
a change in the outside temperature causes a rise in the flow tem-
perature. Typical problem: Increase the gradient if the room tem-
perature is too low at low outside temperatures (approx. -10°C).
LOW END
By changing the „LOW END“ parameter, you cause a parallel offset
of the heating curve. Typical applications are explained in the
chapter „Troubleshooting“.
ROOM INFLUENCE
If you want to influence the heating curve through the room tem-
perature, install an auxiliary „FESComfort“ programming unit in
your home. As the underfloor heating system has a delayed effect
on the room temperature, this can be counteracted via additional
heating such as solar irradiation or a fireplace. You must enter a
value > 0 for the „ROOM INFLUENCE“ parameter.
Set heating circuit temperature= set heating circuit temperature
from heating curve+ ((set room temperature- actual room tem-
perature)* room influence* gradient/ 10)



w LWZ 5-8 CS Premium / 11
FLOW PROPORTION
Flow means the pipework that supplies hot water to the heating
system. The return carries the cooled water from the heating sys-
tem to the heating system. With the „FLOW PROPORTION“ para-
meter you determine whether your heating system should function
as a flow or return temperature-controlled system.
   
0Return temperature control 0 100
30 30 70
50 50 50
80 80 20
100 Flow temperature control 100 0
You should normally set values below 50 (we recommend 30) for
heating circuit 1, to restrict the influence of the flow temperature.
Particularly in spring and autumn, the flow temperature is subject
to naturally strong fluctuations because of the heat pump being
switched on and off. If these strong fluctuations make it necessary,
the booster stages would also be started, although the heat pump
alone would be capable of covering the current heat demand.
No flow proportion is scanned for heating circuit2. Always enter
100 here, as the mixer circuit does not have its own return sensor.
MIN. SET VALUE/ MAX. SET VALUE
With these parameters, you set the minimum and maximum set
temperatures for the heating circuit. These values limit the hea-
ting curve in the upper and lower regions. Even if the calculated
heating curve would go beyond these limits, it is limited to these
set values.
HEATING CURVE
Under this parameter, you can display the heating curves for both
heating circuits.
60
40
50
30
20
10
00
-25 -20 -15 -10 -05 00 05 10 15 20 25
26�04�01�0348
MAIN MENU
HEATINGHEATING CURVE HC1
HEATING CURVE
HC TEMPERATURE °C
TA
°C
Note that parameter „FLOW PROPORTION“ has an influence on
heating curve „HC1“. This means the heating curve is distinctly
lower than the flow temperature curve. (see examples 1 and 2).
The heating curve for „HC2“ is a flow temperature curve.
Example 1
Heating curve 55/40, Radiator heating system
Set room temperature °C 20
Low end °C 5
Gradient  0.65
Flow proportion %30
Design temperature °C -15
0
10
20
30
40
50
60
-15 -10 -5 0 5 10 15 20
1
3
2
26�04�01�0379
X Outside temperature [°C]
Y Heating temperature [°C]
1 Flow
2 Heating curve
3 Return
Example 2
Heating curve 35/28, Underfloor heating
Set room temperature °C 20
Low end °C 1
Gradient 0.3
Flow proportion %30
Design temperature °C -15
0
5
10
15
20
25
30
35
40
-15 -10 -5 0 5 10 15 20
1
3
2
26�04�01�0380
X Outside temperature [°C]
Y Heating temperature [°C]
1 Flow
2 Heating curve
3 Return
If you have set the heating curve successfully, set the thermostatic
valves to the required temperature.
Note
Never reduce the temperature in the entire building by
closing all thermostatic valves. Instead, use the night
programs or select the set room temperature with the
"HOTTER/ COLDER" parameter.
STANDARD SETTING
These parameters are reserved for qualified contractors and are
described in the installation instructions.
 DHW
DHW TEMPERATURES
DHW SET DAY
DHW SET NIGHT
DHW SET STANDBY
DHW SET MANUAL
DHW TEMPERATURE



12 
Select the set DHW temperatures here. Enter the values for day,
setback, standby and manual modes. Subject to operating mode,
the temperature in the DHW cylinder is brought to the correspon-
ding set value. The current water temperature in the cylinder is
shown under „DHW TEMPERATURE“.
MIXED WATER AMOUNT
For this appliance, this menu displays no parameters other than
the actual value „MIXED WATER AMOUNT“. The amount of mixed
water indicated does not relate to any second DHW cylinder that
may be connected.
STANDARD SETTING
These parameters are reserved for qualified contractors and are
described in the installation instructions.
 VENTILATION
Here, you can set the parameters for the centralised ventilation
of your home.
VENTILATION STAGES
DAY STAGE
NIGHT STAGE
STANDBY STAGE
PARTY STAGE
MANUAL STAGE
VENTILATION TIMES
UNSCHED. VENT TIME STAGE 0
UNSCHED. VENT TIME STAGE 1
UNSCHED. VENT TIME STAGE 2
UNSCHED. VENT TIME STAGE 3
VENTILATION STAGES

Ventilation
for humidity
protection
0 Necessary ventilation for ensuring that the building
structure is protected under normal conditions of use
with somewhat reduced moisture loads, e.g. during
temporary absence of users and no drying of washing in
the residential unit.
Reduced
ventilation
1 Ventilation necessary to meet minimum hygiene stan-
dards and ensure protection of the building structure
(humidity) under normal conditions of use with partially
reduced humidity and pollutant loads, e.g. as a result of
intermittent user absence.
Standard
ventilation
2 Ventilation necessary to meet hygiene standards and
ensure protection of the building structure when users
are present (standard mode).
Intensive
ventilation
3 Ventilation necessary from time to time, with a higher
air flow rate to reduce load peaks. For intensive ven-
tilation, it can be assumed that the user will assist (by
manually opening windows for a time).
VENTILATION TIMES
Normally, the appliance controls when and for how long to venti-
late. However, via the quick access option „VENTILATION STAGES“
you can run ventilation outside the normal schedule.
Under „UNSCHED. VENT TIMESTAGE 1“ determine for how many
minutes the fan should run, if you set the appliance to stage1 via
parameter „VENTILATION STAGES“. Specify the ventilation times
for stages 0, 2 and 3 accordingly.
The selected ventilation stage will not be enabled for 20 seconds.
Quick ventilation with external pushbutton
With an external pushbutton that can be installed on site, you
can set ventilation immediately to stage3. Ventilation runs with
stage 3 and will only switch off after the time set in parameter
„UNSCHED. VENT TIMESTAGE 3“.
Humidity protection ventilation (stage 0)
The control unit includes a humidity protection ventilation func-
tion. This is provided to protect against humidity damage, if ven-
tilation is not required. This could be, for example, during pro-
longed absence due to holidays. For this, in the „VENTILATION/
PARAMETER“ menu, the humidity protection parameter must be
set to „ON“. The humidity protection ventilation is activated after
a pause of 24 hours. Ventilation is inactive prior to the expiry of
the 24 hour period.
Ventilation starts if the relative humidity inside the room exceeds
a limit whilst ventilation is switched off (stage 0). Ventilation is
switched off again if the limit is undershot by more than the selec-
ted hysteresis. The limit is dependent on the outside temperature.
 Please consult your qualified contractor.
Fan output correction (stage1/2/3) subject to humidity
For output stages 1, 2 and 3, the qualified contractor can activate a
correction subject to humidity. This is made subject to the relative
humidity in the room. At low levels of relative humidity, such as
in winter, for example, the air flow rate will be reduced subject to
the output reduction parameter. This counteracts excessive drying
out. In summer, the humidity-dependent fan output correction can
reduce excessive humidity levels in rooms.
 Please consult your qualified contractor.
SERVICE
„RUNTIME FILTER:“: This parameter indicates when the last filter
reset was carried out.
„RESET FILTER“: This parameter enables you to carry out a filter
reset by selecting „ON“.
 COOLING
The FESComfort digital remote control is equipped with a tempe-
rature sensor as well as a humidity sensor that is used to monitor
the dew point in area heating systems (such as underfloor heating
systems, wall area heating systems, chilled ceilings).
Active cooling
If the heating circuit temperature is greater than the set hea-
ting circuit temperature, and the „COOLING MODE“ parameter
is enabled, the compressor and defrost valve switch on and the
hydraulics are controlled externally. For cooling mode to function
via area heating systems, cooling thermostats and control valves
must be used and connected to the „Cool“ port in the appliance
control panel.



w LWZ 5-8 CS Premium / 13
Cooling and DHW heating
Cooling mode is interrupted as soon as a DHW demand is issued,
and DHW heating commences.
Cooling and solar
Under parameter „SOLAR“ qualified contractors can use parame-
ter „PRIORITY SOLAR“ to select the priority for cooling operation if
a solar thermal system is connected. Possible settings are „Priority
solar“, „Priority cooling“ and the time-controlled setting via „Prio-
rity cooling time“. This programs the period for cooling. If „Priority
solar“ has been selected, cooling will not be enabled for as long
as the solar starting conditions are met and the maximum system
temperatures have not been reached. With „Priority cooling“, the
solar overload function and collector protection are disabled. The
solar start conditions are checked as soon as cooling ends.
 Enable cooling mode for the required heating circuits by set-
ting parameter „COOLING MODE“ („OFF“/ „ON“).
ROOM TEMPERATURES HC1
ROOM TEMPERATURE DAY HC1
ROOM TEMP. NIGHT HC1
ROOM TEMP. STANDBY HC1
ROOM TEMPERATURE HC1
To allow the appliance to cool, you must set the „COOLING MODE“
parameter to the value „ON“. Refer to your qualified contractor for
the required adjustments.
Cooling is enabled when the appliance is in summer mode and the
outside temperature exceeds the set room temperature for heating
by 3K for 2hours. If the room temperature is then higher than the
set room temperature for cooling by the amount set in the „HYST.
ROOM TEMP.“ parameter, cooling will be prepared. The display
shows a snowflake. The circulation pump starts, the three-way
valve changes over to the heating circuit and the „cooling“ output
is activated in order to, for example, open the thermostatic valves
in the rooms to be cooled.
By selecting a set room temperature you can influence when the
appliance starts its cooling operation.
ROOM TEMPERATURES HC2
See chapter „ROOM TEMPERATURES HC1“.
COOLING MODE HC1
COOLING MODE HC1 OFF | ON
COOLING SYSTEM HC1 AREA COOLING| FAN
COOLING
Code-protected
HC TEMP. COOLING HC1 Code-protected
HYST. ROOM TEMP. HC1 Code-protected
COOLING MODE HC2
See chapter „COOLING MODE HC1“.
 SOLAR THERMAL
SOLAR ACTIVATION OFF | ON
TEMP. DIFFERENTIAL
DHW COMPRESSOR DELAY
DHW SOLAR TEMP.
If you have connected a solar thermal system, you will find all the
parameters here which have to be specified for solar mode. In
solar mode, the appliance is backed up by the solar heat exchanger
for DHW heating and central heating.
SOLAR ACTIVATION
If you want to enable solar mode, set the value in parameter
„SOLAR ACTIVATION“ to 1.
TEMP. DIFFERENTIAL
With the aid of this parameter, also known as solar differential
temperature, you define a temperature that is used as the thres-
hold for starting and stopping the solar circuit pump.
The solar circuit pump starts if the collector temperature is hig-
her than the return temperature by the „TEMP. DIFFERENTIAL“ +
„SOLAR HYSTERESIS“. The solar circuit pump stops if the collector
temperature is only „TEMP. DIFFERENTIAL“ – „SOLAR HYSTERESIS“
above the return temperature. The parameter „SOLAR HYSTERE-
SIS“ is set by the qualified contractor.
Ensure that the stop point is not below the return temperature.
That can be the case if the hysteresis has been set above the tem-
perature differential. The greater the value of the solar differential
temperature, the later the solar circuit pump starts when the sun
comes out. At the same time, the risk of heat loss from the cylin-
der is reduced. If heat were lost from the cylinder, the thermal
energy would flow in the opposite direction, i.e. water that had
already been heated would be cooled down because insolation
was still too low.
DHW COMPRESSOR DELAY
When the solar circuit pump runs, the compressor is blocked for
the period defined here. DHW is only heated with solar energy
during this time.
DHW SOLAR TEMP.
If the DHW cylinder has been heated up, the set flow temperature
has been reached and the collector temperature remains high,
the DHW cylinder can be heated up to a higher temperature to
store solar energy.
Set the temperature to which the DHW cylinder should be heated
here.
WARNING Burns
Parameter "DHW SOLAR TEMP." should only be set higher
than 60°C if suitable measures have been taken to provi-
de protection against scalding. There is a risk of scalding
at outlet temperatures in excess of 43°C.
If you want to use the solar function, your qualified contractor
should set the following values:
MINIMUM CYCLES 1
MAXIMUM CYCLES ≥50
OUTSIDE TEMP MAX CYC °C 0
OUTSIDE TEMP MIN CYC °C 25

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14 
 SCREED DRYING PROG.
The dry heating (screed drying) program is not necessary for daily
requirements. The explanation can be found in the installation
instructions for qualified contractors.
 COMMISSIONING
PROGRAMMING UNIT
CONTROL UNIT SOFTWARE
The programming unit‘s software version is displayed here.
CONTRAST
With the „CONTRAST“ parameter, you can set the contrast between
the characters shown on the display and the display background.
BRIGHTNESS
LANGUAGE
Here you can select the language in which the display texts are
shown.
ROOM TEMP CORRECTION
If the room temperature captured by the programming unit does
not correspond with the actual room temperature, for example if
the sensor is mounted on a cold external wall, you can make a cor-
rection at the appliance. In the parameter „ROOM TEMP CORREC-
TION“, enter the difference between the actual room temperature
and the room temperature displayed on the programming unit.
Example:
Actual temperature °C 19
Displayed temperature °C 21
New parameter value -2
REL HUMIDITY CORRECTION
If the relative humidity in the room as measured on the pro-
gramming unit does not correspond to the real relative humidity
in the room, you can make a correction on the appliance. If the
value displayed by the programming unit is too low, increase the
value set under parameter „REL HUMIDITY CORRECTION“.
CONTROLLER
SOFTWARE VERSION
„SOFTWARE VERSION“ shows which software version is installed
on the control PCB. The software version indicates the appliance
type.
SOFTWARE ID
„SOFTWARE ID“ shows the consecutive number of the software.
 TIME / DATE
TIME / DATE
In the „TIME/ DATE“ menu, enter the current time and date, so
the appliance can start the time programs you enter at the correct
time. Position the selection indicator over the position „YEAR“ and
confirm with „OK“. Set the current year and confirm with „OK“.
Set the month accordingly. To help you set the „Day“, a calendar
page appears. Move the highlighter to the required day. The new
value is saved when you confirm with „OK“.
SUMMERTIME MANUAL
Under the „SUMMERTIME MANUAL“ menu item, you can set the
period for summertime.
SUMMERTIME AUTOMATIC
Instead of entering the time period for summer mode manually,
you can select the summertime specified at the factory. For this,
set the „SUMMERTIME AUTOMATIC“ menu item to „ON“.
 CONTRACTOR
The parameters in the „CONTRACTOR“ menu have a great influen-
ce on the appliance control properties, and are therefore protected
with a password to prevent incorrect settings. As an appliance
user, you can see these parameters, but if you jump to the next
menu level, you meet the code check.
FAULT SEARCH
If the appliance registers a fault, this is clearly displayed with the
message shown below.
!FAULT
CODE NO. 001
PLS INFORM CUST SERVICE
WEDNESDAY 10. SEPT 14 16:27 TIME
26�04�01�0303
If more than one fault occurs, the most recent fault is always
shown. Please inform your qualified contractor. To see the usual
default display, first enable the programming unit by pressing
„MENU“ for 5seconds. The fault message is then extended with
a note requesting that you acknowledge the fault by pressing OK
for five seconds.
FAULT LIST
The fault list contains the ten most recent fault messages. The
display, however, can show only six fault messages at a time. Scroll
with the scroll wheel to access the other entries in the fault list.
PROCESS VALUES
These values are used for analysis in the event of a fault.



w LWZ 5-8 CS Premium / 15
PROCESS STATUS
These values are used for analysis in the event of a fault.
ANALYSIS
In the „ANALYSIS“ submenu actual values are displayed that may
be useful to the service department when troubleshooting.
INVERTER
These values are used for analysis in the event of a fault.
5. Cleaning, care and maintenance
Note
Keep the air intake and discharge apertures on the exte-
rior wall free from snow and leaves.
 Check the supply air and extract air filters regularly for
contamination.
5.1 Replacing supply air and extract air filters
Note
This chapter is only relevant for appliances with venti-
lation function.
 Hold down „MENU“ button for three seconds.
 If you have already navigated through the menu tree, pres-
sing MENU will return you to the default display. If necessary
you may have to press menu several times.
 Use the scroll wheel to navigate to the „VENTILATION
STAGES“ entry.
 Press „OK“.
 Press „OK“ again to adjust the „Unscheduled vent.“
parameter.
 Set the „UNSCHEDULED VENT.“ parameter to 0.
 Confirm with OK.
 Set the „UNSCHED. VENT TIMESTAGE 0“ parameter to a sui-
table value, e.g. 30minutes.
A door lock is located above the door.
 Push the door lock at the front upwards.
 Pull the door lock backwards and then upwards to unhook
the door lock.
26�04�01�0545
 Open the door carefully.
2.
3.
4.
1.
26�04�01�0544
1
2
1 Extract air filter
2 Supply air filter
 Undo the r.h. knurled nut by turning it anti-clockwise.
 Loosen the left knurled nut by turning it anti-clockwise so
that you can carefully pivot the filter cover aside.
 Pull out the filter cassette.
Note
Ensure that you do not interchange the extract air and
supply air filters when reinserting them into the applian-
ce. The filter cassette of the extract air filter (upper filter)
features two grip holes at the front.
Note
Ensure that the direction of air flow through the filter is
correct.
1
D0000093656
1 Direction of flow

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
16 
 101
The more coarsely porous, blue
side is the air intake side of the
filter.
The direction of flow is indicated by an
arrow on the side of the filter.
 Replace the filter.
 Push the new filter cassette into the appliance.
 Rotate the filter cover back into its original position and then
tighten the r.h. knurled nut clockwise.
 Tighten the l.h. knurled nut.
 At the programming unit, activate the „RESET FILTER“ para-
meter („SETTINGS/ VENTILATION/ SERVICE“).
WARNING Injury
All other work on the appliance must only be carried out
by qualified contractors.
Note
Have the cross-countercurrent heat exchanger, outdoor
air filter, evaporator and fans checked and (if required)
cleaned once a year by a qualified contractor.
5.2 Replacing the outdoor air filter
The outdoor air filter is fitted downstream of the cross-counter-
current heat exchanger. The outdoor air filter must be replaced
by a qualified contractor.
5.3 Cleaning the extract and supply air vent filters
 If installed, clean the extract air vent filters through which air
is extracted from the rooms.
 If installed, clean the supply air vent filters through which air
is supplied to the rooms.
 Clean the filter box (if present) attached to the outdoor air
connector on the rear of the appliance.
6. Troubleshooting
6.1 Filter symbols appear
The appliance is equipped with an automatic filter contamination
detector. The constant flow rate control of the fans results in an
increase in fan speed when the filters become contaminated. This
increase in speed is evaluated to display a filter change require-
ment.
When the filters are contaminated, the following symbols are di-
splayed.
Filter change, top:
The extract air filter is contaminated. Please change the
extract air filter.
Filter change, bottom:
The supply air filter is contaminated. Please change the
supply air filter.
Filter change, top and bottom:
Extract air and supply air filters are contaminated or their
filter change intervals have expired. Please change the
extract air and supply air filters.
The filter symbol appears automatically after three months.
6.2 No hot water
Should you fail to obtain hot water, you can take the following
steps to remedy the situation yourself:
- If the appliance has no power: Check the fuse/circuit breaker
in your fuse box. If it has blown/tripped, replace/reset the
fuse/MCB. Notify your qualified contractor if the fuse/MCB
blows/trips again.
- If the appliance has power: Check whether the air intake/
discharge is blocked. Check whether a fault code is being
displayed, and if necessary, notify your qualified contractor.
Check whether the control unit is set correctly.
6.3 The safety valve of the cold water supply line
is dripping
This may occur during the heat-up phase and is completely nor-
mal.
6.4 The fault symbol appears
Note If this symbol appears, it means a fault has occurred.
Notify your qualified contractor or call customer service.
6.5 The appliance leaks water
If water escapes from the appliance, shut it down immediately and
notify your qualified contractor.
6.6 Condensate on the outside of the appliance or
on the air hoses
In the drying out phase or when relative humidity is high (>60%),
it is normal for condensate to appear on the surface of the appli-
ance and on the thermally insulated air hoses. This should stop
when the house has dried out thoroughly which, subject to the
design, can take up to 2 years. If the room is used to dry washing
however, condensate can still form.
 Check whether the air hoses are fitted correctly, and that no
cold air escapes.
6.7 Noise is emitted
Since the appliance moves very large volumes of air, it cannot
work silently.
However, there should not be any disturbing noises in the living
rooms and bedrooms. To achieve this, ensure that
- the appliance has been installed correctly.
- the installation room has a door that closes tightly.
- adequately sized silencers are integrated directly on the ap-
pliance in the supply air and extract air ducts.
- additional silencers are installed between bedrooms, nurse-
ries and living rooms.



w LWZ 5-8 CS Premium / 17
- the air volumes have been adjusted and checked according to
the system design.
If you notice dragging noises when the fan or heat pump are in
operation, take the appliance out of use immediately and notify
your qualified contractor.
If dragging noises occur during heat pump operation, the exhaust
air fan may be the cause. During shipping, the fan may slightly
move in relation to the air nozzle. This may result in dragging
noises. If necessary, the exhaust air fan should be aligned as part
of the commissioning work.
Contamination of the outdoor air filter can lead to higher noise
emissions. The outdoor air filter is fitted downstream of the
cross-countercurrent heat exchanger. The outdoor air filter must
be replaced by a qualified contractor.
6.8 The required flow temperatures are not
reached, particularly during drying out
When drying screed, output levels will be required that are far
above those necessary for standard heating operation. It can the-
refore take a relatively long time before, for example, the low end
temperature is reached. However, the correct temperature curve
for drying out is ensured because the next stage in every case is
not started until the default temperature for the current step has
been reached. In case of all other faults, please always notify your
qualified contractor.
6.9 The accommodation is always too cold
Increase the low end temperature of the heating curve. Raise the
temperature by the number of degrees you require to obtain a
comfortable temperature.
6.10 The accommodation is always too hot
Reduce the low end temperature of the heating curve by the
number of degrees the room temperature exceeds a comfortable
temperature.
6.11 The accommodation is too cold in winter
If the temperature of your home in spring and autumn is OK,
but the rooms do not become warm enough when the outside
temperature drops sharply (-10°C), increase the gradient of the
heating curve. This means it will become slightly warmer in spring
and autumn. You should therefore slightly lower the low end tem-
perature.
Another reason might be the dual mode point. Increasing the
dual mode point, however, can lead to high energy consumption.
If sound-reduced night mode is activated, in rare cases there may
not be enough heating output available at low outside tempera-
tures. Change the value of the „DUAL MODE POINT“ parameter.
6.12 The accommodation is too hot in winter
If your heating system produces too much heat when temperatures
drop sharply, reduce the gradient of the heating curve. This means
your home will become slightly colder in spring and autumn. You
should therefore slightly raise the low end temperature.
6.13 The accommodation is too cold in spring and
autumn
One possible cause may be that summer mode is enabled and that
central heating is off, as a result. Switch the appliance to manual
mode or ask your qualified contractor to change the standard
settings.
If the room temperature in spring and autumn (10°C) is too low,
reduce the gradient and increase the low end temperature.
6.14 The accommodation is too hot in spring and
autumn
 Increase the heating curve gradient slightly and reduce its
low end slightly.
6.15 The accommodation is too hot in summer
Stop summer mode and activate passive cooling, if required.
6.16 Air quality is too poor
 Select a higher fan stage.
6.17 The air in winter is too dry
 Select fan stage 1.
 Activate the humidity correction.
When going away, switch the appliance to reduced ventilation.
You can set a fan program for this. Here you set the time during
which the appliance runs in day mode. For the rest of the time,
the appliance runs at the fan stage that you set in the „NIGHT
STAGE“ parameter.
If you cannot remedy the fault, notify your qualified contractor.
To facilitate and speed up your request, provide the number from
the type plate (000000-0000-000000).
1
D0000075599
1 Type plate



18 
7. Menu structure
Note
Some menu items are protected by a code and can only
be accessed and adjusted by a qualified contractor.
Note
Subject to appliance type, not all appliance parameters
and values are displayed in the different menus.
  
 INFO
 ROOM TEMPERATURE
ROOM TEMPERATURE HC1 °C If an external programming unit is connected and assigned to the heating circuit, the temperature mea-
sured in the programming unit is displayed. If the heating circuit has no programming unit assigned,
the actual set room temperature is displayed as a substitute value.
SET ROOM TEMPERATURE HC1 °C
RELATIVE HUMIDITY HC1 % If an external programming unit is connected and assigned to the heating circuit, the humidity measu-
red in the programming unit is displayed. If the heating circuit has no programming unit assigned, 0%
is displayed.
ROOM TEMPERATURE HC2 °C If an external programming unit is connected and assigned to the heating circuit, the temperature mea-
sured in the programming unit is displayed. If the heating circuit has no programming unit assigned,
the actual set room temperature is displayed as a substitute value.
SET ROOM TEMPERATURE HC2 °C
RELATIVE HUMIDITY HC2 % If an external programming unit is connected and assigned to the heating circuit, the humidity measu-
red in the programming unit is displayed. If the heating circuit has no programming unit assigned, 0%
is displayed.
 HEATING
OUTSIDE TEMPERATURE °C
ACTUAL VALUE HC1 °C Heating circuit temperature, calculated from the flow and return temperatures, weighted with the value
set under "FLOW PROPORTION". Whilst DHW is being heated, this parameter indicates the temperature
with which the DHW cylinder is being heated.
SET VALUE HC1 °C Default temperature for the heating circuit
ACTUAL VALUE HC2 °C
SET VALUE HC2 °C
FLOW TEMPERATURE °C The flow is the heating pipework between heat pump and heat consumer (radiator or indirect coil inside
the DHW cylinder). Here you can see the temperature of the water in this pipe section.
RETURN TEMPERATURE °C The return is the heating pipework between heat consumer and the heat pump. Here you can see the
temperature of the water in this pipe section.
PRESSURE HTG CIRC bar
FLOW RATE l/min
 DHW
DHW TEMPERATURE °C Shows the current cylinder water temperature
DHW 2 ACT. TEMP. °C If the „2ND DHW CYLINDER“ parameter is set to „ON“, the temperature in the second DHW cylinder is
shown here.
DHW SET TEMPERATURE °C
CYLINDER TOP TEMPERATURE °C
MIXED WATER AMOUNT l
 VENTILATION
SUPPLY AIR ACTUAL Hz Indicates the current supply air fan speed.
SUPPLY AIR SET m³/h This value indicates the percentage of maximum control voltage with which the supply air fan operates.
Supply air is the heated outdoor air that is blown into the ventilation area (living room, bedroom, nur-
sery).
EXTRACT AIR ACTUAL Hz Current speed of the extract air fan
EXTRACT AIR SET m³/h This value indicates the percentage of maximum control voltage with which the extract air fan operates.
Extract air is the stale air that is extracted from the extract air area (bathroom, kitchen, WC).
EXTRACT AIR HUMIDITY %
EXTRACT AIR TEMP. °C
EXTRACT AIR DEW POINT °C
DIFFERENTIAL PRESSURE ACTUAL Pa If the „FAN CONTROL“ parameter is set to „DIFFERENTIAL PRESSURE“, the differential pressure between
the extract air and the atmospheric pressure in the installation room is shown here.
 COOLING
DEW POINT TEMP. HC1 °C
DEW POINT TEMP. HC2 °C
 SOLAR THERMAL



w LWZ 5-8 CS Premium / 19
  
COLLECTOR TEMP. °C Temperature of the solar collector
 HEAT GENERATOR
HEATING STAGE
 HEAT PUMP
HOT GAS TEMPERATURE °C This value specifies the temperature of the gaseous refrigerant at the condenser inlet.
HIGH PRESSURE bar
LOW PRESSURE bar
EVAPORATOR TEMP. °C In the evaporator, the refrigerant is evaporated at low pressure. As this happens, heat is extracted from
the air flow.
CONDENSER TEMP. °C In the condenser, the refrigerant is liquefied at high pressure. This releases heat which is transferred to
the heating medium.
OIL SUMP TEMPERATURE °C
EXHAUST AIR ACTUAL Hz Current speed of the exhaust air fan
EXHAUST AIR SET Set flow rate of the heat pump fan
DIFF. PRESSURE EVAP. Pa
COMPRESSOR STARTS
 AMOUNT OF HEAT
HEAT METER HTG DAY kWh Amount of heat that was transferred by the heat pump to the heating circuit on this day.
HEAT METER HTG TTL MWh Amount of heat that has been transferred by the heat pump to the heating circuit since the appliance
was commissioned.
HEAT METER DHW DAY kWh Amount of heat that was transferred by the heat pump to the DHW cylinder on this day.
HEAT METER DHW TTL MWh Amount of heat that has been transferred by the heat pump to the DHW cylinder since the appliance was
commissioned.
HEAT M BOOST HTG TTL MWh Amount of heat that has been transferred by the electric emergency/booster heater to the heating circuit
since the appliance was commissioned
HEAT M BOOST DHW TTL MWh Amount of heat that has been transferred by the electric emergency/booster heater to the DHW cylinder
since the appliance was commissioned
HEAT M RECOVERY DAY kWh Amount of heat that was recovered from the ventilation system on this day.
HEAT M RECOVERY TTL MWh Amount of heat that has been recovered from the ventilation system since the appliance was commis-
sioned.
HM SOLAR HTG DAY kWh Amount of heat that was transferred by the solar thermal system to the heating circuit on this day.
HM SOLAR HTG TOTAL MWh Amount of heat that has been transferred by the solar thermal system to the heating circuit since the
appliance was commissioned.
HM SOLAR DHW DAY kWh Amount of heat that was transferred by the solar thermal system to the DHW cylinder on this day.
HM SOLAR DHW TOTAL MWh Amount of heat that has been transferred by the solar thermal system to the DHW cylinder since the
appliance was commissioned.
HM COOLING TOTAL MWh Amount of heat absorbed by the appliance via its evaporator from the rooms.
 RUNTIMES Here, the runtime of some appliance components since appliance commissioning is shown.
COMPRESSOR HEATING h
COMPRESSOR COOLING h
COMPRESSOR DHW h
ELEC BOOSTER HEATING h
ELEC BOOSTER DHW h
 POWER CONSUMPTION
PWR CON HTG DAY kWh Power drawn by the compressor on this day for supplying the heating circuit.
PWR CON HTG TTL MWh Power drawn by the compressor since commissioning for supplying the heating circuit
PWR CON DHW DAY kWh Power drawn by the compressor on this day for supplying the DHW cylinder
PWR CON DHW TTL MWh Power drawn by the compressor since commissioning for supplying the DHW cylinder
 DIAGNOSIS
 SYSTEM STATUS
POWER-OFF
STOVE / FIREPLACE
AIR HEAT EXCH. DEFR.
EVAPORATOR DEFROST
SILENTMODE Status of sound-reduced night mode (1 = active, 0 = inactive)
SOLAR Status of the solar circuit pump (1 = active, 0 = inactive)
SUMMER MODE Here, the display shows whether the appliance is in summer mode (1 = summer mode).
 FAULT LIST



20 
      
 PROGRAMS
 HEATING PROGRAM    
HEATING CIRCUIT 1
MONDAY Time period1| Time period2| Time period3
TUESDAY Time period1| Time period2| Time period3
WEDNESDAY Time period1| Time period2| Time period3
THURSDAY Time period1| Time period2| Time period3
FRIDAY Time period1| Time period2| Time period3
SATURDAY Time period1| Time period2| Time period3
SUNDAY Time period1| Time period2| Time period3
MON - FRI Time period1| Time period2| Time period3
SAT - SUN Time period1| Time period2| Time period3
MON - SUN Time period1| Time period2| Time period3
HEATING CIRCUIT 2 See HEATING CIRCUIT 1
 DHW PROGRAM See HEATING CIRCUIT 1
 FAN PROGRAM See HEATING CIRCUIT 1
 HOLIDAY PROGRAM
HOLS BEGINNING
DAY 1 31 1
MONTH 1 12 1
YEAR 0 99 11
HOUR 0 23
MINUTE 0 59
HOLIDAYS ENDING
DAY 1 31 1
MONTH 1 12 1
YEAR 0 99 11
HOUR 0 23 0
MINUTE 0 59
 PARTY PROGRAM
START 00:00 23:45
END 00:00 23:45
 STANDARD SETTING
MAX. ADVANCE min 0300 0
 SETTINGS
 HEATING
ROOM TEMPERATURES HC1
ROOM TEMPERATURE DAY HC1 °C 10 30 21
ROOM TEMP. NIGHT HC1 °C 10 30 21
ROOM TEMP. STANDBY HC1 °C 10 30 10
MANUAL SET HC1 °C 10 65 35
ROOM TEMPERATURE HC1 °C
ROOM TEMPERATURES HC2
ROOM TEMPERATURE DAY HC2 °C 10 30 21
ROOM TEMP. NIGHT HC2 °C 10 30 21
ROOM TEMP. STANDBY HC2 °C 10 30 10
MANUAL SET HC2 °C 10 65 35
ROOM TEMPERATURE HC2 °C
HEATING CURVE HC1
GRADIENT HC1 0 5 0.3
LOW END HC1 °C 020 3
ROOM INFLUENCE HC1 0 100 0
FLOW PROPORTION HC1 0 100 30
MAX. SET VALUE HC1 °C 10 65 55
MIN. SET VALUE HC1 °C 040 10
HEATING CURVE HC1
HEATING CURVE HC2
GRADIENT HC2 0 5 0.3
LOW END HC2 °C 020 3
ROOM INFLUENCE HC2 0 100 0
MAX. SET VALUE HC2 °C 10 65 55
MIN. SET VALUE HC2 °C 040 10
HEATING CURVE HC2
STANDARD SETTING
PRO P. COMP. %/K 0 10 2