STIEBEL ELTRON WWK 220 electronic Instruction Manual

OPERATION AND INSTALLATION
OBSŁUGA I INSTALACJA
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CONTENTS
SPECIAL INFORMATION
OPERATION
1. General information �����������������������������������������4
1.1 Safety instructions����������������������������������������������� 4
1.2 Other symbols in this documentation ����������������������� 4
1.3 Units of measurement ������������������������������������������ 4
1.4 Standardised output data�������������������������������������� 4
2. Safety����������������������������������������������������������4
2.1 Intended use������������������������������������������������������ 4
2.2 Incorrect use������������������������������������������������������ 5
2.3 General safety instructions ������������������������������������ 5
2.4 CE designation ��������������������������������������������������� 5
2.5 Test symbols ������������������������������������������������������ 5
3. Appliance description ���������������������������������������5
3.1 Heating the DHW cylinder ������������������������������������� 6
3.2 Appliance operation outside the application limits������� 6
3.3 Frost protection �������������������������������������������������� 6
4. Settings �������������������������������������������������������7
4.1 Display and controls��������������������������������������������� 7
4.2 Settings ������������������������������������������������������������ 7
4.3 Calling up fault codes ������������������������������������������� 9
4.4 Rapid heating key ����������������������������������������������� 9
4.5 Emergency shutdown������������������������������������������� 9
5. Maintenance and care ������������������������������������� 10
6. Troubleshooting �������������������������������������������� 10
INSTALLATION
7. Safety�������������������������������������������������������� 12
7.1 General safety instructions ����������������������������������� 12
7.2 Instructions, standards and regulations ������������������� 12
8. Appliance description ������������������������������������� 12
8.1 Standard delivery����������������������������������������������� 12
8.2 Required accessories ������������������������������������������ 12
8.3 Further accessories��������������������������������������������� 12
8.4 Incorrect use����������������������������������������������������� 12
9. Preparations������������������������������������������������ 12
9.1 Transport ��������������������������������������������������������� 12
9.2 Storage������������������������������������������������������������ 13
9.3 Installation site�������������������������������������������������� 13
9.4 Siting the appliance �������������������������������������������� 14
10. Installation�������������������������������������������������� 15
10.1 Water connection ����������������������������������������������� 15
10.2 Connection of an external heat generator (only
WWK300electronicSOL) ������������������������������������� 15
10.3 Condensate drain ����������������������������������������������� 16
10.4 Power supply ���������������������������������������������������� 16
10.5 Assembling the appliance ������������������������������������ 17
11. Commissioning ��������������������������������������������� 17
11.1 Commissioning�������������������������������������������������� 17
11.2 Recommissioning����������������������������������������������� 18
12. Shutting down���������������������������������������������� 18
13. Troubleshooting �������������������������������������������� 18
13.1 Fault table�������������������������������������������������������� 19
13.2 Resetting the safety pressure limiter ����������������������� 19
13.3 Resetting the high limit safety cut-out ��������������������� 19
13.4 Motor overload relay������������������������������������������� 19
14. Maintenance and cleaning �������������������������������� 19
14.1 Removing the appliance cover ������������������������������� 19
14.2 Removing the casing ring������������������������������������� 20
14.3 Cleaning the evaporator��������������������������������������� 20
14.4 Draining the cylinder ������������������������������������������ 20
14.5 Descaling the electric emergency/booster heater ������� 21
14.6 Protective anode ������������������������������������������������ 21
14.7 Valves ������������������������������������������������������������� 21
14.8 Replacing the power cable ����������������������������������� 21
14.9 Fitting the casing ring ����������������������������������������� 21
14.10 Fitting the appliance cover ����������������������������������� 21
15. Specification ������������������������������������������������ 22
15.1 Dimensions and connections��������������������������������� 22
15.2 Wiring diagram ������������������������������������������������� 25
15.3 Data table �������������������������������������������������������� 26

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ENGLISH
SPECIAL INFORMATION
SPECIAL INFORMATION
- The appliance may be used by children aged8
and up and persons with reduced physical, sen-
sory or mental capabilities or a lack of experience
and know-how, provided that they are supervised
or they have been instructed on how to use the
appliance safely and have understood the result-
ing risks. Children must never play with the ap-
pliance. Children must never clean the appliance
or perform user maintenance unless they are
supervised.
- Observe all applicable national and regional reg-
ulations and instructions during installation.
- The appliance is not approved for outdoor
installation.
- Observe the minimum clearances (see chap-
ter "Installation/ Preparations/ Siting the
appliance").
- Observe the requirements concerning the instal-
lation room (see chapter "Specification/ Data
table").
- If the appliance is permanently connected to the
power supply, ensure that the appliance can be
separated from the power supply by an isolator
that disconnects omnipolar with at least 3mm
contact separation. Contactors, mains isolators or
fuses can be used for this.
- Observe the safety measures to prevent contact
with dangerous 'live' currents.
- Observe the MCB/fuse protection required for
the appliance (see chapter "Specification/ Data
table").
- The power cable must only be replaced (for ex-
ample if damaged) with an original spare part by
a qualified contractor authorised by the manufac-
turer (connection typeX).
- The appliance is pressurised. During the heat-up
process, expansion water will drip from the safety
valve.
- Regularly activate the safety valve to prevent
it from becoming blocked, e.g. by limescale
deposits.
- Drain the appliance as described in chapter "In-
stallation/ Maintenance and cleaning/ Draining
the cylinder".
- Install a type-tested safety valve in the cold water
supply line.
- The maximum pressure in the cold water supply
line must be at least 20% below the response
pressure the safety valve. If the maximum pres-
sure in the cold water supply line is higher, install
a pressure reducing valve.
- Size the drain so that water can drain off unim-
peded when the safety valve is fully opened.
- Fit the discharge pipe of the safety valve with
a constant downward slope and in a room free
from the risk of frost.
- The safety valve discharge aperture must remain
open to atmosphere.

OPERATION
General information
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OPERATION
1. General information
The chapters “Special information” and "Operation" are intended
for appliance users and qualified contractors.
The chapter "Installation" is intended for qualified contractors.
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
Symbol Type of risk
Injury
Electrocution
Burns
(burns, scalding)
1.1.3 Keywords
KEYWORD Meaning
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
General information is identified by the symbol shown
on the left.
 Read these texts carefully.
Symbol Meaning
Material losses
(appliance damage and consequential losses, 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.
1.3 Units of measurement
Note
All measurements are given in mm unless stated oth-
erwise.
1.4 Standardised output data
Explanations to determine and interpret the specified standardised
output data
Standard: EN 16147
The output data specifically mentioned in text, diagrams and
technical datasheets has been determined in line with the test
conditions described in the standard shown in the heading of
this chapter.
Generally, these standardised test conditions will not fully meet
the conditions found at the installation site of the system user.
Depending on the chosen test method and the extent to which
the selected method deviates from the conditions described in the
standard shown in the heading of this chapter, any deviations can
have a considerable impact. Further factors that have an influence
on the test values are the measuring equipment, the system con-
figuration, the age of the system and the flow rates.
A confirmation of the specified output data can only be obtained
if the conditions applicable to the relevant test match those of the
standard shown in the heading of this chapter.
2. Safety
2.1 Intended use
The appliance is intended for DHW heating within the application
limits detailed in chapter "Specification/ Data table".
The appliance is intended for domestic use, i.e. it can be used
safely by untrained persons. The appliance can also be used in a
non-domestic environment, e.g. in a small business, as long as it
is used in the same way.
Any other use beyond that described shall be deemed inappropri-
ate. Observation of these instructions and of instructions for any
accessories used is also part of the correct use of this appliance.
!
!

OPERATION
Appliance description
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ENGLISH
2.2 Incorrect use
The following are not permitted:
- Heating liquids other than potable water
- Operating the appliance with an empty DHW cylinder
- Operating the appliance outside the application limits (see
chapter "Specification")
- Interrupting the power supply, as without power supply the
appliance is not protected against corrosion
2.3 General safety instructions
Only qualified contractors should carry out the electrical work and
installation of this appliance. Qualified contractors are responsible
for adherence to all applicable regulations.
Operate the appliance only when fully installed and with all safety
equipment fitted.
!
WARNING Injury
The appliance may be used by children aged 8 and up and
persons with reduced physical, sensory or mental capa-
bilities or a lack of experience and know-how, provided
that they are supervised or they have been instructed on
how to use the appliance safely and have understood
the resulting risks. Children must never play with the
appliance. Children must never clean the appliance or
perform user maintenance unless they are supervised.
WARNING Electrocution
Contact with live components presents a threat to life.
Damage to the insulation or to individual components
may result in a threat to life.
 If there is damage to the insulation, disconnect the
power supply and arrange a repair.
All work on the electrical installation must be carried
out by a qualified contractor.
WARNING Scalding
The water in the DHW cylinder can be heated to temper-
atures in excess of 60°C. There is a risk of scalding at
outlet temperatures in excess of 43°C.
 Ensure you do not come into contact with the water
when discharged.
WARNING Burns
Touching hot components can lead to burns.
When working on hot components, always wear protec-
tive working clothing and safety gloves.
The pipework connected to the DHW outlet of the appli-
ance can reach temperatures in excess of 60°C.
WARNING Scalding
The appliance is filled with refrigerant at the factory.
In the event of refrigerant escaping due to a leak, avoid
coming into contact with the refrigerant or inhaling the
released vapours. Ventilate the rooms affected.
!
CAUTION Injury
Never place any objects on top of the appliance. If objects
are left on the appliance, noise emissions may increase
due to resulting vibrations, and the objects could fall
and cause injury.
!
Material losses
If you disconnect the appliance from the power supply, it
is no longer protected against frost.
 Do not interrupt the power supply to the appliance.
!
Material losses
Never cover this appliance. Covering the air intake or air
discharge leads to a reduced air supply. If the air supply
is restricted, the operational reliability of the appliance
cannot be guaranteed.
!
Material losses
Only operate the appliance when the DHW cylinder has
been filled.
!
Material losses
Keep the appliance installation room free from air con-
taminated with oil or salt and corrosive or explosive sub-
stances.
2.4 CE designation
The CE designation shows that the appliance meets all essential
requirements according to the:
- Electromagnetic Compatibility Directive
- Low Voltage Directive
2.5 Test symbols
See type plate on the appliance.
3. Appliance description
The appliance is designed for indoor installation. The appliance
operates in recirculation air mode and does not require outdoor
air. The appliance extracts heat from the ambient air. This heat is
used to heat up the water in the DHW cylinder with added electric
power. The amount of electric energy and time required to heat-up
the DHW depend on the temperature of the induced air.
This heat extraction results in a drop in the ambient tempera-
ture inside the installation room by between 1°Cand3°C. The
appliance also extracts moisture from the air, which turns into
condensate. The condensate is removed from the appliance via
the condensate drain.
When a hot water draw-off point is opened, the hot DHW is pushed
out of the appliance by the in-flow of cold DHW.
To protect against corrosion, the DHW cylinder is coated inter-
nally with special enamel and is additionally equipped with an
impressed current anode.
The electronic control unit makes energy saving adjustments easi-
er. Subject to the power supply and your usage pattern, the water
is heated up automatically to the set temperature.

OPERATION
Appliance description
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Heat pump operating principle
A closed circuit within the appliance contains refrigerant (see
"Specification/ Data table"). This refrigerant evaporates at low
temperatures.
In the evaporator, which extracts heat from the air, the refrigerant
changes from its liquid into its gaseous state. A compressor draws
in the gaseous refrigerant and compresses it. This increase in
pressure raises the refrigerant temperature.
That requires electrical energy. The energy (motor heat) is not
lost, but reaches the downstream condenser together with the
compressed refrigerant. There, the refrigerant indirectly transfers
heat to the DHW cylinder. An expansion valve then reduces the
still prevalent pressure and the cycle starts again.
!
Material losses
If you disconnect the appliance from the power supply, it
is no longer protected against frost.
 Do not interrupt the power supply to the appliance.
Note
Following an interruption of the power supply, the
compressor operation remains blocked for at least one
minute. The PCB delays electronic starting by a minute,
during which the appliance goes through its initialising
process.
If the compressor subsequently fails to start, it may be
blocked by additional safety devices (Klixon and high
pressure switch). This block should lift after 1 to 10min-
utes.
After the power supply has been re-established, the ap-
pliance continues to operate with the parameters that
were selected before the power supply was interrupted.
3.1 Heating the DHW cylinder
The water is heated by the appliance heat pump. This is the ap-
pliance's standard mode of operation.
An integral sensor captures the amount of heat in the DHW cylin-
der. The water in the DHW cylinder is heated up if the amount of
heat is lower than that required to achieve the set temperature.
For information on the heat-up time of the water in the DHW
cylinder, see chapter "Specification".
3.1.1 Electric emergency/booster heater
The electric emergency/booster heater is used for rapid/comfort
heating and in emergency mode.
In the event of an unexpectedly high hot water demand, the emer-
gency/booster heater can be activated with the rapid heating key.
See chapter "Rapid/comfort heating".
In the event of an appliance fault, emergency mode can be used
to activate the electric emergency/booster heater. See chapter
"Emergency mode".
3.1.2 Connection of an external heat generator (only
WWK300electronicSOL)
!
Material losses
Even if an external heat generator is connected, do not
disconnect the appliance from the power supply as oth-
erwise it is not protected against frost and corrosion. The
power supply must not be interrupted even in winter,
when it is possible that DHW heating is only being pro-
vided via the external heat generator.
The appliance is equipped with an integral smooth tube heat ex-
changer to which an external heat generator can be connected
(e.g. a solar thermal system or central heating system). The DHW
cylinder has sensor wells available for this in various positions. The
qualified contractor must match the controls once during commis-
sioning between the appliance and the external heat generator.
3.2 Appliance operation outside the application
limits
3.2.1 Ambient temperatures below the application limit
At temperatures below the lower application limit hoar frost may
form on the evaporator depending on the air humidity and water
temperature. If hoar frost forms on the evaporator, the hoar frost
temperature monitor switches the heat pump compressor off. The
compressor switches on automatically once the evaporator has
defrosted.
 To guarantee fault-free operation of the appliance, make sure
you operate the appliance within its application limits (see
chapter "Specification / Data table").
Note
Heat-up times are longer while the evaporator is defrost-
ing.
3.2.2 Ambient temperatures above the application limit
The safety equipment switches the appliance off if the upper ap-
plication limit is exceeded.
Following a cooling time of several minutes the appliance is
switched back on automatically. The appliance is switched off
again if the ambient temperature rises above the permissible tem-
perature value again.
 To guarantee fault-free operation of the appliance, make sure
you operate the appliance within its application limits (see
chapter "Specification / Data table").
3.3 Frost protection
The appliance activates the frost protection function if the integral
sensor in the DHW cylinder captures a temperature below 10°C.
The appliance then heats the water by means of the heat pump
and the electric emergency/booster heater. The heat pump and
electric emergency/booster heater switch off when the tempera-
ture captured by the integral sensor reaches 18°C.

OPERATION
Settings
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ENGLISH
4. Settings
4.1 Display and controls
Note
15seconds after every adjustment, the appliance au-
tomatically reverts to the standard display (amount of
mixed water) and saves the set value.
elctronic comfort
1
3
5
12
10
8
26�03�13�0006�
4
2
7
6
11
9
1 Set temperature symbol
2 Amount of amount of mixed waterdisplay (l|40°C)/
Actual temperature display, upper cylinder section/
Set temperature1display
Set temperature2display
Fault code display
3 Plus key
4 Minus key
5 Service/fault symbol
6 Electric emergency/booster heater symbol
7 Heat pump symbol
8 Rapid heating key
9 Set temperature2 symbol
10 Menu key
11 Amount of amount of mixed watersymbol
12 Actual temperature symbol
The "electric emergency/booster heater" and "heat pump" sym-
bols are displayed when there is a demand for these appliance
components. The display of these symbols does not necessarily
mean that the electric emergency/booster heater and the heat
pump are running.
Example: The appliance is in rapid/comfort heating mode. The
electric emergency/booster heater switches off when the temper-
ature in the upper cylinder section has reached 65°C. The heat
pump has not yet heated the lower section to 65°C and the rapid/
comfort heating function has therefore not been terminated yet.
The electric emergency/booster heater symbol is displayed until
the rapid/comfort heating function has been terminated.
Service/fault symbol
Note
Notify your contractor if the service/fault symbol appears
on the display. Continuous illumination of the symbol
indicates that the fault is not preventing appliance op-
eration.
A flashing service/fault symbol indicates that the water is
not being heated and that it is essential you notify your
contractor.
Switching the appliance to emergency mode is a special
case. The heat pump and the electric emergency/boost-
er heater will then heat the water despite the flashing
service/fault symbol.
4.2 Settings
In standard display mode, the display shows amount of mixed
water.
Note
15seconds after every adjustment, the appliance auto-
matically switches back to standard display and saves
the set value.
With the menu key, you call up all infor-
mation and setting options in sequence.
The relevant symbol appears.
4.2.1 Amount of mixed water display (standard display)
The currently available amount of mixed
water at 40°C and at 15°C cold water
temperature is shown.
If there is currently less than 10l mixed
water available, "<10l" is shown.
DHW demand for Amount of mixed water at 40°C
Bath 120-150 l
Shower 30-50 l
Hand washing 2-5l
The amount of mixed water that can be achieved depends on the
cylinder size and the selected set temperature.

OPERATION
Settings
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4.2.2 Actual temperature display
In the mixed water menu, press the
menu key once to get to the actual tem-
perature menu.
The actual temperature symbol appears.
The current actual temperature is shown.
The actual temperature indicates the
temperature in the upper section of the
DHW cylinder and therefore largely cor-
responds to the outlet temperature.
4.2.3 Set temperature1
Note
For reasons of hygiene, never set the DHW temperature
lower than 50°C.
The set temperature1 is the DHW temperature to which the appli-
ance regulates if no external signal transmitter is connected and
active. Set temperature1 is set to 55°C at the factory.
In the actual temperature menu, press
the menu key once to get to the menu
for set temperature1.
The set temperature1 symbol appears.
Adjust set temperature1 from 20 to 65°C
using the plus and minus keys.
Note
Another way to adjust set temperature1 is to press the
plus or minus key when in standard display (amount of
mixed water).
Frost protection
Only frost protection remains active if
you set the set temperature with the
minus key to less than 20°C.
4.2.4 Set temperature2
Note
For reasons of hygiene, never set the DHW temperature
lower than 50°C.
Set temperature2 is the DHW temperature to which the appliance
regulates if an external signal transmitter is connected and active.
In the set temperature1 menu, press the
menu key once to get to the menu for set
temperature2.
The set temperature2 symbol appears.
The display of set temperature2 is de-
noted with an "N".
Adjust set temperature2 from 20 to 65°C
using the plus and minus keys.
Operation with external signal transmitter (230 V input)
As standard, the appliances feature the ability to allocate a spe-
cific, individual set DHW temperature (set temperature2) to a
connected external signal transmitter, such as a PV system or a
low tariff transmitter.
This set temperature2 is activated when a phase (LF signal) is
present at terminal X0/LF (see chapter "Connection types"). While
activated, set temperature2 replaces the standard set DHW tem-
perature ("set temperature1").
If set temperature2 has been activated by the external signal
transmitter, this set temperature will then be active for at least
20minutes. If the signal remains active after those 20minutes
have passed, the compressor will run until the LF signal ends. If
not, the selected set temperature1 is activated again.
When the relevant set DHW temperature has been reached, the
compressor switches off and remains off for a minimum idle time
of 20minutes.
The following diagram illustrates the connections by means of a
sample signal sequence of an external signal transmitter.
Example:
- DHW temperature = 55°C
- Set temperature 1 = 50°C
- Set temperature 2 = 65°C
A
1
0
0510 15 20 25 30 35 40 45 50 55 60 65 70 75 t [min]
B
1
1
0 2
0510 15 20 25 30 35 40 45 50 55 60 65 70 75 t [min]
D0000034613
A LF signal
B Compressor
1 20 min. minimum runtime, set temperature 2
2 20 min. minimum compressor idle time
Note
An LF signal must be active for at least 60seconds, be-
fore the control unit responds to it. This will for example
prevent a brief burst of sunshine from triggering a heat-
up process, which due to a lack of further insolation can
then not be supplied with PV power generated on site.

OPERATION
Settings
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ENGLISH
4.3 Calling up fault codes
In the set temperature2 menu, press the
menu key once to get to the fault code
menu. A fault code will appear if a fault
has occurred. This menu remains inac-
tive if no fault has occurred.
See chapter "Troubleshooting/ Fault codes".
4.4 Rapid heating key
Press the rapid heating key.
The heat pump and electric emergency/
booster heater symbols appear.
4.4.1 Rapid/comfort heating
Normally, the rapid heating key is used to activate the rapid/com-
fort heating function, which enables you to cover an unexpect-
edly high DHW demand without changing any of the appliance's
standard settings.
If rapid/comfort heating is activated manually by pressing the rele-
vant key, the heat pump and the electric emergency/booster heater
will start in parallel, irrespective of the selected set temperature,
and will remain active until the DHW temperature in the cylinder
has reached 65°C. To save energy, the electric emergency/booster
heater switches off early, as soon as a temperature of 65°C has
been achieved in the upper cylinder section (rapid heating).
The rapid/comfort heating function remains active until a tem-
perature of 65°C has been achieved in the entire DHW cylinder
(comfort heating). The appliance then automatically switches back
to the previously set parameters.
Note
The electric emergency/booster heater and heat pump
symbols are displayed until the rapid/comfort heating
function has terminated.
During rapid/comfort heating, the electric emergency/
booster heater symbol is displayed until the heat pump
has heated the entire cylinder to 65°C and the function
is terminated. The electric emergency/booster heater al-
ready switches off when the 65°C has been achieved in
the upper cylinder section.
Note
If the rapid/comfort heating has been activated uninten-
tionally, you can cancel the function by lowering the set
temperature.
 Hold down the minus key, until you hear a clicking
noise caused by the heat pump and emergency/
booster heater switching off. At the same time, the
set temperature also jumps back to the value that
was selected before rapid/comfort heating was ac-
tivated.
4.4.2 Emergency mode
If the appliance is faulty, you can use the emergency mode to
activate the electric emergency/booster heater.
The compressor shuts down if, following a DHW demand, no tem-
perature increase is captured for 6 hours (24 intervals of 15min-
utes each, during which the temperature increase is <0.25°C re-
spectively). The fault key flashes on the display and a fault code
indicates that the appliance is not heating the water.
In such an event you can activate emergency mode by press-
ing the rapid heating key. After the rapid heating key has been
pressed, the indicated fault code increases by a value of 256, as
the fault codes are added together (see fault code table in chapter
"Troubleshooting"). The fault key continues to flash. The electric
emergency/booster heater is activated.
The current set temperature (set temperature1 or set tempera-
ture2) is ignored. In emergency mode, the appliance operates
with a fixed set temperature of 40°C. Following a one-off activa-
tion of the function via the rapid heating key, this function remains
active for 7days.
Following 7days of emergency operation the electric emergency/
booster heater is deactivated. The fault code shown on the display
decreases by 256.
If you press the rapid heating key again within the 7days of emer-
gency operation, the 7-day runtime for emergency mode will start
afresh from that point.
If the 7-day runtime for emergency mode has passed, you can
restart emergency operation for a further 7days by pressing the
rapid heating key.
Pressing the rapid heating key only activates emergency mode if
a fault with fault code8 occurred previously. In standard mode
pressing the rapid heating key only triggers a one-off heating of
the DHW cylinder.
Emergency mode is no longer active after an interruption of the
power supply. The appliance tries to heat with the heat pump
again. Fault code8 is only set after 6hours. Only then can emer-
gency mode be manually activated again via the rapid heating key.
4.5 Emergency shutdown
In the event of an emergency, carry out the following steps:
 Interrupt the power supply by unplugging the appliance from
the mains or by tripping the MCB.
 Shut off the cold water supply.
 Immediately notify a qualified contractor, as the appliance
is not protected against corrosion while the power supply is
interrupted.

OPERATION
Maintenance and care
10 | WWK 220-300 electronic www.stiebel-eltron.com
5. Maintenance and care
WARNING Electrocution
Only clean the exterior of the appliance.
Never open the appliance.
Do not insert objects through the grille into the interior
of the appliance.
Never spray the appliance with water.
Never spray water into the appliance.
!
WARNING Injury
Maintenance work, such as checking the electrical safe-
ty, must only be carried out by a qualified contractor.
Appliance compo-
nents
Care and maintenance tips
Casing Use a damp cloth to clean the casing sections. Never
use abrasive or corrosive cleaning agents.
Air intake grille / air
discharge grille
Clean the air intake grille and air discharge grille
every six months. Cobwebs or other kinds of contami-
nation can restrict the air supply to the appliance.
DHW cylinder The DHW cylinder is equipped with a mainte-
nance-free impressed current anode to safeguard
it against corrosion. The power supply must not be
interrupted while the appliance is filled with water to
enable the impressed current anode to provide pro-
tection. Otherwise there is a risk of corrosion.
Electric emergency/
booster heater
Have the electric emergency/booster heater descaled
from time to time. This will extend the service life of
the electric emergency/booster heater.
Appliance Have the safety assembly and the evaporator checked
regularly by a qualified contractor.
Condensate drain Undo the condensate drain. Check that the condensate
drain is clear and remove any dirt from the conden-
sate drain connection of the appliance.
6. Troubleshooting
Problem Cause Remedy
No hot water is
available.
No power to the appli-
ance.
Check that the appliance
is connected to the power
supply.
A fuse/MCB in the fuse
box has blown/respond-
ed.
Check whether the fuses/
MCBs in your fuse box have
blown/responded. If required,
disconnect the appliance from
the power supply and replace
the fuses/reset the MCBs.
Contact your contractor if the
fuse blows again after the
appliance is connected to the
power supply.
The air intake or air dis-
charge of the appliance is
blocked.
Check the air intake grille
and air discharge grille for
contamination. Remove any
contamination (see chapter
"Maintenance and care").
The ambient temperature
exceeds the upper appli-
cation limit (see chapter
"Specification/ Data
table"). The appliance
safety equipment has
responded and the ap-
pliance has switched off
automatically.
Wait for the appliance to cool
down. Call a qualified con-
tractor if the appliance does
not switch back on automat-
ically.
Problem Cause Remedy
The ambient temperature
falls below the lower ap-
plication limit (see chap-
ter "Specification/ Data
table"). The evaporator is
currently being defrosted.
Wait until the appliance
switches back on automati-
cally.
The appliance is
not heating the
DHW cylinder
although the heat
pump symbol is
illuminated.
The blocking time for
compressor has not
yet elapsed. Once the
compressor has been
switched off, it will only
be switched back on
again after the 20minute
compressor blocking time
has elapsed.
The safety valve
of the cold water
supply line is drip-
ping.
These units are under
water mains pressure.
During the heat-up pro-
cess, expansion water will
drip from the safety valve.
Notify a qualified contractor if
water continues to drip when
heating is completed.
The condensate
drain drips.
The surface temperature
of the evaporator is lower
than the dew point tem-
perature of the ambient
air. Condensate forms.
The amount of condensate
depends on the air humidity
level.
The room temper-
ature drops too
low.
Operation of the appliance can
cause the room temperature
to fall by 1 to 3°C. If the room
temperature falls by more
than 5°C, check the room size
(see chapter "Specification/
Data table"). Increasing the
room size by opening a door
to another room will remedy
this.
Service/fault sym-
bol is continuously
illuminated.
See chapter "Fault codes". Notify a qualified contractor.
Service/fault sym-
bol flashes and
the water does not
heat up.
See chapter "Fault codes". It is imperative that you notify
a qualified contractor.
The “heat pump”
symbol is flashing.
There is a heat demand,
but the compressor is
blocked.
No action required. The
compressor switches itself
on automatically after the
compressor blocking time
has elapsed. The compressor
blocking time lasts 20minutes
once the compressor has been
switched off. The symbol stops
flashing automatically.
The “electric
emergency/boost-
er heater” symbol
is flashing.
A temperature control-
ler has switched off the
“electric emergency/
booster heater” during
quick heat-up.
No action required. The ap-
pliance continues the quick
heat-up process using the
heat pump. The symbol stops
flashing when the controller
releases the “electric emer-
gency/booster heater”. The
symbol goes out when the
temperature throughout the
DHW cylinder reaches the set
temperature of 65°C.

OPERATION
Troubleshooting
www.stiebel-eltron.com WWK 220-300 electronic | 11
ENGLISH
Fault code
If the service/fault symbol is flashing or continuously illuminated
on the display, you can call up a fault code.
Repeatedly press the menu key until the
fault code is shown following set tem-
perature2.
Fault code appears
Fault
code
Service/
fault
symbol
Fault description Remedy
0 No fault
2 continu-
ously illu-
minated
Dome sensor faulty. The actual
temperature display switches
over to the integral sensor. The
appliance continues to deliver
heat. The amount of mixed
water shown is always less
than 10 litres.
4 continu-
ously illu-
minated
Integral sensor faulty. In the
event of a faulty integral sen-
sor, the integral sensor is set
to the dome sensor value and
amount of mixed water is cal-
culated using this value. The
appliance continues to deliver
heat.
6 flashing Dome sensor and integral
sensor faulty. The appliance no
longer delivers heat.
8 flashing The appliance has ascertained
that the DHW cylinder has not
been heated for 13 hours, de-
spite there being a demand.
You can continue to
use the appliance by
activating emergency
mode. See chapter
"Emergency mode".
16 continu-
ously illu-
minated
Short circuit impressed current
anode / protective anode faulty
Immediately notify a
qualified contractor,
as the appliance is not
protected against cor-
rosion if the impressed
current anode is faulty.
32 flashing
The appliance is operating with
an empty cylinder or the appli-
ance is not delivering heat.
Fill the appliance. The
fault code disappears
and the appliance
starts.
The anode current is inter-
rupted. The appliance does not
heat up.
The contractor needs
to check the impressed
current anode and the
wiring.
128 continu-
ously illu-
minated
No communication between
controller and programming
unit. The most recently selected
set values are active.
256 flashing Manually activated emergency
mode (only electric emergency/
booster heater active).
See chapter "Appliance
description/ Emergen-
cy mode".
If several faults occur, the fault codes are added up.
Example: If both the dome sensor and integral sensor are faulty,
the display shows fault code6(=2+4).
Application scenarios for emergency mode
If the appliance shows fault code8, you can manually activate
emergency mode. If a different fault occurred previously, but did
not cause the appliance to switch off, the display may show a fault
code that is the result of several faults added together.
Listed below are the fault codes which will allow you to activate
emergency mode.
Fault code displayed
8 8
10 Fault code 8 + fault code 2
12 8+4
24 8+16
26 8+2+16
28 8+4+16
138 8+2+128
140 8+4+128
152 8+16+128
154 8+2+16+128
156 8+4+16+128
When the appliance is operating in emergency mode, the fault
code shown is increased by 256.
Notifying a qualified contractor
If you cannot remedy the fault, notify your qualified contractor. To
facilitate and speed up your request, provide the serial number
from the type plate (000000-0000-00000). The type plate can be
found on the left, above the "DHW outlet" connection.
Sample type plate
000000-0000-00000
D0000035352
1
1 Number on the type plate

12 | WWK 220-300 electronic www.stiebel-eltron.com
INSTALLATION
Safety
INSTALLATION
7. Safety
Only a qualified contractor should carry out the installation, com-
missioning, maintenance and repair of the appliance.
7.1 General safety instructions
We guarantee trouble-free function and operational reliability only
if original accessories and spare parts intended for the appliance
are used.
7.2 Instructions, standards and regulations
Note
Observe all applicable national and regional regulations
and instructions.
Take note of the appliance type plate and chapter "Specification".
8. Appliance description
The heat pump drive unit is located in the upper section of the
appliance. The DHW cylinder is located in the lower section of
the appliance.
8.1 Standard delivery
The following are delivered with the appliance:
- Condensate drain bend
- 2 pipe connectors with plastic union nuts and gaskets for the
"cold water inlet" and "DHW outlet" connections.
8.2 Required accessories
Various safety assemblies are available that need to be selected
subject to the respective static pressure. These type-tested safe-
ty assemblies protect the appliance against unacceptable excess
pressure.
8.3 Further accessories
– Condensate pump (if the condensate cannot be drained off with
a naturally occurring fall)
8.4 Incorrect use
The following are not permitted:
- Operating the appliance when the casing is open
- Filling the appliance with a refrigerant other than the one
detailed in chapter "Specification/ Data table"
Observe the list of requirements regarding the installation room
and non-permissible installation sites (see chapter "installation
site").
9. Preparations
9.1 Transport
!
CAUTION Injury
 Take note of the weight of the appliance.
 Use suitable transport aids (e.g. a sack truck) and
enough personnel for transportation.
!
Material losses
The appliance has a high centre of gravity and low over-
turning moment.
 Safeguard the appliance against falling over.
 Only set the appliance down on an even base.
!
Material losses
The appliance casing is not designed to withstand strong
forces. Incorrect handling can lead to material losses of
considerable extent.
 Observe the information on the packaging.
Only remove the packaging shortly before the installation.
Do not unpack the appliance until it has arrived in the installation
room.
Leave the appliance in its packaging and on the pallet. This ena-
bles brief horizontal transport and provides places to hold onto
during transport.
Vehicular transport
!
Material losses
The appliance must generally be stored and transported
vertically.
The appliance may be transported horizontally for brief periods,
over a maximum distance of 100miles and on made-up roads.
Strong shocks are not permissible.
!
Material losses
If transported horizontally, the appliance must always be
laid onto the hatched side of the box.
The appliance must not remain in a horizontal position
for more than 24hours.
If the appliance was transported horizontally, leave it to
rest in a vertical position for at least one hour before
commissioning.
 Observe the information on the packaging.

www.stiebel-eltron.com WWK 220-300 electronic | 13
ENGLISH
INSTALLATION
Preparations
D0000034797
1
1 Recessed grips
Transport from vehicle to installation room
The cardboard box has reinforced recessed grips along the top of
the appliance. You can use these recessed grips, as well as the
pallet at the lower end, to carry the appliance into the installation
room. Take note of the weight of the appliance and ensure a suffi-
cient number of personnel is available for handling the appliance.
9.2 Storage
If it is necessary to store the appliance for a prolonged period
before installation, observe the following information:
- Only store the appliance in a vertical position. Never store
the appliance horizontally.
- Store the appliance in a location that is dry and largely
dust-free.
- Protect the appliance from coming into contact with corrosive
substances.
- Ensure the appliance is not subjected to shocks or vibrations.
9.3 Installation site
The appliance is not approved for outdoor installation.
Further requirements regarding the installation room and appli-
ance positioning, to prevent appliance damage:
- The installation location must be free from flammable, highly
combustible gases and substances, as well as high levels of
dust.
- The installation room must be free from the risk of frost.
- The intake temperature of the appliance must be within the
permissible application limits (see chapter "Specification/
Data table").
- The floor of the installation room must be level and have
sufficient load bearing capacity. Take note of the weight of
the appliance with a full DHW cylinder (see "Specification/
Data table"). A floor with insufficient load bearing capacity is
in danger of collapse. If the appliance is not evenly balanced,
there may be a risk of appliance damage.
- The size of the installation room must correspond to the ap-
plication limits of the appliance (see chapter "Specification /
Data table").
- Observe the safety clearances and protection zones.
- Always leave sufficient space to provide access for instal-
lation, maintenance and cleaning. Observe the required
minimum clearances (see chapter "Preparations/ Siting the
appliance").
- Ensure the operation of other equipment in the installation
room is not impaired.
- To keep the duct lengths as short as possible, we recommend
installing the appliance close to the kitchen or bathroom.
- To prevent adverse effects from operating noise, never install
the appliance close to bedrooms.
The following installation locations are not permissible, due to
risk of appliance damage:
- Locations where the air is contaminated with oil or salt
- Saline environments
- Environments with thermal water
- Areas in proximity to high frequency machines
- Places where the air contains ammonia (e.g.sewage works)
- Places where the air contains chlorine (e.g.swimming pools)
- Generally places where the air is strongly contaminated, e.g.
due to dust, or contains aggressive substances
Note
The performance data indicated for this appliance has
been determined in line with the relevant standard, that
is at an intake temperature of 15°C. Below 15°C the
efficiency of the appliance decreases.
Note
You can improve the efficiency of the appliance by utilis-
ing the waste heat from other appliances to heat the DHW
cylinder, e.g. boilers, tumble dryers or freezers.
Sound emissions
The noise emission is greater on the air intake and air discharge
sides of the appliance than on the closed sides.
 Never direct the air intake or air discharge towards
noise-sensitive rooms of the house, e.g. bedrooms.
Note
For details on noise emission, see chapter "Specification/
Data table".

14 | WWK 220-300 electronic www.stiebel-eltron.com
INSTALLATION
Preparations
9.4 Siting the appliance
 Carefully undo the cardboard packaging at the clips.
D0000034797
1
1 Cardboard packaging clips
The appliance is secured to the pallet with metal brackets and
screws. The metal brackets are hooked on to the feet underneath
the floor plate of the appliance.
1. 2.
D0000034798
1
1 Metal bracket fixing screw
 Remove the fixing screws of the metal brackets from the
pallet.
 Push the metal brackets a little towards the cylinder centre,
to unhook them from the appliance feet.
 Pull the metal brackets out from underneath the appliance.
!
Material losses
Take note of the appliance's weight and centre of gravity.
 Slightly tip the appliance and carefully roll the appliance off
the pallet.
 Position the appliance in its final location.
Minimum clearances
≥100
≥350
≥400
≥400
≥500
D0000020783
 Maintain the minimum clearances.
!
Material losses
The appliance must be positioned vertically to avoid ap-
pliance damage.
The feet under the floor plate of the appliance are
height-adjustable.
 Level the appliance horizontally using the height-ad-
justable feet.
D0000034806

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ENGLISH
INSTALLATION
Installation
10. Installation
!
WARNING Injury
Incorrect installation can lead to serious personal injury
or material losses.
Before any work, ensure sufficient clearances for the
installation.
Handle sharp-edged components carefully.
10.1 Water connection
!
Material losses
Carry out all water connection and installation work in
accordance with regulations.
The following material combinations are approved for metal pipe-
work installations:
Cold water inlet DHW outlet
Copper pipe Copper pipe
Steel pipe Steel pipe or copper pipe
 Thoroughly flush the pipework before connecting the ap-
pliance. Foreign bodies, such as welding pearls, rust, sand
or sealant can impair the operational reliability of the
appliance.
!
Material losses
To protect the connections against corrosion the water
connection must be made with flat gaskets. The use of
hemp on connections is not permissible.
The plastic union nuts included in the standard delivery
serve to prevent and insulate against cathodic scaling due
to highly conductive water.
!
Material losses
Too much torque can destroy the plastic union nuts. This
leads to a risk of appliance damage.
Never exceed a torque of 25Nm when using the gasket
supplied as standard. Keep to the permissible torque.
 Using the gaskets and plastic union nuts provided, connect
the flanged copper pipes included in the standard delivery to
the "cold water inlet" and "DHW outlet" connections.
 Check the gasket and plastic union nut for leaks.
Safety valve
The appliance is a sealed unvented DHW cylinder. Provide the
appliance with a pressure relief valve.
 Install a type-tested safety valve in the cold water supply
line. The response pressure of the safety valve must be below
or equal to the permissible operating pressure of the DHW
cylinder.
The safety valve protects the appliance against unacceptable ex-
cess pressure. The diameter of the cold water supply line must be
no greater than the diameter of the safety valve.
 Ensure that the expansion water escaping from the safety
valve can drip into a drain, e.g. a tank or funnel.
Ensure the drain cannot be shut off.
 Size the drain so that water can drain off unimpeded when
the safety valve is fully opened.
 Ensure that the discharge pipe of the safety valve is open to
atmosphere.
 Fit the discharge pipe of the safety valve with a constant
downward slope and in a room free from the risk of frost.
Pressure reducing valve
The maximum pressure in the cold water supply line must be at
least 20% below the response pressure the safety valve. If the
maximum pressure in the cold water supply line is higher, install
a pressure reducing valve.
Drain valve
 Install a suitable drain valve at the lowest point in the cold
water inlet line.
DHW circulation
The heat losses incurred in the DHW circulation line and the elec-
trical power consumption of the circulation pump reduce the effi-
ciency of the system. The cooled water in the circulation line mixes
with the cylinder content. Where possible, avoid installing a DHW
circulation line. Where that is not possible, the DHW circulation
pump must be controlled thermally or by time switch.
Thermal insulation
 Insulate the DHW line against heat loss in accordance with
locally applicable regulations.
10.2 Connection of an external heat generator (only
WWK300electronicSOL)
!
Material losses
Even if an external heat generator is connected, do not
disconnect the appliance from the power supply as oth-
erwise it is not protected against frost and corrosion. The
power supply must not be interrupted even in winter,
when it is possible that DHW heating is only being pro-
vided via the external heat generator.
!
Material losses
The integration of an external heat generator via the
"Heat source flow" connection must not result in the ap-
plication limits being exceeded (see chapter "Specifica-
tion/ Data table").
The connected external heat generator cannot be con-
trolled by the appliance. The external heat generator
must be controlled externally. The possibility of exceed-
ing the maximum permissible DHW temperature in the
cylinder (as given in chapter "Specification/ Data table")
must be prevented.
!
Material losses
Carry out all installation work in accordance with regula-
tions. In Germany, to comply with heating system regula-
tions, an external heat generator must be connected with
a diaphragm expansion vessel and a safety valve between
the external heat generator and the DHW cylinder.

16 | WWK 220-300 electronic www.stiebel-eltron.com
INSTALLATION
Installation
External heat generators may only be connected with DHW priority
control. As part of this, the cylinder temperature must be captured
with an electronic temperature sensor with safety low voltage.
The DHW cylinder of the appliance allows the temperature sensor
to be positioned at one of two different heights in the cylinder.
Using the sensor well in the upper third of the cylinder enables
later DHW heating through the external heat generator than the
lower sensor position.
10.3 Condensate drain
Install a condensate drain hose in order to remove the condensate
which forms.
 Connect the condensate drain included in the standard deliv-
ery to the "condensate drain" connection.
 Connect a condensate drain hose to the condensate drain
bend.
!
Material losses
Ensure condensate cannot back up.
 Use a condensate drain hose with a diameter great-
er than the diameter of the condensate drain bend.
 Ensure the condensate drain hose is not kinked.
 Route the condensate drain hose with a continuous
fall.
The condensate drain must be open to atmosphere.
 Use a suitable condensate pump if there is insufficient fall.
Observe the building characteristics.
10.4 Power supply
WARNING Electrocution
Carry out all electrical connection and installation work
in accordance with national and regional regulations.
WARNING Electrocution
If the appliance is permanently connected to the power
supply, ensure that the appliance can be separated from
the power supply by an isolator that disconnects omnip-
olar with at least 3mm contact separation. Contactors,
mains isolators or fuses can be used for this.
WARNING Electrocution
 Observe the safety measures to prevent contact
with dangerous 'live' currents.
WARNING Electrocution
Coming into contact with 'live' components presents a
threat to life. Disconnect the appliance from the power
supply before carrying out work on the control panel.
Prevent the power supply from being switched on while
you are working on the system.
WARNING Electrocution
Insufficient earthing can lead to electrocution. Ensure
the appliance is earthed according to locally applicable
requirements.
WARNING Electrocution
The power cable must only be replaced (for example
if damaged) with an original spare part by a qualified
contractor authorised by the manufacturer (connection
typeX).
!
Material losses
The specified voltage must match the mains voltage. Take
note of the type plate.
!
Material losses
Never connect the appliance to the power supply before
the DHW cylinder is filled.
The appliance is delivered with a power cable with mains plug.
Standard connection without external signal transmitter
X0
PE
PE
N
N
L1
L1
LF
FB
D0000034487
10.4.1 Connection with external signal transmitter
An external signal transmitter for switching a separate set DHW
temperature (set temperature2) can be connected to terminal
X0/LF.
In the delivered condition, terminal X0/LF is not assigned. If this
terminal is connected to 230V, the appliance activates set tem-
perature2.
Following a one-off activation (signal is present for at least one
minute), set temperature2 applies for at least 20minutes and is
ranked higher than set temperature1.
WARNING Electrocution
If the 230V signal of an external signal transmitter is
to be connected to terminal X0/LF, do not connect the
appliance to the power supply with the factory fitted
power cable and standard plug.
Instead connect the appliance to the power supply per-
manently. Never interchange L1 and N.
Note
 Never wire up terminal X0/FB.

www.stiebel-eltron.com WWK 220-300 electronic | 17
ENGLISH
INSTALLATION
Commissioning
Example 1: Power-OFF signal with own 230V phase
X0
FB
LF
L1
L1
N
N
PE
PE
L1
L1, L2 oder L3
N
PE
EVU:
D0000034589
Example 2: Photovoltaic signal via on-site relay and phase
routed outside the appliance
Note
The relay in the inverter must meet the following re-
quirements:
- Potential-free relay (240VAC / 24VDC, 1A) with
N/O contact
- Adherence to safety regulations and standards for
safety extra low voltage
- The switching output must be programmed so that
the relay closes or opens if certain limits are exceed-
ed or undershot (inverter output level).
If necessary, check with the inverter manufacturer wheth-
er the product meets the stated criteria.
X0
FB
LF
L1
L1
N
N
PE
PE
L1
N
PE
1
D0000034590
1 Inverter (floating contact)
The inverter power feed is located at a central distribution point
(e.g. in the main fuse box).
Connection to terminal block X0
 Remove the appliance cover (see chapter "Cleaning and
maintenance/ Removing the appliance cover").
D0000034803
1
1 Terminal X0
 Prepare the leads for connection to X0 in such a manner, that
each lead terminating at X0 has a wire ferrule.
 Route leads through the strain relief.
 Connect the leads to X0 (see chapter "Connection with exter-
nal signal transmitter").
10.5 Assembling the appliance
Note
Refit the appliance cover after completing your work. See
chapter "Maintenance and cleaning/ Fitting the appliance
cover").
11. Commissioning
11.1 Commissioning
!
Material losses
Never connect the appliance to the power supply before
the DHW cylinder is filled.
Note
At temperatures below –15°C the high limit safety cut-out
may respond. The appliance may be subjected to these
temperatures during storage or transport.
 If required, press the high limit safety cut-out reset
button.
Note
Following an interruption of the power supply, the
compressor operation remains blocked for at least one
minute. The PCB delays electronic starting by a minute,
during which the appliance goes through its initialising
process.
If the compressor subsequently fails to start, it may be
blocked by additional safety devices (Klixon and high
pressure switch). This block should lift after 1 to 10min-
utes.

18 | WWK 220-300 electronic www.stiebel-eltron.com
INSTALLATION
Shutting down
11.1.1 Filling the DHW cylinder
Fill the DHW cylinder and vent the pipework by following the
procedure below:
 Close the drain valve.
 Open all DHW draw-off points and the shut-off valve in the
cold water supply.
 Close the DHW draw-off points as soon as water starts to
emerge from them.
 Check the safety valve by leaving it open until water runs out.
11.1.2 Settings / function check
 To check the function, select the maximum set temperature.
Note
Following an interruption of the power supply, the
compressor operation remains blocked for at least one
minute. The PCB delays electronic starting by a minute,
during which the appliance goes through its initialising
process.
If the compressor subsequently fails to start, it may be
blocked by additional safety devices (Klixon and high
pressure switch). This block should lift after 1 to 10min-
utes.
Establish the customer's comfort requirements and select the ap-
propriate set DHW temperature. For information regarding DHW
demand, consult VDI guideline2067.
Following completion of the function check, reduce the set DHW
temperature for a more energy-concious appliance operation.
11.1.3 Appliance handover
 Explain the appliance function to users and familiarise them
with its operation.
 Make users aware of potential dangers, especially the risk of
scalding.
 Make users aware of critical environmental factors and re-
quirements concerning the installation location.
 Inform users that water may drip from the safety valve dur-
ing the heating operation.
 Hand over these operating and installation instructions to
users for safe-keeping.
11.2 Recommissioning
If the appliance is switched off due to an interruption to the power
supply, no specific measures for restarting are required once the
power supply has been restored. The appliance has saved the
parameters most recently set and continues operating with these.
If the rapid/comfort heating function was active before interrup-
tion of the power supply, this is reactivated with a set temperature
of 65°C once the power supply has been restored.
Emergency mode is not reactivated after an interruption of the
power supply.
Note
Following an interruption of the power supply, the
compressor operation remains blocked for at least one
minute. The PCB delays electronic starting by a minute,
during which the appliance goes through its initialising
process.
If the compressor subsequently fails to start, it may be
blocked by additional safety devices (Klixon and high
pressure switch). This block should lift after 1 to 10min-
utes.
12. Shutting down
!
Material losses
If you disconnect the appliance from the power supply, it
is no longer protected against frost.
 Only disconnect the appliance from the power sup-
ply for longer periods if you are also draining the
DHW cylinder.
If you want to switch the appliance off for a longer period, always
drain the DHW cylinder. See chapter "Maintenance / Draining the
appliance".
The appliance can only be switched off by interrupting the power
supply.
 Pull the mains plug from the socket or disconnect the appli-
ance from the mains at the MCB/fuse in the fuse box.
13. Troubleshooting
WARNING Electrocution
Prior to all work on the appliance, isolate it from the
power supply.
!
Material losses
If you disconnect the appliance from the power supply, it
is no longer protected against frost.
 Only disconnect the appliance from the power sup-
ply for longer periods if you are also draining the
DHW cylinder.
 For work inside the appliance, remove the appliance cover
(see chapter "Cleaning and maintenance/ Removing the ap-
pliance cover").
 If necessary, remove the upper section of the casing jacket
(see chapter "Maintenance and cleaning/ Removing the cas-
ing ring").
Note
Refit the casing ring after completing the work. See chap-
ter "Maintenance and cleaning/ Fitting the casing ring".
Note
Refit the appliance cover after completing your work. See
chapter "Maintenance and cleaning/ Fitting the appliance
cover").

www.stiebel-eltron.com WWK 220-300 electronic | 19
ENGLISH
INSTALLATION
Maintenance and cleaning
13.1 Fault table
Fault Cause Remedy
The appliance
switches off
unexpectedly
and does not
switch on
again.
Excessive pressure in
the refrigerant circuit.
The safety pressure lim-
iter has responded. The
compressor has been
switched off.
Eliminate the cause of the in-
crease in pressure in the refriger-
ant circuit.
Wait approx.5 to 15minutes for
the appliance to equalise the
pressure. Reset the safety pres-
sure limiter (see chapter "Trou-
bleshooting / Resetting the safety
pressure limiter").
The appliance is operated
outside the application
limits. The ambient tem-
perature is higher than
the permissible value.
The safety pressure limit-
er has responded.
Ensure that the application limits
are observed.
Wait approx.5 to 15minutes for
the appliance to equalise the
pressure. Reset the safety pres-
sure limiter (see chapter "Trou-
bleshooting / Resetting the safety
pressure limiter").
The compres-
sor switches off
unexpectedly.
The thermal load of the
compressor has been ex-
ceeded. The motor over-
load relay has responded.
Remedy the cause of the high
thermal load. Wait until the appli-
ance restarts.
The appliance
generates less
heat.
An inadequate air flow
across the evaporator
may be a possible cause.
Check whether the fan is contam-
inated. Check whether the evapo-
rator is contaminated. Ensure that
supply and extract air flow are
unimpeded.
For explanations of the fault codes, see chapter "Troubleshooting".
13.2 Resetting the safety pressure limiter
The safety pressure limiter shuts down the compressor if the
pressure inside the refrigerant circuit exceeds the permissible
maximum value. The safety pressure limiter may also respond if
the appliance is operated above its permissible application limit
or the temperature controller of the heat pump fails to respond.
D0000034801
12
1 Reset button for safety pressure limiter
2 Reset button for high limit safety cut-out
 After removing the cause of the fault, reset the safety pres-
sure limiter by pressing the reset button.
13.3 Resetting the high limit safety cut-out
The high limit safety cut-out protects the appliance from overheat-
ing. The electric emergency/booster heater is switched off when
the cylinder water temperature exceeds 87±5°C.
Once the cause of the fault has been removed, press the reset
button of the high limit safety cut-out on the rod thermostat. To
do so, remove the appliance cover.
13.4 Motor overload relay
In the event of excessive thermal load on the compressor, the
motor overload relay switches the compressor off.
 Remove the cause.
After a short cooling period, the motor overload relay will restart
the compressor automatically.
14. Maintenance and cleaning
WARNING Electrocution
Prior to all work on the appliance, isolate it from the
power supply.
14.1 Removing the appliance cover
D0000035322
 Undo the screw (Torx) that fastens the control fascia and the
appliance cover to the appliance.
 Push the control fascia upwards.
D0000034802
 Remove the control fascia.
 A lead connects the operating controls to the appliance PCB.
If necessary, pull the plug from the back of the control fascia
to fully remove the control fascia.
 Carefully lift away the appliance cover and undo the earth
cable that runs from the appliance control panel to the cover.
Note
Refit the appliance cover after completing your work. See
chapter "Maintenance and cleaning/ Fitting the appliance
cover").

20 | WWK 220-300 electronic www.stiebel-eltron.com
INSTALLATION
Maintenance and cleaning
14.2 Removing the casing ring
Note
If you require more space to work inside the appliance,
you can remove the casing on the upper section of the
appliance.
D0000034803
1
1 Fixing screws on casing ring
The casing ring is fastened with screws.
 Undo the fixing screws on the casing.
 Remove the condensate drain bend and pipe collar of the
drain. Turn anti-clockwise to undo.
!
Material losses
An earth cable is connected to the inside of the casing
ring. The casing can only be removed after the earth
cable has been detached.
D0000034814
The casing ring overlaps along the joint. A tab on one end clips
into the recess on the other end of the casing ring.
 Ease the casing ring apart, until it can be removed or slid
downwards.
Note
Refit the casing ring after completing the work. See chap-
ter "Maintenance and cleaning/ Fitting the casing ring".
14.3 Cleaning the evaporator
!
WARNING Injury
The evaporator consists of numerous sharp-edged fins.
Be careful when cleaning the evaporator and wear pro-
tective clothing, especially safety gloves.
To maintain a consistently high appliance output, check the evap-
orator of the appliance regularly for contamination and clean as
necessary.
 Undo the screw that secures the appliance cover at the upper
side of the control fascia.
 Remove the control fascia and the appliance cover.
 Carefully clean the evaporator fins. Only use water and a soft
brush for this. Never use acidic or alkaline cleaning agents.
14.4 Draining the cylinder
WARNING Burns
Hot water may escape when draining the DHW cylinder.
To drain the DHW cylinder, e.g. when shutting the appliance down,
proceed as follows:
 Isolate the appliance from the power supply.
 Close the shut-off valve in the cold water supply line.
The DHW cylinder is drained via the cold water supply line.
 Open the drain valve installed in the cold water supply line
(see chapter "Water connection"). If no drain valve has been
installed, undo the cold water supply line at the "cold water
inlet" connection.
 To vent the system, undo the DHW line connected to the
"DHW outlet" connection.
Some residual water will remain in the lower section of the DHW
cylinder.