STIEBEL ELTRON WWK 222 Specification sheet

OPERATION AND INSTALLATION
DHW heat pump
» WWK222
» WWK222H
» WWK302
» WWK302H

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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
2. Safety����������������������������������������������������������4
2.1 Intended use������������������������������������������������������ 4
2.2 General safety instructions ������������������������������������ 4
2.3 Test symbols ������������������������������������������������������ 5
3. Appliance description ���������������������������������������5
3.1 Heat pump operating principle ������������������������������� 6
3.2 DHW heating������������������������������������������������������ 6
3.3 Appliance operation outside the application limits������� 6
3.4 Frost protection �������������������������������������������������� 6
3.5 Minimum runtime and minimum pause time�������������� 7
3.6 Connection of an external signal transmitter �������������� 7
4. Settings �������������������������������������������������������7
5. Cleaning, care and maintenance ���������������������������7
6. Troubleshooting ����������������������������������������������9
INSTALLATION
7. Safety�������������������������������������������������������� 10
7.1 General safety instructions ����������������������������������� 10
7.2 Instructions, standards and regulations ������������������� 10
8. Appliance description ������������������������������������� 10
8.1 Standard delivery����������������������������������������������� 10
8.2 Required accessories ������������������������������������������ 10
8.3 Further accessories��������������������������������������������� 10
8.4 Incorrect use����������������������������������������������������� 10
9. Preparations ������������������������������������������������ 10
9.1 Transport ��������������������������������������������������������� 10
9.2 Storage������������������������������������������������������������ 11
9.3 Installation site�������������������������������������������������� 11
9.4 Siting the appliance �������������������������������������������� 12
10. Installation�������������������������������������������������� 13
10.1 Water connection ����������������������������������������������� 13
10.2 Condensate drain ����������������������������������������������� 14
10.3 Power supply ���������������������������������������������������� 14
10.4 Assembling the appliance ������������������������������������ 17
11. Commissioning ��������������������������������������������� 18
11.1 Initial start-up��������������������������������������������������� 18
11.2 Recommissioning����������������������������������������������� 18
12. Shutdown ��������������������������������������������������� 18
13. Troubleshooting �������������������������������������������� 19
13.1 Resetting the safety pressure limiter ����������������������� 19
13.2 Resetting the high limit safety cut-out (only WWKH)��� 19
13.3 Motor overload relay������������������������������������������� 19
14. Maintenance ������������������������������������������������ 20
14.1 Removing the appliance cover ������������������������������� 20
14.2 Removing the casing ring������������������������������������� 20
14.3 Cleaning the evaporator��������������������������������������� 20
14.4 Draining the cylinder ������������������������������������������ 21
14.5 Descaling the electric emergency/booster heater ������� 21
14.6 Valves ������������������������������������������������������������� 21
14.7 Condensate drain ����������������������������������������������� 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 ������������������������������������������������� 24
15.3 Data table �������������������������������������������������������� 26
WARRANTY
ENVIRONMENT AND RECYCLING

ENGLISH
www.stiebel-eltron.com WWK222-302 H | 3
SPECIAL INFORMATION
SPECIAL INFORMATION
- 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 resulting risks. Children must never play with
the appliance. Children must never clean the ap-
pliance or perform user maintenance unless they
are supervised.
- Observe all applicable national and regional reg-
ulations and instructions.
- Observe the minimum clearances (see chap-
ter "Installation/ Preparations/ Siting the
appliance").
- Observe the requirements concerning the instal-
lation room (see "Specification/ Data table").
- The connection to the power supply must be
in the form of a permanent connection. Ensure
the appliance can be separated from the power
supply by an isolator that disconnects all poles
with at least 3mm contact separation. Contac-
tors, circuit breakers or fuses can be used for
this. This type of isolator must be installed in the
fixed electrical installation according to the wiring
rules. For Australia: Ensure that the appliance can
be separated from the power supply by a suitable
isolator. Contactors, circuit breakers or fuses can
be used for this. This type of isolator must be in-
stalled in accordance with the wiring rules.
- 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").
- If the power cable is faulty, replace it with a new
one. The power cable must only be replaced (for
example if damaged) by a qualified contractor.
- The appliance is pressurised. During the heat-up
process, expansion water will drip from the safety
valve.
- Activate any valves at least once every 6months
to prevent blockages, e.g. by limescale deposits.
- Drain the appliance as described in "Installa-
tion/ Maintenance and cleaning/ Draining the
cylinder".
- A T&P valve or a safety valve (cold water expan-
sion control valve) must be installed. Observe all
applicable national and regional regulations and
instructions.
- The maximum pressure in the cold water supply
line must be at least 20% below the response
pressure of the lowest pressure rated valve in-
stalled, otherwise a pressure reduction valve will
be required. If this is the case, install a pressure
reduction valve in the cold water feed. The pres-
sure reducing valve must be set to 440kPa if a
safety valve is installed; otherwise to 550kPa.
- Fit the discharge pipe of the safety valve with
a constant downward slope and in a room free
from the risk of frost.
- Size the drain so that water can drain off unim-
peded when the safety valve is fully opened.
- 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 both the user 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 any new user where appro-
priate.
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 adjacent symbol.
 Read these texts carefully.
Symbol Meaning
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.
1.3 Units of measurement
Note
All measurements are given in mm unless stated oth-
erwise.
2. Safety
2.1 Intended use
The purpose of this appliance is to heat domestic hot water within
the application limits stated in the chapter "Specification / data
table".
This appliance is intended for domestic use. It can be used safely
by untrained persons. The appliance can also be used in a non-do-
mestic 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.
2.2 General safety instructions
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 older
and persons with reduced physical, sensory or mental
capabilities or a lack of experience and know-how, pro-
vided that they are supervised or they have been in-
structed 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 ap-
pliance or perform user maintenance unless they are
supervised.
WARNING Electrocution
Contact with live components presents a threat to life.
Damage to the cable insulation or to individual compo-
nents may result in a risk to life.
 If there is damage to the insulation, switch off the
power supply and arrange a repair.
All work on the electrical installation must be carried
out by a qualified contractor.
!
!

OPERATION
Appliance description
ENGLISH
www.stiebel-eltron.com WWK222-302 H | 5
WARNING Burns
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
protective 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 Burns
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.
WARNING Electrocution
Never operate the appliance when the casing is open or
without a cover.
!
CAUTION Injury
If objects are left on the appliance, noise emissions may
increase due to resulting vibrations, and the objects
could fall and cause injury.
 Never place any objects on top of the appliance.
!
Material losses
At the factory, the appliance is fitted with rechargeable
batteries that ensure the power supply to the impressed
current anode in the case of a power failure.
To enable the impressed current anode to provide pro-
tection against corrosion, the power supply to the appli-
ance must not be interrupted for more than 16 hours if
the DHW cylinder is filled with water and the anode is
not connected separately to a continuous power supply
source.
If regular interruptions to the power supply are not antic-
ipated, the batteries will require no maintenance.
Every three years, you must replace the batteries for the
impressed current anode in the following cases:
- The impressed current anode is not connected sep-
arately to a continuous power supply source and
a switching contact regularly interrupts the power
supply to the appliance.
- The security of supply is inadequate.
Neglecting to do this puts the appliance at risk of damage.
Never use batteries that cannot be charged. Only nick-
el-metal hydride (Ni-MH) rechargeable batteries are
permissible.
Batteries may be damaged in the appliance. Without a
power supply, the impressed current anode and the cyl-
inder would not be protected against corrosion.
!
Material losses
Ensure that the appliance, the water pipes and safety
valves are free from any risk of frost. If you disconnect the
appliance from the power supply, it is no longer protected
against frost.
!
Material losses
Never cover the 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. If the DHW cylinder is empty, safety equip-
ment switches off the appliance.
!
Material losses
Heating liquids other than potable water is not permitted.
!
Material losses
Keep the appliance installation site free from air contam-
inated with oil or salt (chloride) and corrosive or explo-
sive substances. Avoid contaminating the installation site
with dust, hairspray or substances containing chlorine
or ammonia.
!
Material losses
Operating the appliance outside the application limits
(see "Specification/ Data table") is not permitted. The
appliance may be damaged if operated continuously out-
side the application limits.
Note
The appliance is pressurised. During the heat-up process,
expansion water will drip from the safety valve.
 If water continues to drip when heating is complet-
ed, inform your qualified contractor.
2.3 Test symbols
See type plate on the appliance.
3. Appliance description
This appliance enables DHW to be supplied efficiently to several
draw-off points using renewable energy. 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
electrical energy and time required to heat up the DHW depend
on the temperature of the air drawn in. When the air inlet tem-
perature drops, the appliance output is reduced and the heat-up
time is extended.
Subject to the power supply and user draw-off behaviour, the
water is heated automatically to the selected set temperature. The
appliance heats up the water to a temperature which is selected
at the factory.

OPERATION
Appliance description
6| WWK222-302 H www.stiebel-eltron.com
In the case of indoor installation, the air inside the installation
room can be cooled by 1°C to 3°C through heat extraction. 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 inflow of cold water.
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. To protect against corrosion, the DHW cylinder is coated
internally with special enamel and is additionally equipped with
an impressed current anode.
3.1 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 drawn in, the refrigerant changes from a liquid into a gas-
eous 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 transfers heat to the DHW cylinder. An expansion valve
then reduces the still prevalent pressure and the cyclical process
starts again.
3.2 DHW heating
2
1
D0000050335
1 Cylinder top sensor
2 Integral sensor
The appliance is equipped with two temperature sensors.
- The cylinder top sensor captures the water temperature in
the upper section of the cylinder.
- The integral sensor is a temperature sensor affixed over the
entire cylinder height. The integral sensor determines the
average cylinder temperature.
The appliance control unit uses the average cylinder temperature
captured by the integral sensor. DHW heating is started when
the average cylinder temperature has fallen below the set tem-
perature.
DHW is normally heated by the heat pump of the appliance (see
chapter "Specification/ Data table").
Note
If the appliance has been isolated from the power supply
during operation, the compressor will only restart after
the pressure inside the refrigerant circuit has been equal-
ised. Pressure compensation can take several minutes.
WWK222H|WWK302H: Electric emergency/booster heater
When the temperature in the upper section of the DHW cylinder
drops 10K below the selected set temperature, the appliance
automatically switches on the electric emergency/booster heater.
When the temperature in the upper section of the DHW cylinder
rises 2K above the selected set temperature, the appliance switch-
es off the electric emergency/booster heater.
3.3 Appliance operation outside the application
limits
3.3.1 Ambient temperatures below the application limit
Outside the application limits, the appliance disables the com-
pressor operation. This could lead to reduced DHW convenience.
If the appliance has an electric emergency/booster heater, this
will be enabled if a demand for heating up the water exists and
the lower application limit is underrun.
Low ambient temperatures may result in the formation of hoar
frost on the evaporator depending on the air humidity and water
temperature.
Active defrost feature
The appliance is equipped with active hot gas defrosting, which
allows quick defrosting of the evaporator when needed. During
defrosting, the appliance fan is disabled and the compressor con-
tinues to run. A solenoid valve routes the hot gas directly to the
evaporator. While this is happening, the condenser is disabled by
another solenoid valve.
In contrast to conventional defrosting methods, the appliance
guarantees that defrosting takes place only when needed.
Note
Heat-up times are longer while the evaporator is defrost-
ing.
3.3.2 Ambient temperatures above the application limit
Outside the application limits, the appliance disables the com-
pressor operation. This could lead to reduced DHW convenience.
If the appliance has an electric emergency/booster heater, this
will be enabled if a demand for heating up the water exists and
the lower application limit is underrun.
3.4 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
ENGLISH
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3.5 Minimum runtime and minimum pause time
!
Material losses
When operating with external switching devices that can
interrupt the power supply to the appliance, such as time
switches, energy management systems or home automa-
tion systems, observe the following conditions:
- The minimum ON time is 60 minutes.
- The minimum pause time following a shutdown is
20 minutes.
- The appliance should not be switched on/off more
than 10 times per day.
- The breaking capacity of the switching element must
meet the fuse rating requirements (see chapter
“Specification/ Data table”).
!
Material losses
If you disconnect the appliance from the power supply, it
is no longer protected against frost.
!
Material losses
At the factory, the appliance is fitted with rechargeable
batteries that ensure power supply to the impressed cur-
rent anode in the case of a power failure.
To enable the impressed current anode to provide pro-
tection against corrosion, the power supply to the appli-
ance must not be interrupted for more than 16 hours if
the DHW cylinder is filled with water and the annode is
not connected separately to a continuous power supply
source.
If regular interruptions to the power supply are not antic-
ipated, the batteries will require no maintenance.
Every three years, you must replace the batteries for the
impressed current anode in the following cases:
- The impressed current anode is not connected sep-
arately to a continuous power supply source and
a switching contact regularly interrupts the power
supply to the appliance.
- The security of supply is inadequate.
Neglecting to do this puts the appliance at risk of damage.
Never use batteries that cannot be charged. Only nick-
el-metal hydride (Ni-MH) rechargeable batteries are
permissible.
Batteries may be damaged in the appliance. Without a
power supply, the impressed current anode and the cyl-
inder would not be protected against corrosion.
3.6 Connection of an external signal transmitter
Note
This type of connection must only be carried out by a
qualified electrician.
External signal transmitters can be integrated via the built-in con-
tact input, e.g. a PV system to make use of solar power generated
on site.
The appliance has a second set temperature preselected at the fac-
tory. This is activated in the event of an external switching signal.
Set temperature2 takes priority over the standard set temperature
while there is an external switching signal.
Following a one-off activation (signal is present for at least 1min-
ute), set temperature2 applies for at least 20minutes and is ranked
higher than set temperature1.
The qualified contractor can use software to change set temper-
ature2 with an accessory available from us.
4. Settings
Adjustments are not necessary. The DHW temperature has been
set at the factory.
Emergency shutdown
In the event of an emergency, carry out the following steps:
 Disconnect the appliance from the mains at the MCB/fuse in
the fuse box.
 Shut off the cold water supply.
5. Cleaning, care and maintenance
WARNING Electrocution
-Only clean the exterior of the appliance.
-Never open the appliance.
-Do not insert objects through the grills into the inte-
rior of the appliance.
-Never spray the appliance with water.
-Never spray water into the appliance.
!
WARNING Injury
Maintenance work, such as checking electrical safety,
must only be carried out by a qualified contractor.
Appliance
components
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 dis-
charge grille
Clean the air intake grille and air discharge grille every six
months. Cobwebs or other kinds of contamination could ob-
struct the air supply to the appliance.
DHW cylinder The DHW cylinder is equipped with a maintenance-free
impressed current anode to safeguard it against corrosion.
The power supply must not be interrupted for more than 16
hours while the DHW cylinder is filled with water to enable
the impressed current anode to provide protection against
corrosion.
Electric emer-
gency/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.
Safety equip-
ment
Activate any valves at least once every 6months to prevent
blockages, e.g. by limescale deposits.
Evaporator Have the evaporator checked regularly by a qualified contrac-
tor.
Condensate
drain
Undo the condensate drain. Check that the condensate drain
is clear and remove any dirt from the condensate drain con-
nection.

OPERATION
Cleaning, care and maintenance
8| WWK222-302 H www.stiebel-eltron.com
Protective anode and battery replacement
The appliance is equipped with a maintenance-free, impressed
current anode that protects the tank from corrosion while it is
supplied with power. At the factory, the appliance is fitted with
rechargeable batteries that ensure the power supply to the im-
pressed current anode in the case of a power failure. The power
supply may be interrupted for up to 16 hours.
If the power supply is regularly interrupted by a switching con-
tact or the security of supply is inadequate, the batteries of the
impressed current anode must be replaced every three years. Ne-
glecting to do this puts the appliance at risk of damage. If regular
interruptions in the power supply are not anticipated and there
is security of supply, no maintenance of the batteries is required
and the appliance is maintenance-free in this regard.
!
Material losses
Never use batteries that cannot be charged. Only re-
chargeable batteries are permissible.
Batteries may be damaged in the appliance. Without a
power supply, the impressed current anode and the cyl-
inder would not be protected against corrosion.
The rechargeable batteries are secured at the back of the fascia.
D0000040621
 Undo the screw securing the fascia.
 Carefully remove the fascia so that the cables running from
the batteries to the impressed current anode in the appliance
are not pulled out.
D0000051618
1
1 Plug-in connection
 Undo the plug-in connection by pressing the connection lock
on both sides.
D0000051617
1
1 Battery compartment
 Pull the battery compartment down to remove it from the
retainer.
 Open the battery compartment using a screwdriver.
 Replace the batteries (NiMH, type AAA, ≥800mAh).
!
Material losses
Make sure that the batteries are properly inserted the
right way round, because otherwise there will be no
corrosion protection in the event of interruptions in the
power supply.
 Close the battery compartment using a screwdriver.
 Push the battery compartment into the retainer.
 Reconnect it to the appliance with the plug-in connection.

OPERATION
Troubleshooting
ENGLISH
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6. Troubleshooting
Problem Cause  Remedy
No hot water
is available.
No power at the appliance. Check that the appliance is con-
nected to the power supply.
A fuse/MCB in the fuse box
has blown/responded.
Check whether the fuses/MCBs
in your fuse box have blown/
responded. Contact a qualified
contractor if the fuse blows or
the MCB responds again after
the appliance is connected to the
power supply.
The air intake or air discharge
of the appliance is blocked.
Check the air intake grille and
air discharge grille for contami-
nation. Remove any contamina-
tion (see chapter "Maintenance
and care").
Outside the application lim-
its, the appliance blocks the
compressor. This could lead to
reduced DHW convenience.
No action required. The appli-
ance will then restart the com-
pressor automatically.
The DHW cylinder is not com-
pletely full.
The appliance restarts automati-
cally when the DHW cylinder has
been filled.
Due to a previous high de-
mand for hot water, the unit
has not had the chance to
fully recover.
No action required. Allow the
unit to continue operating nor-
mally until the heating cycle is
completed.
The safety pressure limiter
has responded 5 times in
5hours.
Notify a qualified contractor who
will reset the safety pressure
limiter.
A safety valve
is dripping.
These units are under water
mains pressure. During the
heat-up process, expansion
water will drip from a safety
valve.
If water continues to drip when
heating is completed, please in-
form your qualified contractor.
The conden-
sate drain
drips.
The surface temperature of
the evaporator is lower than
the dew point temperature of
the ambient air. Condensate
forms.
This is expected and no action
is required. The amount of
condensate depends on the air
humidity level.
For indoor in-
stallations 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 tem-
perature 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.
Notifying a qualified contractor
If you cannot remedy the fault, notify your qualified contractor. In
Australia direct notify us (1800153351). To facilitate and speed up
your request, provide the number from the type plate (000000-
0000-000000). The type plate can be found on the left, above the
DHW outlet connection.
Sample type plate
000000-0000-000000
D0000035352
1
1 Number on the type plate

10 | WWK222-302 H www.stiebel-eltron.com
INSTALLATION
Safety
INSTALLATION
7. Safety
Only a qualified contractor should carry out installation, commis-
sioning, 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 straight pipe adapters G1 to G3/4 (use subject to type of
installation, see chapter "Preparations/ Siting the appliance/
Minimum clearances") comprising a flanged pipe, a gasket
and a union nut
- 2 135° pipe adapters G1 to G3/4 union nut (use subject to
type of installation, see chapter "Preparations/ Siting the ap-
pliance/ Minimum clearances")
8.2 Required accessories
Various safety assemblies are available that need to be selected
subject to the static pressure. These type-tested safety 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"
- Heating liquids other than potable water
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
 Observe the weight of the appliance.
 Use suitable transport aids (e.g. a pallet trolley) 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.
Where possible, do not unpack the appliance until it has arrived
in the installation room.
For transport and handling leave the appliance in its packaging
and on the pallet. This enables brief horizontal transport and pro-
vides places to hold on to during transport.
If the appliance has to be unpacked before transportation, we
recommend using a pallet trolley. Pad the contact surfaces to avoid
damaging the appliance. Secure the appliance to the pallet trolley
using a strap. Pad between the strap and the appliance and avoid
overtightening the strap. Where stair wells are narrow, you can
carry the appliance by the handles on the pallet trolley and the
foot of the appliance.
Vehicular transport
!
Material losses
The appliance must generally be stored and transported
vertically.
A transport lock fitted at the factory to the refrigerant circuit
area inside the appliance enables relatively short transportation
horizontally over a maximum distance of 160km of paved roads.
Strong shocks are not permissible.
!
Material losses
If transported horizontally, the appliance must always be
laid on the shaded 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.

ENGLISH
www.stiebel-eltron.com WWK222-302 H | 11
INSTALLATION
Preparations
D0000034797
1
1
1 Recessed grips
Transport from vehicle to installation room
The cardboard box has reinforced handholds (recessed grips). 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 sufficient 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
!
Material losses
Observe the following list of requirements regarding the
installation site.
- Install the appliance where it will be as little exposed to
strong direct wind, extrem rain, sun or snow as possible, but
will still be well ventilated. Unhindered air intake and air dis-
charge should be possible. If necessary, protect the appliance
against the elements with a canopy, base and deflectors.
- The installation site must be free from flammable, highly
combustible gases and substances, as well as high levels of
dust.
- The application limits for the heat pump and DHW cylinder
must be maintained (see chapter "Specification/ Data table").
- The substrate of the installation site must be level and have
sufficient load bearing capacity. Take note of the weight of
the appliance with a full DHW cylinder (see chapter "Speci-
fication/ Data table"). A floor with insufficient load bearing
capacity is in danger of collapse. If the appliance is not level,
there may be a risk of appliance damage.
- In the case of indoor installation, the size of the installation
room must correspond to the application limits of the appli-
ance (see chapter "Specification/ Data table").
- Observe the safety clearances and protection zones.
- Always leave sufficient space to provide access for installa-
tion, maintenance and cleaning. Observe the minimum clear-
ances (see "Preparations/ Siting the appliance").
- Ensure the operation of other equipment in the installation
room is not impaired.
- To keep the length of the water pipes as short as possible,
we recommend installing the appliance close to the kitchen
or bathrooms.
- To prevent adverse effects from operating noise, never install
the appliance close to bedrooms.
!
Material losses
Never install or draw off supply air from locations with
aggressive atmospheres. This may damage the appliance.
 Check the wider environment around the planned
installation site. Check for anything which may have
adverse effects on the installation site or the air
supply.
Examples of unacceptable in-
stallations
Atmospheres containing ammonia sewage works, pigsties
Substances which block the evap-
orator
Air containing oil or fat, dust (cement,
flour, etc.). Note: If the air contains hair-
spray (e.g. in hairdressing salons) the
appliance should only be operated with
reduced maintenance intervals.
Saline atmospheres Coastal installations (< 200m from coast
line) may reduce the life of components.
atmospheres containing chlorine or
chloride
swimming pools, salt works
atmospheres containing thermal
water
Areas in proximity to high frequency
machines
inverters for large motors, radar, etc.
If the air contains hairspray (e.g. in hairdressing salons), the appli-
ance should only be operated with reduced maintenance intervals.
Note
The output data given for this appliance has been de-
termined in accordance with the relevant standard 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 sound emissions are louder 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.

12 | WWK222-302 H www.stiebel-eltron.com
INSTALLATION
Preparations
Note
For details on sounds emissions, see chapter "Specifica-
tion/ Data table".
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 the final installation site.
!
Material losses
The appliance must be positioned vertically to avoid
damage.
The feet under the floor plate of the appliance are
height-adjustable.
 Level the appliance horizontally using the height-ad-
justable feet.
D0000039043
9.4.1 Minimum clearances
 Maintain the minimum clearances.
Connecting with straight pipe adapters
≥150
≥350
≥400
≥400
≥500
D0000029620
Note
If you install the supplied bracket pipe adapters on the
"Cold waterinlet" and "DHW outlet" connections, you can
reduce the minimum clearance at the back of the appli-
ance described in the following installation.

ENGLISH
www.stiebel-eltron.com WWK222-302 H | 13
INSTALLATION
Installation
Connecting with bracket pipe adapters (mainly in Australia)
With these options, the "Cold waterinlet" and "DHW outlet" con-
nections are located on the right hand side or on the left behind
the appliance.
≥400≥400
≥500 ≥100
≥400≥400
≥500 ≥100
D0000055463
10. Installation
!
WARNING Injury
Incorrect installation can lead to serious injury or ma-
terial 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.
!
Material losses
The cathodic corrosion protection can only be guaranteed
when the electrical conductivity of the domestic hot water
is within the limits stated in the chapter "Specification/
Data table".
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 appli-
ance. Foreign bodies, such as plastic and metal shavings,
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.
 Install the DHW outlet line and the cold water inlet line (see
chapter “Specification / Dimensions and connections”).
10.1.1 Safety equipment
A T&P valve or a safety valve (cold water expansion control valve)
has to be installed. Observe all applicable national and regional
regulations and instructions.
T&P valve (700 kPa)
 If specified, install a type-tested T&P valve using the corre-
sponding connection on the appliance.
The response pressure of the valve must be below or equal to the
permissible operating pressure of the DHW cylinder. The valve
protects the appliance against unacceptable pressure or temper-
ature rises. The diameter of the cold water supply line must be no
greater than the diameter of the valve.
 Ensure that the expansion water escaping from the valve can
drip into a drain, e.g. a tundish.
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 location free from the risk of frost.

14 | WWK222-302 H www.stiebel-eltron.com
INSTALLATION
Installation
Safety valve (cold water expansion control valve, 550 kPa)
 If specified, install a type-tested 550 kPa safety valve (expan-
sion control valve) in the cold water supply line.
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.
10.1.2 Pressure reducing valve
The maximum pressure in the cold water supply line must be at
least 20% below the response pressure of the lowest pressure
rated valve installed, otherwise a pressure reduction valve will be
required. If this is the case, install a pressure reduction valve in
the cold water feed. The pressure reducing valve must be set to
440 kPa if a safety valve is installed; otherwise to 550 kPa.
10.1.3 Drain valve
 Install a suitable drain valve at the lowest point in the cold
water inlet line.
10.1.4 Thermal insulation
 Insulate the DHW line and valves against heat loss and to im-
prove energy efficiency in accordance with locally applicable
regulations.
 Insulate the cold water supply line to prevent condensate
forming.
10.1.5 DHW outlet
WARNING Burns
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.
In Australia and New Zealand, observe regulations in
accordance with AS/NZS3500.4:
 Install a tempering device in all systems intended
for personal hygiene.
10.2 Condensate drain
Install a condensate drain hose in order to remove the condensate
which forms.
 Connect the condensate drain bend included in the standard
delivery 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.
Condensate pan heater
!
Material losses
If the temperature at the installation site could continu-
ously fall below freezing (1-2 days) you should install
a condensate pan heater. The condensate pan heater is
not part of the standard delivery.
When the compressor is running, install a load-dependent relay
to switch on the condensate pan heater after a delay.
The condensate pan heater must have an external power supply.
10.3 Power supply
WARNING Electrocution
The connection to the power supply must be in the form
of a permanent connection. Ensure the appliance can
be separated from the power supply by an isolator that
disconnects all poles with at least 3mm contact sepa-
ration. Contactors, mains isolators or fuses can be used
for this. This type of isolator must be installed in the
fixed electrical installation according to the regulations.
For Australia: Ensure the appliance can be separated
from the power supply by a suitable isolator. Contac-
tors, circuit breakers or fuses can be used for this. This
type of isolator must be installed in accordance with the
wiring rules.
WARNING Electrocution
Carry out all electrical connection and installation work
in accordance with national and regional regulations.
WARNING Electrocution
Ensure that the appliance is earthed.
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 inside the appliance.
Prevent the power supply from being switched on while
you are working on the system.

ENGLISH
www.stiebel-eltron.com WWK222-302 H | 15
INSTALLATION
Installation
WARNING Electrocution
Insufficient earthing can lead to electrocution. Ensure
the appliance is earthed according to locally applicable
requirements.
WARNING Electrocution
If the power cable is faulty, replace it with a new one.
The power cable should only be replaced by a qualified
contractor.
!
Material losses
The specified voltage must match the mains voltage. Ob-
serve the type plate.
!
Material losses
Observe the MCB/fuse protection required for the appli-
ance (see chapter "Specification/ Data table").
!
Material losses
Never connect the appliance to the power supply before
the DHW cylinder is filled.
The appliance is supplied with a flexible power cable without plug.
 If the power cable is not long enough, unclamp it from the
appliance. Use a suitable installation cable.
 When routing the new power cable, ensure that it is water-
proof as it passes through the existing cable grommet. Con-
nect the connecting cable properly inside the appliance.
10.3.1 Standard connection (without external signal
transmitter)
X0
2
L
L
N
N
PE
PE
L
N
PE GNYE
BU
BK
1
1
2
X3
2
3
3
1
1
2
D0000050560
BK black
BU blue
GNYE green/yellow
10.3.2 Separate power supply to the impressed current anode
At the factory, the appliance is fitted with rechargeable batteries
that ensure the power supply to the impressed current anode in
the case of a power failure. If regular interruptions to the power
supply are not anticipated, the batteries will require no mainte-
nance.
Every three years the batteries must be replaced for the impressed
current anode in the following cases:
- The impressed current anode is not connected separately to
a continuous power supply source and a switching contact
regularly interrupts the power supply to the appliance.
- The security of supply is inadequate.
Neglecting to do this puts the appliance at risk of damage.
Replacing the batteries can be avoided by connecting the im-
pressed current anode separately to a continuous power sup-
ply source. This continues to protect the DHW cylinder against
corrosion if the rest of the appliance is switched off, e.g. when
connected to a controlled power supply.
 Remove the appliance cover (see chapter “Cleaning and
maintenance/ Removing the appliance cover”).
D0000056083
12
1 Strain relief
2 Terminal X0
 Prepare the electric cables in such a way that each cable ter-
minates with a wire ferrule.
 Push the cables through one of the cable entries in the appli-
ance casing.
 Route leads through the strain relief.
 Remove the jumper which leads from X0/N to X0/2 in the de-
livered condition.
 Remove the jumper which leads from X0/L to X0/1 in the de-
livered condition.

16 | WWK222-302 H www.stiebel-eltron.com
INSTALLATION
Installation
X0
2
L
L
N
N
PE
PE
L
N
PE GNYE
BU
BK
1
1
2
X3
2
3
3
1
1
2
L1 / L2 / L3
N
A
B
D0000055663
A Power supply provided by power supply utility or energy
management system for switching the load (compressor)
B Power supply for the impressed current anode and the
electronics
BK black
BU blue
GNYE green/yellow
 Connect the electric cables for the separate impressed cur-
rent anode power supply to X0/1 and X0/2.
10.3.3 Connection with external signal transmitter
Note
This type of connection must only be carried out by a
qualified electrician.
Note
The appliance has a second and higher set temperature
preselected at the factory. This is activated in the event
of an external switching signal. Set temperature2 takes
priority over the standard set temperature while there is
an external switching signal.
An external signal transmitter for switching a separate set DHW
temperature (set temperature2) can be connected to terminal
X3/1-2. In the delivered condition, terminal X3/1-2 is not assigned.
If this terminal is connected at the voltage stated in the specifica-
tion (see "Permissible voltage range, external signal transducer")
(L to X3/1, N to X3/2), the appliance activates set temperature2.
Following a one-off activation (signal is present for at least 1min-
ute), set temperature2 applies for at least 20minutes. Set temper-
ature2 is ranked higher than set temperature1. 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:
- Water temperature = 61°C
- Set temperature 1 = 60°C
- Set temperature 2 = 65°C
A
1
00510 15 20 25 30 35 40 45 50 55 60 65 70 75 t [min]
B11
0 2
0510 15 20 25 30 35 40 45 50 55 60 65 70 75 t [min]
D0000034613
A External signal
B Compressor
1 20 min. minimum runtime, set temperature2
2 20 min. minimum compressor idle time
 Remove the appliance cover (see chapter "Cleaning and
maintenance/ Removing the appliance cover").
D0000056083
12
1 Strain relief
2 Terminal X3
 Prepare the electric cables in such a way that each cable ter-
minates with a wire ferrule.
 Push the cables through one of the cable entries in the appli-
ance casing.

ENGLISH
www.stiebel-eltron.com WWK222-302 H | 17
INSTALLATION
Installation
 Route leads through the strain relief.
 Connect the cables to X3.
Example 1: Power-OFF signal with its own phase
X0
2
L
L
N
N
PE
PE
L
N
PE GNYE
BU
BK
1
1
2
X3
2
3
3
1
1
2
L1 / L2 / L3
N
EVU
D0000056185
EVU power supply utility
BK black
BU blue
GNYE green/yellow
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 contact closes or opens if certain limits are
exceeded or undershot (inverter output level).
If necessary, check with the inverter manufacturer wheth-
er the product meets the stated criteria.
X0
2
L
L
N
N
PE
PE
L
N
PE GNYE
BU
BK
1
1
2
X3
2
3
3
1
1
2
1
D0000056184
1 Inverter (floating contact)
BK black
BU blue
GNYE green/yellow
The inverter power feed is typically located at a central distribution
point (e.g. in the main fuse box).
10.4 Assembling the appliance
Note
Refit the appliance cover after completing your work. See
chapter "Maintenance and cleaning/ Fitting the appliance
cover").

18 | WWK222-302 H www.stiebel-eltron.com
INSTALLATION
Commissioning
11. Commissioning
11.1 Initial start-up
Note
Fill the DHW cylinder before switching on the power sup-
ply to the appliance.
In case the appliance is energised with an empty DHW
cylinder, it is equipped with boil-dry protection that will
prevent it from operating.
Note
Following an interruption of the power supply, the com-
pressor operation remains blocked for at least one min-
ute, during which the appliance goes through its initial-
ising process.
If the compressor subsequently fails to start, it may be
blocked by additional safety devices (motor overload
relay, high pressure switch). This block can last from 1
to 10 minutes.
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
In the delivered condition, the appliance is set to a DHW temper-
ature >60°C.
 Switch the mains power ON.
Note
Following an interruption of the power supply, the com-
pressor operation remains blocked for at least one min-
ute, during which the appliance goes through its initial-
ising process.
If the compressor subsequently fails to start, it may be
blocked by additional safety devices (motor overload
relay, high pressure switch). This block can last from 1
to 10 minutes.
 Check the function of the appliance.
 Check the function of the safety assembly.
11.1.3 Appliance handover
 Explain the appliance function to users and familiarise them
with its operation.
 Make the user aware of potential dangers, especially the risk
of scalding.
 Make users aware of critical environmental factors and re-
quirements concerning the installation site.
 Inform users that water may drip from the safety valve dur-
ing the heat-up process.
 Please note that the appliance is not protected against frost
and corrosion when it is disconnected from the power sup-
ply. At the factory, the appliance is fitted with rechargeable
batteries that ensure the power supply to the impressed cur-
rent anode in the case of a power failure. The batteries must
be replaced by a qualified contractor every three years, if the
power supply is regularly interrupted by a switching contact
or the security of supply is inadequate. A maintenance con-
tract is recommended for replacing the batteries.
 If the power supply is regularly interrupted by a switching
contact or the security of supply is inadequate, we recom-
mend a maintenance contract for replacing the batteries.
 Hand over these operating and installation instructions to
users for safe-keeping.
11.2 Recommissioning
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 (motor overload relay
and high pressure switch). This block can last from 1 to
10 minutes.
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.
12. Shutdown
!
Material losses
If you disconnect the appliance from the power supply, it
is no longer protected against frost or corrosion.
 Only disconnect the appliance from the power sup-
ply for longer periods if you are also draining the
DHW cylinder. See chapter "Maintenance/ Draining
the appliance".
The appliance can only be switched off by interrupting the power
supply.
 Disconnect the appliance from the mains at the MCB/fuse in
the fuse box.

ENGLISH
www.stiebel-eltron.com WWK222-302 H | 19
INSTALLATION
Troubleshooting
13. Troubleshooting
WARNING Electrocution
Troubleshooting work must only be carried out by a
qualified contractor. 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 or corrosion.
 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").
Fault Cause  Remedy
No hot water is
available.
The impressed current
anode is faulty.
Replace the impressed current
anode.
The compressor
switches off un-
expectedly.
The application limits
have been exceeded or
undershot.
No action required.
Excessive pressure in the
refrigerant circuit. The
safety pressure limiter
has responded 5 times in
5 hours. The compressor
has been switched off.
Eliminate the cause of the
increase in pressure in the
refrigerant circuit. Wait ap-
prox.5-15minutes for the appli-
ance to equalise the pressure.
The appliance can only be un-
blocked using a service program-
ming unit.
The heating
output of the
appliance has
reduced.
An inadequate air flow
across the evaporator is a
possible cause.
Check whether the fan is contam-
inated. Check whether the evap-
orator is contaminated. Ensure
that the supply and extract air
flow are unimpeded.
13.1 Resetting the safety pressure limiter
The safety pressure limiter shuts down if the pressure inside the
refrigerant circuit exceeds the permissible maximum value. If the
safety pressure limiter responds 5 times in 5 hours, the compres-
sor operation will be blocked.
 Eliminate the cause of the increase in pressure in the refrig-
erant circuit
 Wait approx.5-15minutes for the appliance to equalise the
pressure.
The appliance can only be unblocked using a service program-
ming unit.
13.2 Resetting the high limit safety cut-out (only
WWKH)
If the DHW cylinder is overheated, the high limit safety cut-out
switches off the electric emergency/booster heater to protect the
appliance.
D0000039352
1
1 Reset button for high limit safety cut-out
 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.
13.3 Motor overload relay
The motor overload relay will shut down the compressor in the
case of excessive thermal load.
 Remove the cause.
After a short cooling period, the motor overload relay will restart
the compressor automatically.

20 | WWK222-302 H www.stiebel-eltron.com
INSTALLATION
Maintenance
14. Maintenance
WARNING Electrocution
Prior to all work on the appliance, isolate it from the
power supply.
14.1 Removing the appliance cover
D0000040621
 Undo the screw (Torx) that attaches the fascia to the
appliance.
 Push the fascia upwards.
D0000040622
 Carefully remove the fascia.
 Undo the plug-in connection in the electrical cable that runs
to the battery pack on the back of the fascia.
 Carefully lift away the appliance cover and undo the earth
cable that runs from the terminal strip to the cover.
Note
Refit the appliance cover after completing your work. See
chapter "Maintenance and cleaning/ Fitting the appliance
cover").
14.2 Removing the casing ring
Note
If you require more space to work inside the appliance,
you can remove the casing ring 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 ring.
 Remove the condensate drain bend and pipe collar of the
drain. Turn anti-clockwise to undo them.
!
Material losses
Inside the appliance, an earth cable is connected to the
casing ring. Undo the earth cable in order to be able to
remove the casing ring.
D0000034814
The casing ring overlaps along the joint. A tab on one end clips
into the recess at 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
protective clothing, especially safety gloves.
In order to maintain the appliance performance at its best, check
and clean the appliance evaporator as often as necessary.