STIEBEL ELTRON PEO 18 Instruction Manual

OPERATION AND INSTALLATION
OPERACIÓN E INSTALACIÓN
OBSLUHA A INSTALACE
OBSŁUGA I INSTALACJA
РАКУВАЊЕ И ИНСТАЛАЦИЈА
ЭКСПЛУАТАЦИЯ И УСТАНОВКА
Electronically controlled instantaneous water heater | Calentador instantáneo con regulación
electrónica | Elektronicky regulovaný průtokový ohřívač| Elektronicznie regulowany przepływowy
ogrzewacz wody | Електронски регулиран проточен бојлер | Проточный водонагреватель с
электронным управлением
» PEO 18/21/24
» PEO 27
Made in Germany

2| PEO 18/21/24 | PEO 27 www.stiebel-eltron.com
CONTENTS | SPECIAL INFORMATION
SPECIAL INFORMATION
OPERATION
1. General information������������������������������������������3
1.1 Safety instructions ����������������������������������������������� 3
1.2 Other symbols in this documentation������������������������ 3
1.3 Units of measurement ������������������������������������������ 3
2. Safety ����������������������������������������������������������4
2.1 Intended use������������������������������������������������������ 4
2.2 General safety instructions������������������������������������� 4
2.3 Test symbols ������������������������������������������������������ 4
3. Appliance description ����������������������������������������4
4. Settings��������������������������������������������������������5
5. Cleaning, care and maintenance ����������������������������5
6. Troubleshooting ����������������������������������������������5
INSTALLATION
7. Safety ����������������������������������������������������������6
7.1 General safety instructions������������������������������������� 6
7.2 Instructions, standards and regulations ��������������������� 6
8. Appliance description ����������������������������������������6
8.1 Standard delivery ������������������������������������������������ 6
9. Preparations ��������������������������������������������������6
9.1 Installation site ��������������������������������������������������� 6
9.2 Water installation ������������������������������������������������ 7
10. Installation ����������������������������������������������������7
10.1 Standard installation �������������������������������������������� 7
10.2 Installation options ��������������������������������������������� 10
10.3 Completing the installation ����������������������������������� 12
11. Commissioning ��������������������������������������������� 12
11.1 Initial start-up ��������������������������������������������������� 12
11.2 Recommissioning ����������������������������������������������� 13
12. Shutdown ��������������������������������������������������� 13
13. Troubleshooting �������������������������������������������� 13
14. Maintenance ������������������������������������������������ 14
15. Specification ������������������������������������������������ 14
15.1 Dimensions and connections ��������������������������������� 14
15.2 Wiring diagram�������������������������������������������������� 15
15.3 DHW output ������������������������������������������������������ 15
15.4 Application areas/ conversion table ������������������������ 15
15.5 Pressure drop���������������������������������������������������� 16
15.6 Fault conditions ������������������������������������������������� 16
15.7 Details on energy consumption ������������������������������ 16
15.8 Data table �������������������������������������������������������� 17
GUARANTEE
ENVIRONMENT AND RECYCLING
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.
- Risk of scalding: The tap can reach temperatures
in excess of 60°C.
- Ensure the appliance can be separated from the
power supply by an isolator that disconnects all
poles with at least 3mm contact separation.
- Secure the appliance as described in chapter "In-
stallation/ Installation".
- Observe the maximum permissible pressure (see
chapter "Specification/ Data table").
- Drain the appliance as described in chap-
ter "Installation/ Maintenance/ Draining the
appliance".

OPERATION
General information
www.stiebel-eltron.com PEO 18/21/24 | PEO 27| 3
ENGLISH
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 in-
jury 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-serious
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 environmental
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 other-
wise.
!
!

OPERATION
Safety
4| PEO 18/21/24 | PEO 27 www.stiebel-eltron.com
2. Safety
2.1 Intended use
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.
This pressurised appliance is suitable for heating domestic hot
water or for reheating preheated water. The appliance can supply
one or more draw-off points.
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
CAUTION Burns During operation, the tap can reach temperatures in ex-
cess of 60 °C.
There is a risk of scalding at outlet temperatures in excess
of 43°C.
CAUTION Burns If operating with preheated water, e.g. from a solar ther-
mal system, the DHW temperature may vary from the se-
lected set temperature.
!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 appli-
ance. Children must never clean the appliance or perform
user maintenance unless they are supervised.
Where children or persons with limited physical, sensory or men-
tal abilities are allowed to use this appliance, we recommend a
permanent temperature limit. A qualified contractor can set the
limit for you.
!Material losses
The user should protect the appliance and its tap against
frost.
2.3 Test symbols
See type plate on the appliance.
3. Appliance description
The electronically controlled instantaneous water heater with au-
tomatic output matching keeps the outlet temperature constant
up to the output limit. The temperature is then selected via the
draw-off tap.
Heating system
The bare wire heating system has a pressure-tested plastic casing.
The heating system is suitable for hard and soft water areas and is
largely insusceptible to scale build-up. This heating system ensures
rapid and efficient DHW availability.
Note The appliance is equipped with an air detector that largely
prevents damage to the heating system. If, during op-
eration, air is drawn into the appliance, the appliance
shuts down for one minute, thereby protecting the heating
system.

OPERATION
Settings
www.stiebel-eltron.com PEO 18/21/24 | PEO 27| 5
ENGLISH
4. Settings
The DHW outlet temperature can be variably adjusted. The selected
temperature is displayed. At temperatures over 43°C, the colour of
the display changes from blue to red to indicate a risk of scalding.
D0000041609
 Turn the temperature selector to the required temperature.
Note If the outlet temperature is not sufficiently high when the
draw-off valve is fully open and the temperature selector
is set to maximum, then more water is flowing through
the appliance than can be heated by the heating system
(appliance is at its output limit).
 Reduce the water volume at the draw-off valve.
Recommended setting for operation with a thermostatic valve
Set the temperature at the appliance to the maximum temperature.
Following an interruption to the water supply
!Material losses
Following an interruption of the water supply the appli-
ance must be recommissioned by carrying out the follow-
ing steps, in order to prevent the destruction of the bare
wire heating system.
 Disconnect the appliance from the power supply by
removing the fuses/tripping the MCBs.
 Open the tap for one minute until the appliance and
its upstream cold water inlet line are free of air.
 Switch the mains power back ON again.
5. Cleaning, care and maintenance
 Never use abrasive or corrosive cleaning agents. A damp cloth
is sufficient for cleaning the appliance.
 Check the taps regularly. Limescale deposits at the tap out-
lets can be removed using commercially available descaling
agents.
6. Troubleshooting
Problem Cause Remedy
The appliance will not
start despite the DHW
valve being fully open.
There is no power. Check the fuses/MCBs in
your fuse box/distribution
panel.
The flow rate is too low.
The aerator in the tap or
the shower head is scaled
up or contaminated.
Clean and/or descale the
aerator or shower head.
Required temperature
>45°C is not achieved.
The water supply has
been interrupted.
Vent the appliance and
the cold water inlet line
(see chapter "Settings").
The cold water inlet tem-
perature is >45°C.
Reduce the cold water
inlet temperature.
If you cannot remedy the fault, notify your qualified contractor.
To facilitate and speed up your enquiry, please provide the serial
number from the type plate (000000-0000-00000):
Nr.: 000000-0000-00000
D0000041614

6| PEO 18/21/24 | PEO 27 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.
!Material losses
Observe the maximum inlet temperature. Higher tem-
peratures may damage the appliance. You can limit the
maximum inlet temperature by installing a central ther-
mostatic valve.
7.2 Instructions, standards and regulations
Note Observe all applicable national and regional regulations
and instructions.
- The IP 25 (hoseproof) rating can only be ensured with a cor-
rectly fitted cable grommet.
- The specific electrical resistance of the water must not fall
below that stated on the type plate. In a linked water net-
work, observe the lowest electrical water resistance (see
chapter "Specification/ Application areas/ Conversion table").
Your water supply utility will advise you of the specific electri-
cal resistance or conductivity of the water.
8. Appliance description
8.1 Standard delivery
The following are delivered with the appliance:
- Wall mounting bracket
- Threaded stud for wall mounting
- Installation template
- 2 twin connectors (cold water with shut-off valve)
- Flat gaskets
- Cable grommet (power cable from above/ below)
- Screws/ rawl plugs for securing the back panel to allow for
water connection on finished walls
For appliance replacement:
- 2 tap extensions
9. Preparations
9.1 Installation site
!Material losses
Install the appliance in a room free from the risk of frost.
 Always install the appliance vertically and near the draw-off
point.
The appliance is suitable for undersink and oversink installation.
Undersink installation
26�02�02�1345
1
2
1 Cold water inlet
2 DHW outlet
Oversink installation
12
26�02�02�1344
1 Cold water inlet
2 DHW outlet
Note  Mount the appliance on the wall. The wall must have
a sufficient load-bearing capacity.

www.stiebel-eltron.com PEO 18/21/24 | PEO 27| 7
ENGLISH
INSTALLATION
Installation
9.2 Water installation
- No safety valve is required.
- Safety valves are not permissible in the DHW pipe.
 Flush the water line thoroughly.
 Ensure that the flow rate for switching on the appliance is
achieved (see chapter "Specification/ Data table", On). If the
flow rate is not achieved, remove the flow limiter (see chapter
"Installation/ Removing the flow limiter").
 Increase the mains water pressure if the required flow rate is
not achieved with the draw-off valve fully opened.
Taps/valves
Use appropriate pressure taps. Open vented taps are not permitted.
Note Never use the shut-off valve in the cold water inlet to
reduce the flow rate. It is intended for shutting off the
appliance.
Permissible water line materials
- Cold water supply line:
Galvanised steel pipe, stainless steel pipe, copper pipe or
plastic pipe
- DHW outlet line:
Pipes made from stainless steel, copper or plastic
!Material losses
If plastic pipework systems are used, take into account the
maximum inlet temperature and the maximum pressure
(see chapter "Specification/ Data table").
Flexible water connection lines
 If the appliance is installed with flexible water connection
lines, ensure that the pipe bends with bayonet fittings do not
become twisted inside the appliance.
 Secure the back panel at the bottom with two additional
screws.
10. Installation
10.1 Standard installation
- Electrical connection from above; installation on unfinished
walls
- Water connection on unfinished walls
- PEO 18/21/24: medium connected load is preset
For further installation options, see chapter "Alternative installation
methods":
- Electrical connection from below on unfinished walls
- Electrical connection on finished walls
- Connecting a load shedding relay
- Water installation on finished walls
- Water connection on unfinished walls for appliance
replacement
- Operation with preheated water
- Temperature limit
Opening the appliance
D0000041615
 Open the appliance by releasing the snap lock.
NT
T-
so
X1
26�02�02�0762
 Remove the back panel by pressing the two locking hooks and
pulling the base part of the back panel forwards.

8| PEO 18/21/24 | PEO 27 www.stiebel-eltron.com
INSTALLATION
Installation
Preparing the power cable
160
≥ 30
26�02�02�0887
Fitting the wall mounting bracket
26�02�02�0972
 Mark out the holes for drilling using the installation template.
If the appliance is to be installed with water connections on
finished walls, also mark out the fixing holes in the lower part
of the template.
 Drill the holes and secure the wall mounting bracket with
2screws and 2rawl plugs (screws and rawl plugs are not part
of the standard delivery).
 Fit the threaded stud provided.
 Fit the wall mounting bracket.
Fitting the cable grommet
26�02�02�0950
 Fit the cable grommet. For connecting cables >6mm², en-
large the hole in the cable grommet.
Making the water connection
!Material losses
Carry out all water connection and installation work in
accordance with regulations.
26�02�02�0948
 Seal and insert the twin connectors.
!Material losses
Never use the shut-off valve in the cold water inlet to
reduce the flow rate.
Preparing the back panel
!Material losses
If you break open the wrong knock-out in the back panel
by mistake, you must use a new back panel.
LLL
D0000041893
 Break out the relevant cable grommet knock-out in the back
panel. Deburr any sharp edges with a file if necessary.

www.stiebel-eltron.com PEO 18/21/24 | PEO 27| 9
ENGLISH
INSTALLATION
Installation
Installing the appliance
LLL
3
L3’
4
L2’
1
L1’
2
LLL
MV
NT C
T- soll
X1 1
D0000041894
 Push the back panel over the threaded stud and the cable
grommet. Pull the cable grommet by the locking hooks into
the back panel using pliers, until both locking hooks audibly
click into place.
 Remove the protective transport plugs from the water
connections.
 Press the back panel firmly into place and lock the fixing tog-
gle by turning it clockwise through 90°.
D0000041925
 Screw the water connection pipes with flat gaskets onto the
twin connectors.
!Material losses
The strainer must be fitted for the appliance to function.
 When replacing an appliance, check whether the
strainer is installed (see chapter "Maintenance").
Removing the flow limiter
!Material losses
If you use a thermostatic valve, the flow limiter must not
be removed.
L1’
2
LLL
X11
26�02�02�0771
2
1
1 Plastic profile washer
2 Flow limiter
 Remove the flow limiter and refit the plastic profile washer.
Making the electrical connection
WARNING Electrocution Carry out all electrical connection and installation work
in accordance with relevant regulations.
WARNING Electrocution The connection to the power supply must be in the form of
a permanent connection in conjunction with the remova-
ble cable grommet. Ensure the appliance can be separated
from the power supply by an isolator that disconnects all
poles with at least 3mm contact separation.
WARNING Electrocution Ensure that the appliance is earthed.
!Material losses
Observe the type plate. The specified voltage must match
the mains voltage.
 Connect the power cable to the mains terminal (see chapter
"Specification/ Wiring diagram").

10 | PEO 18/21/24 | PEO 27 www.stiebel-eltron.com
INSTALLATION
Installation
PEO 18/21/24: Re-plugging the coding card
In its delivered condition, the appliance is set to 21kW. When
changing to a different connected load, carry out the following
steps:
D0000047341
 Re-plug the coding card according to the selected connected
load (for selectable connected load and fuse protection of the
appliance, see chapter "Specification/ Data table").
 Tick the selected connected load on the type plate. Use a ball-
point pen to do this.
Fitting the base part of the back panel
3
L3’
4
L2’
1
L1’
2
LLL
NT C
T- sol l
X11
26�02�02�1348
 Position the lower back panel on the main back panel and
click it into place.
 Align the mounted appliance by loosening the fixing toggle,
aligning the power supply and back panel, and then re-tight-
ening the fixing toggle. If the back panel is not flush with the
wall, the appliance can be secured at the bottom with two
additional screws.
10.2 Installation options
10.2.1 Electrical connection from below on unfinished walls
1
L1í
2
LLL
X11
26�02�02�0767
 Fit the cable grommet.
!Material losses
If you break open the wrong knock-out in the back panel
by mistake, you must use a new back panel.
 Break out the relevant cable grommet knock-out in the back
panel. Deburr any sharp edges with a file if necessary.
 Reposition the mains terminal in the appliance from the top
to the bottom.
 Push the back panel over the threaded stud and the cable
grommet. Pull the cable grommet by the locking hooks into
the back panel using pliers, until both locking hooks audibly
click into place.
 Press the back panel firmly into place and lock the fixing tog-
gle by turning it clockwise through 90°.