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°.

www.stiebel-eltron.com PEO 18/21/24 | PEO 27| 11
ENGLISH
INSTALLATION
Installation
10.2.2 Electrical connection on finished walls
Note This type of connection changes the protection rating of
the appliance.
 Change the type plate. Cross out "IP 25" and mark the
box "IP 24". Use a ballpoint pen to do this.
!Material losses
If you break open the wrong knock-out in the back panel
by mistake, you must use a new back panel.
 Cleanly cut or break out the required cable entries in the back
panel (for positions, see chapter "Specification/ Dimensions
and connections"). Deburr any sharp edges with a file if
necessary.
 Route the power cable through the cable grommet and con-
nect it to the mains terminal.
10.2.3 Connecting a load shedding relay
When operating additional electric appliances, such as electric
storage heaters, install a load shedding relay in the distribution
board. The relay responds when the instantaneous water heater
starts.
!Material losses
Connect the phase that switches the load shedding relay
to the indicated terminal of the mains terminal in the
appliance (see chapter "Specification/ Wiring diagram").
10.2.4 Water installation on finished walls
Note This type of connection changes the protection rating of
the appliance.
 Change the type plate. Cross out "IP 25" and mark the
box "IP 24". Use a ballpoint pen to do this.
26�02�02�0765
 Fit water plugs with gaskets to seal the in-wall connection.
 Fit a suitable pressure tap.
26�02�02�1006
 Click the lower section of the back panel into place in the
upper section of the back panel.
 Secure the connection pipes to the appliance.
 Secure the back panel at the bottom with two additional
screws.
!Material losses
If you break open the wrong knock-out in the back panel
by mistake, you must use a new back panel.
 Cleanly break out the knock-outs in the appliance cover. De-
burr any sharp edges with a file if necessary.
 Slide the lower back panel under the connection pipes of the
tap and click the lower back panel into place.
 Secure the connection pipes to the appliance.
10.2.5 Water installation on unfinished walls for appliance
replacement
If the existing twin connectors of the old appliance only protrude
from the wall by approx.16mm, you cannot use the twin connec-
tors provided.
Note With this connection, the cold water supply can only be
shut off within the domestic installation.
16
D0000041634
 Seal and fit the screw-in tap extensions provided.
 Connect the appliance.
10.2.6 Operation with preheated water
You can limit the maximum inlet temperature by installing a central
thermostatic valve.

12 | PEO 18/21/24 | PEO 27 www.stiebel-eltron.com
INSTALLATION
Commissioning
10.2.7 Temperature limit
CAUTION Burns If operating with preheated water, the set temperature
limit and anti-scalding protection may be ineffective.
 In such cases, limit the temperature with an up-
stream central thermostatic valve.
You can set the temperature limit inside the appliance cover to
43°C.
D0000041912
 Switch the temperature limit to 43°C.
The temperature selector enables the temperature to be set to a
value between 30°C and 43°C.
10.3 Completing the installation
 Open the shut-off valve in the twin connector or the cold
water inlet line.
11. Commissioning
WARNING Electrocution Commissioning must only be carried out by a qualified
contractor in accordance with safety regulations.
11.1 Initial start-up
D0000041618
 Open and close all connected draw-off valves several times,
until all air has been purged from the pipework and the
appliance.
 Carry out a tightness check.
 Activate the safety pressure limiter by firmly pressing the reset
button (the appliance is delivered with the safety pressure
limiter deactivated).
 Plug the temperature selector cable plug into the PCB.
 Fit the appliance cover, ensuring it clicks into place. Check that
the appliance cover is seated correctly.
 Switch the mains power ON.
 Check the function of the appliance.

www.stiebel-eltron.com PEO 18/21/24 | PEO 27| 13
ENGLISH
INSTALLATION
Shutdown
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.
 Hand over these instructions.
11.2 Recommissioning
Vent the appliance and the cold water inlet line (see chapter "Set-
tings").
See chapter "Commissioning".
12. Shutdown
 Isolate all poles of the appliance from the power supply.
 Drain the appliance (see chapter "Maintenance").
13. Troubleshooting
WARNING Electrocution To test the appliance, it must be supplied with power.
Indication variants for diagnostic traffic light (LED)
Red Illuminates in the event of a fault
Yellow Illuminates during heating operation
Green Flashing: Appliance is connected to power supply
1
D0000041794
1 Diagnostic traffic light
Fault / LED diagnos-
tic light display
Cause Remedy
The flow rate is too low. The strainer in the appli-
ance is dirty.
Clean the strainer.
The set temperature is not
achieved.
One phase down. Check the fuse/MCB in
your fuse box/distribution
panel.
The heating system does
not switch on.
Air has been detected in
the water and heating
output is briefly switched
off.
The appliance restarts
after one minute.
No hot water and no traf-
fic light display.
The MCB/fuse has re-
sponded/blown.
Check the fuse/MCB in
your fuse box/distribution
panel.
Safety pressure limiter
AP3 has tripped.
Remove the cause of the
fault (e.g. faulty pressure
flush).
Protect the heating sys-
tem against overheating
by opening a draw-off
valve downstream of the
appliance for one minute.
This depressurises and
cools down the heating
system.
Activate the safety
pressure limiter at flow
pressure by pressing the
reset button (see chapter
"Commissioning").
The PCB is faulty. Check the PCB and re-
place if required.
Traffic light display: Green
flashes or constantly on
The PCB is faulty. Check the PCB and re-
place if required.
No hot water at a flow
rate
>2.5l/min.
The flow meter (DFE) is
not plugged in.
Plug the flow meter plug
back in.
The flow meter (DFE) is
faulty.
Check the flow meter and
replace if required.
Traffic light display: Yel-
low constantly on, green
flashing
The high limit safety
cut-out has responded or
suffered a lead break.
Check the high limit safety
cut-out and replace it if
required.
No hot water at a flow
rate
>3l/min.
The heating system is
faulty.
Check the heating system
resistor and replace if
required.
The PCB is faulty. Check the PCB and re-
place if required.
Traffic light display: Yel-
low constantly on, green
flashing
The outlet sensor is un-
plugged or the lead is
broken.
Plug in the outlet sensor
or replace if required.
Traffic light display: Red
constantly on, green
flashing
The cold water sensor is
faulty.
Check the PCB and re-
place if required.
No hot water
Required temperature >
45°C is not achieved.
The cold water inlet tem-
perature exceeds 45°C.
Reduce the cold water
inlet temperature to the
appliance.
Traffic light display: Red
constantly on, green
flashing
The outlet sensor is faulty
(short circuit).
Check the outlet sensor
and replace if required.

14 | PEO 18/21/24 | PEO 27 www.stiebel-eltron.com
INSTALLATION
Maintenance
14. Maintenance
WARNING Electrocution Before any work on the appliance, ensure omnipolar dis-
connection from the power supply.
Draining the appliance
The appliance can be drained for maintenance work.
WARNING Burns Hot water may escape when draining the appliance.
 Close the shut-off valve in the twin connector or the cold
water inlet line.
 Open all draw-off valves.
 Undo the water connections on the appliance.
 Store the dismantled appliance in a room free from the risk
of frost, as water residues remaining inside the appliance can
freeze and cause damage.
Cleaning the strainer
26�02�02�0949
If contaminated, clean the strainer in the threaded cold water fit-
ting. Close the shut-off valve in the cold water inlet line before
removing, cleaning and refitting the strainer.
15. Specification
15.1 Dimensions and connections
395
100
485
325
45
5
93
226
190
50
112
190
35
c01
c06
b02
D0000017757
b02 Entry electrical cables I
c01 Cold water inlet Male thread G 1/2 A
c06 DHW outlet Male thread G 1/2 A
Alternative connection options
325
50
50
35
40
b03
b02
b04
b04
b04
D0000019778
b02 Entry electrical cables I
b03 Entry electrical cables II
b04 Entry electrical cables III

www.stiebel-eltron.com PEO 18/21/24 | PEO 27| 15
ENGLISH
INSTALLATION
Specication
15.2 Wiring diagram
3/PE ~ 380-415 V
85�02�02�0005
1 Heater
2 High limit safety cut-out
3 Safety pressure limiter
Priority control with LR 1-A
85�02�02�0003�
2
1
1 Control cable to the contactor of the 2nd appliance (e.g. elec-
tric storage heater).
2 Control contact opens when switching the instantaneous
water heater on.
15.3 DHW output
The DHW output is subject to the mains voltage, the appliance's
connected load and the cold water inlet temperature. The rated
voltage and rated output can be found on the type plate (see chap-
ter "Troubleshooting").
Connected load in kW 38°C DHW output in l/min.
Rated voltage Cold water inlet temperature
380 V 400 V 415 V 5°C 10°C 15°C 20°C
16.2 7.0 8.3 10.1 12.9
16.3 7.1 8.3 10.1 12.9
18.0 7.8 9.2 11.2 14.3
19.0 8.2 9.7 11.8 15.1
19.4 8.4 9.9 12.0 15.4
21.0 9.1 10.7 13.0 16.7
21.7 9.4 11.1 13.5 17.2
22.6 9.8 11.5 14.0 17.9
23.5 10.2 12.0 14.6 18.7
24.0 10.4 12.2 14.9 19.0
24.4 10.6 12.4 15.2 19.4
25.8 11.2 13.2 16.0 20.5
26.0 11.3 13.3 16.1 20.6
27.0 11.7 13.8 16.8 21.4
Connected load in kW 50°C DHW output in l/min.
Rated voltage Cold water inlet temperature
380 V 400 V 415 V 5°C 10°C 15°C 20°C
16.2 5.1 5.8 6.6 7.7
16.3 5.2 5.8 6.7 7.8
18.0 5.7 6.4 7.3 8.6
19.0 6.0 6.8 7.8 9.0
19.4 6.2 6.9 7.9 9.2
21.0 6.7 7.5 8.6 10.0
21.7 6.9 7.8 8.9 10.3
22.6 7.2 8.1 9.2 10.8
23.5 7.5 8.4 9.6 11.2
24.0 7.6 8.6 9.8 11.4
24.4 7.7 8.7 10.0 11.6
25.8 8.2 9.2 10.5 12.3
26.0 8.3 9.3 10.6 12.4
27.0 8.6 9.6 11.0 12.9
15.4 Application areas/ conversion table
Specific electrical resistance and specific electrical conductivity (see
chapter "Data table").
Standard specifica-
tion at 15°C 20°C 25°C
Resist-
ance
ρ≥
Conductivity σ≤ Resist-
ance
ρ≥
Conductivity σ≤ Resist-
ance
ρ≥
Conductivity σ≤
Ωcm mS/m μS/cm Ωcm mS/m μS/cm Ωcm mS/m μS/cm
900 111 1111 800 125 1250 735 136 1361
1000 100 1000 890 112 1124 815 123 1227
1100 91 909 970 103 1031 895 112 1117
1200 83 833 1070 93 935 985 102 1015
1300 77 769 1175 85 851 1072 93 933

16 | PEO 18/21/24 | PEO 27 www.stiebel-eltron.com
INSTALLATION
Specication
15.5 Pressure drop
Taps/valves
Tap pressure drop at a flow rate of 10 l/min
Mono lever mixer tap, approx. MPa 0.04 - 0.08
Thermostatic valve, approx. MPa 0.03 - 0.05
Hand shower, approx. MPa 0.03 - 0.15
Sizing the pipework
When calculating the size of the pipework, an appliance pressure
drop of 0.1MPa is recommended.
15.6 Fault conditions
In the event of a fault, loads up to a maximum of 95 °C at a pressure
of 1.2MPa can occur temporarily in the installation.
15.7 Details on energy consumption
The product data complies with EU regulations relating to the Di-
rective on the ecological design of energy related products (ErP).
PEO 18/21/24 PEO 27
233991 233992
Manufacturer STIEBEL ELTRON STIEBEL ELTRON
Load profile S S
Energy efficiency class A A
Annual power consumption kWh 477 481
Energy conversion efficiency % 39 39
Default temperature setting °C 60 60
Sound power level dB(A) 15 15
Special information on measuring efficiency Data at Pmax. None

www.stiebel-eltron.com PEO 18/21/24 | PEO 27| 17
ENGLISH
GUARANTEE | ENVIRONMENT AND RECYCLING
15.8 Data table
PEO 18/21/24 PEO 27
233991 233992
Electrical data
Rated voltage V 380 400 415 380 400
Rated output kW 16.2/19/21.7 18/21/24 19.4/22.6/25.8 24.4 27
Rated current A 27.6/29.5/33.3 29/31/35 30.1/32.2/36.3 37.1 39
MCB/fuse rating A 32/32/35 32/32/35 32/32/40 40 40
Phases 3/PE 3/PE
Frequency Hz 50/60 50/60 50/- 50/60 50/60
Specific resistance ρ15 ≥ (at ϑcold ≤25°C) Ω cm 900 900 1000 900 900
Specific conductivity σ15 ≤ (at ϑcold ≤25°C) μS/cm 1111 1111 1000 1111 1111
Specific resistance ρ15 ≥ (at ϑcold ≤45°C) Ω cm 1200 1200 1300 1200 1200
Specific conductivity σ15 ≤ (at ϑcold ≤45°C) μS/cm 833 833 770 833 833
Max. mains impedance at 50Hz Ω 0.284 0.270 0.260 0.254 0.241
Connections
Water connection G 1/2 A G 1/2 A
Application limits
Max. permissible pressure MPa 1 1
Max. inlet temperature for reheating °C 45 45
Values
Max. permissible inlet temperature °C 60 60
On l/min >2.5 >2.5
DHW delivery l/min 9.4/11.0/12.6 14.2
Δϑon delivery K 26 26
Hydraulic data
Nominal capacity l 0.4 0.4
Versions
Temperature setting range °C 30-60 30-60
Safety category 1 1
Insulating block Plastic Plastic
Heating system heat generator Bare wire Bare wire
Cover and back panel Plastic Plastic
Colour White White
IP rating IP25 IP25
Dimensions
Height mm 485 485
Width mm 226 226
Depth mm 93 93
Weights
Weight kg 3.6 3.6
GUARANTEE
ENVIRONMENT AND RECYCLING
Guarantee
The guarantee conditions of our German companies do not
apply to appliances acquired outside of Germany. In countries
where our subsidiaries sell our products a guarantee can only
be issued by those subsidiaries. Such guarantee is only grant-
ed if the subsidiary has issued its own terms of guarantee. No
other guarantee will be granted.
We shall not provide any guarantee for appliances acquired in
countries where we have no subsidiary to sell our products.
This will not aect warranties issued by any importers.
Environment and recycling
We would ask you to help protect the environment. After use,
dispose of the various materials in accordance with national
regulations.

18 | PEO 18/21/24 | PEO 27 www.stiebel-eltron.com
CONTENIDO | INDICACIONES ESPECIALES
INDICACIONES ESPECIALES
OPERACIÓN
1. Indicaciones generales������������������������������������� 19
1.1 Instrucciones de seguridad������������������������������������ 19
1.2 Otras marcas presentes en esta documentación���������� 19
1.3 Unidades de medida ������������������������������������������� 19
2. Seguridad ��������������������������������������������������� 20
2.1 Utilización conforme a las prescripciones������������������ 20
2.2 Instrucciones generales de seguridad ���������������������� 20
2.3 Sello de certificación ������������������������������������������� 20
3. Descripción del aparato������������������������������������ 20
4. Configuración ����������������������������������������������� 21
5. Limpieza, conservación y mantenimiento ���������������� 21
6. Resolución de problemas���������������������������������� 21
INSTALACIÓN
7. Seguridad ��������������������������������������������������� 22
7.1 Instrucciones generales de seguridad ���������������������� 22
7.2 Directivas, normas y disposiciones �������������������������� 22
8. Descripción del aparato������������������������������������ 22
8.1 Ámbito de suministro ������������������������������������������ 22
9. Preparativos������������������������������������������������� 22
9.1 Lugar de montaje ����������������������������������������������� 22
9.2 Instalación de agua��������������������������������������������� 23
10. Montaje������������������������������������������������������ 23
10.1 Montaje estándar ����������������������������������������������� 23
10.2 Alternativas de montaje ��������������������������������������� 26
10.3 Finalizar montaje ����������������������������������������������� 28
11. Puesta en marcha ������������������������������������������ 28
11.1 Primera puesta en marcha������������������������������������ 28
11.2 Nueva puesta en marcha �������������������������������������� 28
12. Puesta fuera de servicio ����������������������������������� 29
13. Localización y reparación de averías ��������������������� 29
14. Mantenimiento���������������������������������������������� 30
15. Especificaciones técnicas ���������������������������������� 30
15.1 Dimensiones y conexiones ������������������������������������ 30
15.2 Esquema de conexiones eléctricas �������������������������� 31
15.3 Rendimiento de agua caliente ������������������������������� 31
15.4 Ámbitos de aplicación/ Tabla de conversión�������������� 31
15.5 Pérdida de presión���������������������������������������������� 32
15.6 Condiciones en caso de avería ������������������������������� 32
15.7 Datos sobre el consumo energético ������������������������� 32
15.8 Tabla de especificaciones�������������������������������������� 33
GARANTÍA
MEDIO AMBIENTE Y RECICLADO
INDICACIONES
ESPECIALES
- El aparato puede ser utilizado por niños a partir
de 8 años, así como por personas con capaci-
dades físicas, sensoriales o mentales limitadas,
o con falta de experiencia y conocimientos, solo
bajo la vigilancia de otra persona o si antes han
recibido instrucciones sobre el uso seguro del
aparato y han comprendido los peligros que
pueden derivarse. No deje que los niños jueguen
con el aparato. Las tareas de limpieza y manteni-
miento propias del usuario no deben ser realiza-
das por niños sin vigilancia.
- Peligro de escaldamiento: Los grifos/válvulas
pueden calentarse a más de 60°C.
- El aparato debe poder desconectarse omnipolar-
mente de la red eléctrica mediante una separa-
ción de al menos 3mm.
- Fije el aparato tal como se describe en el capítulo
"Instalación/ Montaje".
- Tenga en cuenta la presión máxima admisible
(consulte el capítulo "Especificaciones técnicas/
Tabla de especificaciones").
- Vacíe el aparato tal y como se describe en el ca-
pítulo "Instalación/ Mantenimiento/ Vaciado del
aparato".

OPERACIÓN
Indicaciones generales
www.stiebel-eltron.com PEO 18/21/24 | PEO 27| 19
ESPAÑOL
OPERACIÓN
1. Indicaciones generales
Los capítulos "Indicaciones especiales" y "Operación" están dirigi-
dos al usuario del aparato y al profesional técnico especializado.
El capítulo "Instalación" está dirigido al profesional técnico espe-
cializado.
Nota Lea atentamente estas instrucciones antes del uso y ar-
chívelas en un lugar seguro.
Si entrega este aparato a otros usuarios, no olvide incluir
las instrucciones.
1.1 Instrucciones de seguridad
1.1.1 Estructura de las instrucciones de seguridad
!PALABRA DE ADVERTENCIA Tipo de peligro
Mediante este tipo de palabras se explican las posibles
consecuencias en caso de desobedecimiento de las ins-
trucciones de seguridad.
 Aquí se proponen las medidas necesarias para evitar
el peligro.
1.1.2 Símbolos, tipo de peligro
Símbolo Tipo de peligro
Lesión
Electrocución
Quemaduras
(quemaduras, escaldadura)
1.1.3 Palabras de advertencia
PALABRA DE
ADVERTENCIA
Significado
PELIGRO Indicaciones cuyo desobedecimiento tiene como consecuen-
cia lesiones graves o la muerte.
ADVERTENCIA Indicaciones cuyo desobedecimiento puede tener como con-
secuencia lesiones graves o la muerte.
PRECAUCIÓN Indicaciones cuyo desobedecimiento puede tener como con-
secuencia lesiones de gravedad media o baja.
1.2 Otras marcas presentes en esta documentación
Nota Las indicaciones generales se señalizan mediante el sím-
bolo adyacente.
 Lea atentamente las indicaciones.
Símbolo Significado
Daños materiales
(daños en el aparato, indirectos, medioambientales)
Eliminación del aparato
 Este símbolo le indica que usted tiene que hacer algo. Se des-
criben paso a paso las medidas necesarias.
1.3 Unidades de medida
Nota Si no se indica lo contrario, todas las dimensiones estarán
expresadas en milímetros.
!
!

OPERACIÓN
Seguridad
20 | PEO 18/21/24 | PEO 27 www.stiebel-eltron.com
2. Seguridad
2.1 Utilización conforme a las prescripciones
El aparato está previsto para utilizarse en un ámbito doméstico.
Personas no instruidas lo pueden manejar de forma segura. El
aparato puede utilizarse igualmente en ámbitos que no sean do-
mésticos, como en pequeñas empresas, siempre que se maneje
del mismo modo.
El aparato a presión sirve para calentar agua potable o para re-
calentar agua previamente calentada. El aparato puede alimentar
uno o varios puntos de dispensado.
Cualquier otro uso distinto al aquí previsto se considera un uso
indebido. Se considera uso previsto el cumplimiento de estas ins-
trucciones, así como las instrucciones de los accesorios utilizados.
2.2 Instrucciones generales de seguridad
PRECAUCIÓN Quemaduras Los grifos/válvulas pueden calentarse durante el funcio-
namiento a más de 60°C.
A temperaturas de salida superiores a 43°C existe peligro
de escaldamiento.
PRECAUCIÓN Quemaduras La temperatura del agua caliente puede ser distinta de la
temperatura de referencia ajustada en un funcionamiento
con agua precalentada; p. ej., un sistema de calefacción
solar.
!ADVERTENCIA Lesiones
El aparato puede ser utilizado por niños a partir de 8
años, así como por personas con capacidades físicas, sen-
soriales o mentales limitadas, o con falta de experiencia
y conocimientos, solo bajo la vigilancia de otra persona
o si antes han recibido instrucciones sobre el uso seguro
del aparato y han comprendido los peligros que pueden
derivarse. No deje que los niños jueguen con el apara-
to. Las tareas de limpieza y mantenimiento propias del
usuario no deben ser realizadas por niños sin vigilancia.
En caso de que niños u otras personas con capacidades físicas, sen-
soriales o mentales limitadas utilicen el aparato, recomendamos
una limitación de temperatura permanente. La limitación puede
realizarla un profesional técnico especializado.
!Daños materiales
El usuario debe proteger el aparato y los grifos/válvulas
frente a la formación de escarcha.
2.3 Sello de certificación
Véase placa de especificaciones técnicas en el aparato.
3. Descripción del aparato
El calentador instantáneo con regulación electrónica con adapta-
ción automática de la potencia mantiene constante la temperatura
de salida hasta el límite de rendimiento. Posteriormente, la tem-
peratura se selecciona mediante la grifería de dispensado.
Sistema de calefacción
El sistema de calefacción de cables desnudos tiene una capa de
plástico estanca a la presión. El sistema de calefacción es apto
para agua tanto pobre como rica en cal, ya que es resistente a
la acumulación de cal. El sistema de calefacción abastece agua
caliente de forma rápida y eficaz.
Nota El aparato está equipado con un sistema de detección de
aire que evita que se produzcan daños en el sistema de
calefacción. Si durante el funcionamiento entra aire en el
aparato, el aparato desconectará la potencia de calefac-
ción durante un minuto, con lo que protegerá el sistema
de calefacción.