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STIEBEL ELTRON DHB 18 STi Operating And Installation

DHB 21 STi\ DHB 27 STi\ DHB 24 STi

Made by: STIEBEL ELTRON
Type: Operating And Installation
Category: Water Heater
Pages: 18
Size: 4.48 MB

 

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BEDIENUNG UND INSTALLATION
OPERATING AND INSTALLATION
UTILISATION ET INSTALLATION
GEBRUIK EN INSTALLATIE
OBSŁUGA I INSTALACJA
OBSLUHA A INSTALACE
HASZN

Á

LATI 

É

S TELEP

Í

T

É

SI 

Ú

TMUTAT

Ó

UPRAVLJANJE IN NAMESTITEV

Elektronisch gesteuerter Durchlauferhitzer | Electronically controlled 
instantaneous water heater | Chauffe-eau instantan

é à gestion électronique 

| Elektronisch gestuurde elektrische doorstromer | Elektronicznie sterowany 
przepływowy ogrzewacz wody | Elektronicky 

řízený průtokový ohřívač | Elektromos 

vez

érlésű átfolyós vízmelegítő | Elektronsko krmiljen pretočni grelnik

 

» DHB 18 STi

 

» DHB 21 STi

 

» DHB 24 STi

 

» DHB 27 STi


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18

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CoNTeNTS | SPeCIAL INforMATIoN 

 

 

SPECIAL INFORMATION

OPERATION

1. 

General information ��������������������������������������� 19

1.1 

Safety instructions ���������������������������������������������� 19

1.2 

Other symbols in this documentation ���������������������� 19

1.3 

Units of measurement ����������������������������������������� 19

2. 

Safety �������������������������������������������������������� 19

2.1 

Intended use ����������������������������������������������������� 19

2.2 

General safety instructions ����������������������������������� 19

2.3 

Test symbols ����������������������������������������������������� 19

3. 

Appliance description ������������������������������������� 20

4. 

Operation ��������������������������������������������������� 20

4.1 

Recommended settings ��������������������������������������� 20

5. 

Cleaning, care and maintenance ������������������������� 20

6. 

Troubleshooting �������������������������������������������� 20

INSTALLATION

7. 

Safety �������������������������������������������������������� 21

7.1 

General safety instructions ����������������������������������� 21

7.2 

Instructions, standards and regulations ������������������� 21

8. 

Appliance description ������������������������������������� 21

8.1 

Standard delivery ����������������������������������������������� 21

8.2 

Accessories ������������������������������������������������������� 21

9. 

Preparations ������������������������������������������������ 22

9.1 

Installation site �������������������������������������������������� 22

9.2 

Water installation ����������������������������������������������� 22

10. 

Installation �������������������������������������������������� 23

10.1  Standard installation ������������������������������������������� 23

11. 

Commissioning ��������������������������������������������� 25

11.1  Initial start-up ��������������������������������������������������� 25
11.2  Recommissioning ����������������������������������������������� 25

12. 

Shutdown ��������������������������������������������������� 25

13. 

Alternative installation options ��������������������������� 25

13.1  Electrical connection from above on unfinished walls �� 25
13.2  Electrical connection on finished walls �������������������� 26
13.3  Large conductor cross-section for electrical 

connection from below ���������������������������������������� 26

13.4  Connecting a load shedding relay ��������������������������� 26
13.5  Water installation on finished walls ������������������������ 26
13.6  Water installation on finished walls with brazing / 

compression fitting ��������������������������������������������� 27

13.7  Water installation on finished walls; fitting the 

appliance cover ������������������������������������������������� 27

13.8  Installation of lower back panel with threaded fittings 

on finished walls ������������������������������������������������ 27

13.9  Wall mounting bracket when replacing an appliance ��� 27
13.10  Installation with offset tiles ����������������������������������� 27
13.11  Pivoting appliance cover �������������������������������������� 28

14. 

Troubleshooting �������������������������������������������� 29

15. 

Maintenance ������������������������������������������������ 30

16. 

Specification ������������������������������������������������ 30

16.1  Dimensions and connections ��������������������������������� 30
16.2  Wiring diagram ������������������������������������������������� 30
16.3  DHW output ������������������������������������������������������ 31
16.4  Application areas / conversion table ����������������������� 31
16.5  Pressure drop ��������������������������������������������������� 31
16.6  Fault conditions ������������������������������������������������� 31
16.7  Country-specific approvals and certifications: Germany 31
16.8  Details on energy consumption ������������������������������ 32
16.9  Data table �������������������������������������������������������� 32

GUARANTEE

ENVIRONMENT AND RECYCLING

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.

 

- Risk of burns: the tap can reach temperatures in 

excess of 55 °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 "Installation / Specification / Data table").

 

- Drain the appliance as described in chapter "In-

stallation / Maintenance / Draining the appliance". 


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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.

f

f

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.

f

f

Read these texts carefully.

Symbol

Meaning

 

 

Material losses 

(appliance damage, consequential losses and environmen-

tal pollution)

 

 

Appliance disposal 

 

f

f

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 appliance is intended for heating domestic hot water and can 

supply one or more draw-off points.
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

 

CAUTION Burns

During operation, the tap can reach temperatures in ex-

cess of 55 °C.

There is a risk of scalding at outlet temperatures in ex-

cess of 43 °C.

!

 

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.

!

 

Material losses

The user should protect the appliance and its tap against 

frost.

2.3  Test symbols

See type plate on the appliance.

!

!


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oPerATIoN 

 

Appliance description

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3.  Appliance description

You can adjust the DHW outlet temperature via the temperature 

selector. From a flow rate of approx. 3 l/min and above, the control 

unit regulates the correct heating output, subject to the tempera-

ture setting and cold water temperature.

Heating system

The bare wire heating system has a pressure-tested plastic casing. 

The heating system is suitable for (both) soft and hard water and 

is largely resistant to scale build-up. This heating system ensures 

rapid and efficient DHW availability.

 

Note

The appliance is equipped with an air detector that large-

ly 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 heat-

ing system.

4.  Operation

The DHW outlet temperature can be adjusted in 3 stages.

26

�0

2�

02

�0

95

1

1

2

3

1  Hand wash basin (approx. 35 °C)

2  Shower / bath (approx. 45 °C)

3  Kitchen sink (approx. 55 °C)

f

f

Turn the temperature selector to the required position.

Should the outlet temperature fail to reach the required level with 

the tap fully open and the temperature selector set to maximum, 

then more water is flowing through the appliance than can be 

heated by the heating element.

f

f

Reduce the flow rate at the tap.

4.1  Recommended settings

Thermostatic valve

If you operate the appliance with a thermostatic valve, we rec-

ommend that you set the temperature on the appliance to the 

maximum level (kitchen sink). You can then select the required 

temperature using the thermostatic valve.

Following an interruption of the water supply

!

 

Material losses

To ensure that the bare wire heating system is not dam-

aged following an interruption to the water supply, the 

appliance must be restarted in the following sequence.

f

f

Disconnect the appliance from the power supply by 

removing the fuses/tripping the MCBs.

f

f

Open the tap for one minute until the appliance and 

its upstream cold water inlet line are free of air.

f

f

Switch the mains power back ON again.

5.  Cleaning, care and maintenance

f

f

Never use abrasive or corrosive cleaning agents. A damp 

cloth is sufficient for cleaning the appliance.

f

f

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/distribu-

tion panel.

 

 

 

The aerator in the tap 

or the shower head is 

scaled up or contami-

nated.

Clean and/or descale the 

aerator or shower head. 

 

 

 

 

 

 

The water supply has 

been interrupted. 

 

 

 

Vent the appliance and 

the cold water supply line 

(see chapter "Operation / 

Recommended settings / 

Following an interruption 

to the water supply").

Whilst hot water is being 

drawn off, initially cold 

water flows for a short 

period.

The air sensor detects air 

in the water and briefly 

switches the heater off. 

The appliance restarts 

automatically after 

1 minute. 

If you cannot remedy the fault, notify your qualified contractor. 

To facilitate and speed up your request, provide the number from 

the type plate (000000-0000-000000).

D

00000

51

86

6

DHB ... STi

 


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INSTALLATIoN 

 

Safety

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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 functioning and operational reliabil-

ity only if original accessories and spare parts intended for the 

appliance are used.

!

 

Material losses

Observe the maximum permissible inlet temperature (see 

chapter "Installation / Specification / Data table"). Higher 

temperatures may damage the appliance. You can limit 

the inlet temperature by means of a central thermostatic 

valve (see chapter "Installation / Appliance description / 

Accessories").

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, factor in the lowest electrical resistance of the water 

(see chapter "Installation / Specification / Data table"). Your 

water supply utility will advise you of the specific electrical 

water resistance or conductivity.

8.  Appliance description

8.1  Standard delivery

The following are delivered with the appliance:

 

- Wall mounting bracket

 

- Installation plate

 

- 2 twin connectors

 

- Cold water 3-way ball shut-off valve

 

- DHW tee

 

- Flat gaskets

 

- Strainer

 

- Flow limiter

 

- Plastic profile washer

 

- Plastic connection pieces / installation aid

 

- Cover guides

8.2  Accessories

Taps

 

- MEKD mono lever kitchen pressure tap

 

- MEBD mono lever bath pressure tap

Plug G ½ A

If you use pressure taps on finished walls other than those rec-

ommended in the accessories, please use plugs.

Installation set for finished walls

 

- Brazing fitting - copper pipe for brazed connection Ø 12 mm

 

- Compression fitting - copper pipe

 

- Compression fitting - plastic pipe (suitable for Viega: San-

fix-Plus or Sanfix-Fosta)

Universal mounting frame

 

- Mounting frame with electrical connections

Pipe assembly for undersink appliances

You will need the undersink installation set if you make the water 

connections (G ⅜ A) at the top of the appliance.

Pipe assembly for offset installation

You will need this pipe assembly set if you intend to offset the 

appliance by 90 mm downwards from the water connection.

Pipe assembly for replacing a gas water heater

You will need this pipe assembly set if the existing installation 

has gas water heater connections (cold water connection on the 

left-hand side, DHW connection on the right-hand side).

Pipe assembly DHB water plug-in couplings

Use the water plug-in couplings if the existing installation has 

water plug-in connections from an instantaneous water heater.

Load shedding relay (LR 1-A)

The load shedding relay for installation in the distribution board 

provides priority control for the instantaneous water heater when 

other appliances, such as electric storage heaters, are being op-

erated simultaneously.


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INSTALLATIoN 

 

Preparations

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9.  Preparations

9.1  Installation site

!

 

Material losses

Install the appliance in a room free from the risk of frost.

f

f

Always install the appliance vertically and near the draw-off 

point.

The appliance is suitable for undersink and oversink installations.

Undersink installation

1

2

26

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2�

02

�0

84

4

1  Cold water Inlet

2  DHW outlet

Oversink installation

2

1

26

�0

2�

02

�0

84

5

1  Cold water Inlet

2  DHW outlet

 

Note

f

f

Mount the appliance on the wall. The wall must have 

a sufficient load-bearing capacity.

9.2  Water installation

 

- A safety valve is not required.

 

- Never operate with preheated water.

f

f

Flush the water line thoroughly.

Taps

Use suitable pressure taps/valves (see chapter "Installation  / 

Appliance description / Accessories"). Open vented taps are not 

permitted.

 

Note

Never use the 3-way ball shut-off valve in the cold water 

inlet to reduce the flow rate. The 3-way ball shut-off valve 

is intended to shut off the appliance.

Permissible water line materials

 

- Cold water inlet line: 

Pipes made from galvanised steel, stainless steel, copper or 

plastic

 

- DHW outlet line: 

Pipes made from stainless steel, copper or plastic

!

 

Material losses

If plastic pipework is used, take into account the max-

imum inlet temperature and the maximum permissible 

pressure (see chapter "Installation / Specification / Data 

table").

Flow rate

f

f

Ensure that the flow rate for switching on the appliance is 

achieved (see chapter "Installation / Specification / Data 

table", On).

f

f

Increase the water line pressure if the required flow rate is 

not achieved when the draw-off valve is fully open. If the 

flow rate is not reached despite increasing the pressure, re-

move the flow limiter and install the plastic profile washer.

2

1

26

�0

2�

02

�0

82

0

1  Flow limiter

2  Plastic profile washer

 

Note

For the thermostatic valve to function correctly, the flow 

limiter must not be replaced with the plastic profile wash-

er.


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INSTALLATIoN 

 

Installation

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10.  Installation

Standard installation

 

- Electrical connection from below on unfinished walls

 

- Water connection on unfinished walls

For further installation options, see chapter "Installation / 

Installation options":

 

- Electrical connection from above on unfinished walls

 

- Electrical connection on finished walls

 

- Large conductor cross-section for electrical connection from 

below

 

- Connecting a load shedding relay

 

- Water installation on finished walls

 

- Water installation on finished walls with brazing / compres-

sion fitting

 

- Water installation on finished walls; fitting the appliance 

cover

 

- Installation of lower back panel with threaded fittings on fin-

ished walls 

 

- Wall mounting bracket when replacing an appliance

 

- Installation with offset tiles

 

- Pivoting appliance cover

10.1  Standard installation

Opening the appliance

26

�0

2�

02

�0

86

4

f

f

Open the appliance by pulling the flap downwards, undo the 

screw and lift up the appliance cover.

26

�02

�02

�1

10

1

f

f

Remove the back panel by pressing the two locking hooks 

and pulling the lower section of the back panel forwards.

Preparing the power cable

160

30

1

26

�0

2�

02

�0

82

4�

1  Installation aid

f

f

Prepare the power cable.

Fitting the wall mounting bracket

26

�0

2�

02

�0

81

0�

f

f

Mark out the holes for drilling using the installation plate. 

If the appliance is to be installed with water connections on 

finished walls, also mark out a fixing hole in the lower part 

of the template.

f

f

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).

f

f

Fit the wall mounting bracket.

Making the water connection

!

 

Material losses

Carry out all water connection and installation work in 

accordance with regulations.

12

D

00000

53

31

9

f

f

Seal and insert the twin connectors.


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INSTALLATIoN 

 

Installation

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D

00000

50

94

7

1

4

5

2

3

2

1  DHW with tee

2  Gasket

3  Cold water with 3-way ball shut-off valve

4  Strainer

5  Flow limiter or plastic profile washer (see chapter "Installa-

tion / Water installation / Flow rate")

f

f

Secure the tee and 3-way ball shut-off valve, each with a flat 

gasket, to the twin connectors.

!

 

Material losses

Never use the 3-way ball shut-off valve in the cold water 

inlet to reduce the flow rate.

Installing the appliance

26

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2�

02

�0

81

1

f

f

For easy installation, push the cable grommet of the upper 

electrical connection into the back panel from behind.

f

f

Remove the transport plugs from the water connections.

f

f

Remove the fixing toggle from the upper part of the back 

panel.

f

f

Route the power cable through the cable grommet from 

behind until the power cable rests against the cable sheath. 

Align the power cable.  

Enlarge the hole in the cable grommet if the cross-section of 

the power cable is > 6 mm².

f

f

Push the appliance over the threaded stud of the wall mount-

ing bracket, so that it breaks through the soft seal. If neces-

sary, use a screwdriver.

f

f

Push the fixing toggle on to the threaded stud of the wall 

mounting bracket.

f

f

Push the back panel firmly against the wall. Lock the fixing 

toggle by turning it 90° clockwise.

26

�0

2�

02

�0

85

8

f

f

Fit the pipes with flat gaskets onto the twin connectors.

!

 

Material losses

The strainer must be fitted for the appliance to function.

f

f

When replacing an appliance, check whether the 

strainer is installed.

f

f

Open the 3-way ball shut-off valve or the shut-off valve in the 

cold water supply line.

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 re-

movable cable grommet. Ensure the appliance can be 

separated from the power supply by an isolator that dis-

connects 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.

f

f

Connect the power cable to the mains terminal (see chapter 

"Installation / Specification / Wiring diagrams").


background image

INSTALLATIoN 

 

Commissioning

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25

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ISH

Fitting the lower back panel

26

�02

�02

�1

102

f

f

Fit the lower back panel into the back panel. Click the lower 

back panel into place.

f

f

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 of the appliance is 

not flush, you can secure the appliance at the bottom with an 

additional screw.

11.  Commissioning

 

WARNING Electrocution

Commissioning may only be carried out by a qualified 

contractor in accordance with safety regulations.

11.1  Initial start-up

≥ 60 s

D

00000

51

87

7

f

f

Open and close all connected draw-off valves several times, 

until all air has been purged from the pipework and the 

appliance.

f

f

Carry out a tightness check.

f

f

Activate the safety pressure limiter under flow pressure by 

firmly pressing in the reset button (the appliance is delivered 

with the safety pressure limiter disabled).

f

f

Plug the set value transducer cable plug into the PCB.

f

f

Fit the appliance cover. Check that the appliance cover is 

seated correctly.

f

f

Secure the appliance cover with the screw.

f

f

Switch the mains power ON.

f

f

Calibrate the temperature. Turn the temperature selector 

fully clockwise then fully anti-clockwise.

f

f

Remove the protective foil from the control fascia.

f

f

Check the function of the appliance.

Appliance handover

f

f

Explain the appliance function to users and familiarise them 

with its operation.

f

f

Make the user aware of potential dangers, especially the risk 

of scalding. 

f

f

Hand over these instructions.

11.2  Recommissioning

!

 

Material losses

To ensure that the bare wire heating system is not dam-

aged following an interruption to the water supply, the 

appliance must be restarted in the following sequence.

f

f

Disconnect the appliance from the power supply by 

removing the fuses/tripping the MCBs.

f

f

Open the tap for one minute until the appliance and 

its upstream cold water inlet line are free of air.

f

f

Switch the mains power back ON again.

12.  Shutdown

f

f

Isolate all poles of the appliance from the power supply.

f

f

Drain the appliance (see chapter "Installation / Maintenance / 

Draining the appliance").

13.  Alternative installation options

13.1  Electrical connection from above on unfinished 

walls

26

�02

�02

�1

12

3�

f

f

Cut open the cable grommet for the power cable.

f

f

Push down the locking hook to secure the mains terminal. 

Pull out the mains terminal.


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INSTALLATIoN 

 

Alternative installation options

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f

f

Reposition the mains terminal from the bottom to the top. 

Secure the mains terminal by pushing it under the locking 

hook.

26

�02

�02

�1

30

6�

f

f

Lay the control wires below the wire guide.

13.2  Electrical connection on finished walls

 

Note

This type of connection changes the protection rating of 

the appliance.

f

f

Change the type plate. Cross out "IP 25" and mark 

the box "IP 24". Please use a ballpoint pen to do this.

!

 

Material losses

If you break out the wrong knock-out by mistake, use a 

new back panel.

f

f

Cleanly cut or break out the required cable entries in the 

back panel (for positions, see chapter "Installation / Specifi-

cation / Dimensions and connections"). Deburr sharp edges 

with a file if necessary.

f

f

Route the power cable through the cable grommet and con-

nect the power cable to the mains terminal.

13.3  Large conductor cross-section for electrical 

connection from below

If you use cables with a large cross-section, you can fit the cable 

grommet after the appliance has been installed.

1.

3.

4.

2.

26

�02

�02

�1

12

4�

f

f

Before installing the appliance, use a screwdriver to push out 

the cable grommet.

f

f

Slide the cable grommet over the power cable. Use the 

installation aid supplied in the standard delivery. If the 

cross-section is > 6 mm², enlarge the hole in the cable 

grommet. 

f

f

Push the cable grommet into the back panel. Engage the 

cable grommet in position.

13.4  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 ap-

pliance (see chapter "Installation / Specification / Wiring 

diagrams").

13.5  Water installation on finished walls

 

Note

This type of connection changes the protection rating of 

the appliance.

f

f

Change the type plate. Cross out "IP 25" and mark 

the box "IP 24". Please use a ballpoint pen to do this.

D

00000

33

10

4

f

f

Fit water plugs with gaskets to seal the connection on unfin-

ished walls. All taps listed under "Accessories" are supplied 

with plugs and gaskets as part of their standard delivery. For 

pressure taps other than those we recommend, plugs and 

gaskets can be ordered as "Accessories".

f

f

Fit a suitable pressure tap.

f

f

Push the lower part of the back panel under the connecting 

pipes of the tap and push it into the back panel.

f

f

Fit the connection pipes together with the tee and 3-way ball 

shut-off valve.


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INSTALLATIoN 

 

Alternative installation options

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13.6  Water installation on finished walls with 

brazing / compression fitting

You can connect copper or plastic pipes with "solder fittings" or 

"compression fittings" (accessories).
With "solder fittings" with threaded connection for 12 mm copper 

pipes, proceed as follows:

f

f

Push the union nuts over the connection pipes.

f

f

Braze the inserts to the copper pipes.

f

f

Push the lower part of the back panel under the connecting 

pipes of the tap and push it into the back panel.

f

f

Fit the connection pipes together with the tee and 3-way ball 

shut-off valve.

 

Note

Observe the tap manufacturer's instructions.

13.7  Water installation on finished walls; fitting the 

appliance cover

1

2

3

26

�0

2�

02

�0

52

5

1  Cover guides

2  Pipe aperture

3  Screw

f

f

Cleanly break out the knock-outs in the appliance cover. If 

necessary, use a file.

f

f

Click the cover guides into place in the knock-outs.

f

f

Secure the back panel at the bottom with a screw.

f

f

If you use flexible water connection pipes, please pre-

vent pipe bends from twisting (bayonet connections in the 

appliance).

13.8  Installation of lower back panel with threaded 

fittings on finished walls

If using threaded connections for finished walls, the lower part of 

the back panel can also be installed after fitting the taps/valves. 

To do this, carry out the following steps:

f

f

With a saw, cut open the lower section of the back panel.

f

f

Fit the lower section of the back panel by bending it out at 

the sides and guiding it over the pipes.

f

f

Insert the connection pieces into the lower section of the 

back panel from behind.

f

f

Click the lower section of the back panel into place.

f

f

Secure the lower section of the back panel with a screw.

2

1

3

26

�0

2�

02

�1

08

0

1  Back panel bottom section

2  Connection pieces delivered in the pack

3  Screw

13.9  Wall mounting bracket when replacing an 

appliance

An existing STIEBEL ELTRON wall mounting bracket may be used 

when replacing appliances (except instantaneous water heater 

DHF).

f

f

Break through the back panel of the appliance for the thread-

ed stud on the installed wall mounting bracket.

Replacing instantaneous water heater DHF

26

�0

2�

02

�0

81

5�

f

f

Reposition the threaded stud on the wall mounting bracket 

(the stud has a self-tapping thread).

f

f

Rotate the wall mounting bracket 180° and mount it on the 

wall (the DHF logo is then turned towards the reader).

13.10 Installation with offset tiles

11

0

20

26

�02

�02

�1

06

6�

2

1

1  Minimum contact area of the appliance

2  Maximum tile offset

f

f

Adjust the wall clearance. Lock the back panel in place using 

the fixing toggle (turn through 90° clockwise).


background image

INSTALLATIoN 

 

Alternative installation options

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13.11 Pivoting appliance cover

The appliance cover can be rotated for undersink installation.

26

�0

2�

02

�0

86

5

f

f

Remove the programming unit from the appliance cover by 

undoing the screws.

f

f

Turn the appliance cover (not the appliance) and refit the 

programming unit.

f

f

Plug the set value transducer cable into the PCB (see chapter 

"Installation / Commissioning / Initial start-up").

f

f

Hook the appliance cover in at the top. Swivel the appliance 

cover down onto the back panel and press it until it engages 

audibly. 

f

f

Secure the appliance cover.


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INSTALLATIoN 

 

Troubleshooting

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14.  Troubleshooting

 

WARNING Electrocution

To test the appliance, it must be supplied with power.

Possible indications of diagnostic traffic light (LeD)

Red

Illuminates in the event of a fault

Yellow

Illuminates during heating mode

Green

Flashing: Appliance is supplied with mains power

fault / diagnostic traffic light LeD

Cause

remedy

 

The appliance does not start. 

The shower head / aerators are scaled up. 

Descale or if necessary replace the shower head / 

aerators.

 

The flow rate is too low.

The strainer in the appliance 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 heater switches off. 

The air detector senses air in the water. Heating output 

cuts out temporarily.

The appliance restarts after one minute. 

No hot water and no traffic light display.

The MCB/fuse has responded/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 system against overheating by 

opening a draw-off valve downstream from the ap-

pliance for one minute. This depressurises and cools 

down the heating system.

 

 

 

 

Activate the safety pressure limiter at flow pressure 

by pressing the reset button, also see chapter "In-

stallation / Commissioning / Initial start-up".

 

 

The PCB is faulty.

Check the PCB and replace if necessary.

 

Traffic light display: Green flashing 

No hot water at flow rate  

> 3 l/min.

Flow sensor DFE is not plugged in. 

 

Re-insert the flow sensor plug. 

 

  

Flow sensor DFE is faulty. 

Check the flow sensor and replace if necessary. 

The set temperature is not achieved. 

The set value transducer or connecting cable is faulty, or 

the connecting cable is not attached.

Attach the connecting cable; replace the set value 

transducer if required.

 

 

Temperature limiting is enabled.

Disable temperature limiting.

Traffic light display: Yellow constantly on; green 

flashing 

No hot water at flow rate  

> 3 l/min.

The high limit safety cut-out has responded or its lead 

is broken.

Check the high limit safety cut-out and replace if 

necessary.

The heating system is faulty. 

Check the resistance of the heater and replace if 

necessary.

 

 

The PCB is faulty.

Check the PCB and replace if necessary.

 

Traffic light display: Yellow constantly on; green 

flashing 

Set temperature not reached.

Appliance is operating at its output limit. 

 

Reduce the flow rate. Install the flow limiter. 

 

Traffic light display: Red constantly on; green 

flashing 

No hot water

The cold water sensor is faulty. 

 

Check the PCB and replace if necessary. 

 

   Required temperature > 35 °C not reached 

The cold water inlet temperature exceeds 45 °C. 

Reduce the cold water inlet temperature to the ap-

pliance.


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INSTALLATIoN 

 

Maintenance

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15.  Maintenance

 

WARNING Electrocution

Before any work on the appliance, disconnect it omnip-

olar from the power supply.

Draining the appliance

The appliance can be drained for maintenance work.

 

WARNING Scalding

Hot water may escape when you drain the appliance.

f

f

Close the 3-way shut-off valve or the shut-off valve in the 

cold water supply line.

f

f

Open all draw-off valves.

f

f

Undo the water connections on the appliance.

f

f

If dismantled, store the appliance in a room free from the 

risk of frost, as water residues remaining inside the appli-

ance can freeze and cause damage.

Cleaning the strainer

If contaminated, clean the strainer in the threaded cold water 

fitting. Close the 3-way shut-off valve or the shut-off valve in the 

cold water supply line before removing, cleaning and refitting 

the strainer.

16.  Specification

16.1  Dimensions and connections

b02

c01

c06

47

0

100

41

4

40

110

20

225
140

35

35

121

36

8

30

D

00000

51

85

7

 

 

DHB STi

b02  Entry cables I

 

 

c01  Cold water Inlet

Male thread

G 1/2 A

c06  DHW outlet

Male thread

G 1/2 A

Alternative connection options

165

50

44

30

35

72

325

338

47

b03

b02

b04

b04

b04

b04

b04

D

00000

19

21

2

 

DHB STi

b02  Entry cables I

 

b03  Entry cables II

 

b04  Entry cables III

 

16.2  Wiring diagram

3/PE ~ 380-415 V

85

�0

2�

02

�0

00

5

1  Heater

2  High limit safety cut-out

3  Safety pressure limiter


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INSTALLATIoN 

 

Specification

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Priority control with LR 1-A

85

�0

2�

02

�0

00

3�

2
1

1  Control cable to the contactor of the second appliance (elec-

tric storage heater for example).

2  Control contact opens when switching the instantaneous 

water heater on.

16.3  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 

chapter "Operation / 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

 

 

28.0

12.1

14.3

17.4

22.2

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

 

 

28.0

8.9

10.0

11.4

13.3

16.4  Application areas / conversion table

Specific electrical resistance and specific electrical conductivity 

(see chapter "Installation / 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

1100

91 

909

970

103 

1031

895

112 

1117

1200

83

833

1070

93

935

985

102

1015

16.5  Pressure drop

Taps

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

Shower head, 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.

16.6  Fault conditions

In case of faults, loads up to a maximum of 95 °C at a pressure of 

1.2 MPa can occur temporarily in the installation.

16.7  Country-specific approvals and certifications: 

Germany

A general test certificate as verification of suitability regarding 

noise emissions has been issued for this appliance, based on the 

State Building Regulations [Germany].

DIN 4109

PA-IX 6816/I


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INSTALLATIoN 

 

Specification

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16.8  Details on energy consumption

Product data complies with EU regulations relating to the Directive 

on the ecodesign of energy-related products (ErP).

 

 

DHB 18 STi

DHB 21 STi

DHB 24 STi

DHB 27 STi

 

 

227612

227613

227614

227615

Versions
Manufacturer

 

STIEBEL ELTRON

STIEBEL ELTRON

STIEBEL ELTRON

STIEBEL ELTRON

Default temperature setting

°C

55

55

55

55

Special information on measuring efficiency

 

None

None

None

None

Output data
Load profile

 

S

S

S

S

Energy data
Energy efficiency category

 

A

A

A

A

Annual power consumption

kWh

480

477

475

475

Energy efficiency

%

39

39

39

39

Sound data
Sound power level

dB(A)

15

15

15

15

16.9  Data table

 

 

DHB 18 STi

DHB 21 STi

DHB 24 STi

DHB 27 STi

 

 

227612

227613

227614

227615

Electrical details
Rated voltage

V

380

400

415

380

400

415

380

400

415

380

400

415

Rated output

kW

16.2

18

19.4

19

21

22.6

21.7

24

25.8

23.5

26

28

Rated current

A

24.7

26

27

29.5

31

32.2

33.3

35

36.3

35.6

37.7

38.9

Fuse

A

25

25

32

32

32

32

35

35

40

35

40

40

Phases

 

3/PE

3/PE

3/PE

3/PE

Frequency

Hz 50/60 50/60

50/- 50/60 50/60

50/- 50/60 50/60

50/-

50/-

50/-

50/-

Max. mains impedance at 50Hz

Ω

0.379

0.360

0.347

0.325 0.308

0.297

0.284

0.270

0.260

0.254

0.241

 

Specific resistance ρ

15

 ≥ (at 

ϑ

cold ≤35 °C)

Ω cm ≥1100 ≥1100 ≥1200 ≥1100 ≥1100 ≥1200 ≥1100 ≥1100 ≥1200 ≥1100 ≥1100 ≥1200

Specific conductivity 

σ

15 

≤ (at 

ϑ

cold ≤35 °C)

μS/cm

≤910

≤910

≤830

≤910

≤910

≤830

≤910

≤910

≤830

≤910

≤910

≤830

Connections
Water connection

 

G 1/2 A

G 1/2 A

G 1/2 A

G 1/2 A

Application limits
Max. permissible pressure

MPa

1

1

1

1

Values
Max. permissible inlet temperature

°C

35

35

35

35

ON

l/min

> 3.0

> 3.0

> 3.0

> 3.0

Flow rate for pressure drop

l/min

5.2

6.0

6.9

7.7

Pressure drop at flow rate 

MPa 

0.08 (0.06 without 

DMB)

0.1 (0.08 without DMB)  0.13 (0.1 without DMB) 

0.16 (0.12 without 

DMB)

Flow rate limit at

l/min

7.5

7.5

8.5

8.5

DHW delivery

l/min

9.2

10.7

12.3

13.8

Δ

ϑ

 at DHW delivery

K

28

28

28

28

Hydraulic data
Rated capacity

l

0.4

0.4

0.4

0.4

Versions
Temperature adjustment

°C

Approx. 35, 45, 55

Approx. 35, 45, 55

Approx. 35, 45, 55

Approx. 35, 45, 55

Protection class

 

1

1

1

1

Insulation block

 

Plastic

Plastic

Plastic

Plastic

Heating system heat generator

 

Bare wire

Bare wire

Bare wire

Bare wire

Cap and back panel

 

Plastic

Plastic

Plastic

Plastic

Colour

 

white

white

white

white

IP rating

 

IP25

IP25

IP25

IP25

Dimensions
Height

mm

470

470

470

470

Width

mm

225

225

225

225

Depth

mm

110

110

110

110

Weights
Weight

kg

3.6

3.6

3.6

3.6


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www.stiebel-eltron.com 

DHB  STi | 

33

EN

GL

ISH

GUARANTEE | ENVIRONMENT AND RECYCLING 

 

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 affect 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.


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Deutschland 

STIEBEL ELTRON GmbH & Co. KG 

Dr.-Stiebel-Straße 33 | 37603 Holzminden 

Tel. 05531 702-0 | Fax 05531 702-480 

info@stiebel-eltron.de 

www.stiebel-eltron.de 

Verkauf

 

Tel. 05531 702-110 | Fax 05531 702-95108 | info-center@stiebel-eltron.de 

Kundendienst

 

Tel. 05531 702-111 | Fax 05531 702-95890 | kundendienst@stiebel-eltron.de 

Ersatzteilverkauf

  Tel. 05531 702-120 | Fax 05531 702-95335 | ersatzteile@stiebel-eltron.de 

Irrtum und technische Änderungen vorbehalten! | Subject to errors and technical changes! | Sous réserve 
d‘erreurs et de modifications techniques! | Onder voorbehoud van vergissingen en technische wijzigingen! | 
Salvo error o modificación técnica! | Excepto erro ou alteração técnica | Zastrzeżone zmiany techniczne i 
ewentualne błędy | Omyly a technické změny jsou vyhrazeny! | A muszaki változtatások és tévedések jogát 
fenntartjuk! |

Отсутствие ошибок не гарантируется. Возможны технические изменения.

 | Chyby a 

technické zmeny sú vyhradené! 

Stand 9046

 

Australia 

STIEBEL ELTRON Australia Pty. Ltd. 

6 Prohasky Street | Port Melbourne VIC 3207 

Tel. 03 9645-1833 | Fax 03 9645-4366 

info@stiebel.com.au 

www.stiebel.com.au 

Austria 

STIEBEL ELTRON Ges.m.b.H. 

Eferdinger Str. 73 | 4600 Wels 

Tel. 07242 47367-0 | Fax 07242 47367-42 

info@stiebel-eltron.at 

www.stiebel-eltron.at 

Belgium 

STIEBEL ELTRON bvba/sprl 

't Hofveld 6 - D1 | 1702 Groot-Bijgaarden 

Tel. 02 42322-22 | Fax 02 42322-12 

info@stiebel-eltron.be 

www.stiebel-eltron.be 

China 

STIEBEL ELTRON (Guangzhou) Electric 

Appliance Co., Ltd. 

Rm 102, F1, Yingbin-Yihao Mansion, No. 1 

Yingbin Road 

Panyu District | 511431 Guangzhou 

Tel. 020 39162209 | Fax 020 39162203 

info@stiebeleltron.cn 

www.stiebeleltron.cn 

Czech Republic 

STIEBEL ELTRON spol. s r.o. 

K Hájům 946 | 155 00 Praha 5 - Stodůlky 

Tel. 251116-111 | Fax 235512-122 

info@stiebel-eltron.cz 

www.stiebel-eltron.cz 

Finland 

STIEBEL ELTRON OY 

Kapinakuja 1 | 04600 Mäntsälä 

Tel. 020 720-9988 

info@stiebel-eltron.fi 

www.stiebel-eltron.fi 

France 

STIEBEL ELTRON SAS 

7-9, rue des Selliers 

B.P 85107 | 57073 Metz-Cédex 3 

Tel. 0387 7438-88 | Fax 0387 7468-26 

info@stiebel-eltron.fr 

www.stiebel-eltron.fr 

Hungary 

STIEBEL ELTRON Kft. 

Gyár u. 2 | 2040 Budaörs 

Tel. 01 250-6055 | Fax 01 368-8097 

info@stiebel-eltron.hu 

www.stiebel-eltron.hu 

Japan 

NIHON STIEBEL Co. Ltd. 

Kowa Kawasaki Nishiguchi Building 8F 

66-2 Horikawa-Cho 

Saiwai-Ku | 212-0013 Kawasaki 

Tel. 044 540-3200 | Fax 044 540-3210 

info@nihonstiebel.co.jp 

www.nihonstiebel.co.jp 

Netherlands 

STIEBEL ELTRON Nederland B.V. 

Daviottenweg 36 | 5222 BH 's-Hertogenbosch 

Tel. 073 623-0000 | Fax 073 623-1141 

info@stiebel-eltron.nl 

www.stiebel-eltron.nl 

Poland 

STIEBEL ELTRON Polska Sp. z O.O. 

ul. Działkowa 2 | 02-234 Warszawa 

Tel. 022 60920-30 | Fax 022 60920-29 

biuro@stiebel-eltron.pl 

www.stiebel-eltron.pl 

Russia 

STIEBEL ELTRON LLC RUSSIA 

Urzhumskaya street 4, 

building 2 | 129343 Moscow 

Tel. 0495 7753889 | Fax 0495 7753887 

info@stiebel-eltron.ru 

www.stiebel-eltron.ru 

Slovakia 

TATRAMAT - ohrievače vody s.r.o. 

Hlavná 1 | 058 01 Poprad 

Tel. 052 7127-125 | Fax 052 7127-148 

info@stiebel-eltron.sk 

www.stiebel-eltron.sk 

Switzerland 

STIEBEL ELTRON AG 

Industrie West 

Gass 8 | 5242 Lupfig 

Tel. 056 4640-500 | Fax 056 4640-501 

info@stiebel-eltron.ch 

www.stiebel-eltron.ch 

Thailand 

STIEBEL ELTRON Asia Ltd.  

469 Moo 2 Tambol Klong-Jik 

Amphur Bangpa-In | 13160 Ayutthaya 

Tel. 035 220088 | Fax 035 221188 

info@stiebeleltronasia.com 

www.stiebeleltronasia.com  

United Kingdom and Ireland 

STIEBEL ELTRON UK Ltd. 

Unit 12 Stadium Court 

Stadium Road | CH62 3RP Bromborough 

Tel. 0151 346-2300 | Fax 0151 334-2913 

info@stiebel-eltron.co.uk 

www.stiebel-eltron.co.uk 

United States of America 

STIEBEL ELTRON, Inc. 

17 West Street | 01088 West Hatfield MA 

Tel. 0413 247-3380 | Fax 0413 247-3369 

info@stiebel-eltron-usa.com 

www.stiebel-eltron-usa.com 

A 283362-38950-9074

283036-38680-9047 M

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