Installation Instructions; Structure; Special Fittings; Important Instructions - STIEBEL ELTRON DHB 12 si Instructions For Use And Installation

2. Installation instructions

Structure

1 Power selector switch
2 Shower comfort switch
3 Cover cap (cover securing screw)
3 a Short operating instructions (inside)
4 Cover
5 Lower part of the back plate
6 Hot water connection
7 Cold water connection (3-way cut-off)
8 Fastening screw assembly support
(service)
9 Upper part of the back plate
10 Terminal block
11 Safety pressure limiter (AD 3)
11 a Reset button for safety pressure limiter
(in the event of a fault)
12 Differential pressure switch/flow
regulator MRS
13 Heating system
14 Fastening screw
15 System pressure switch
16 Toothed bar
17 Setting lever
18 Lower part of device fixing assembly
19 Electricity supply concealed in lower
area of device
20 Electricity supply concealed in upper
area of device
21 Device fixing point for replacement
against DHA
22 Device fixing point on top in new
installation
23 Dimension for installation, "wall flush
fitting"
24 Fixing holes for replacing third-party
products
25 Knurled nut for rear wall alignment in
the event of tiles being uneven
26 Knock-out point for fitting bracket
provided with DHB 12-27 Si and for
installed DHB and DHF fitting bracket in
the event of replacement
27 Knock-out point for installed fitting
bracket of Stiebel Eltron DHE
28 Engagement hooks for lower part of
rear wall
29 Connection line
30-32 Connection of priority circuit
33 Blanking plugs
34 Cable grommet

Special fittings

(Special instructions for mono-bloc mixers
and thermostat fittings)
Mono-bloc mixers and thermostat fittings
must be suitable for hydraulically-controlled
instantaneous water heaters (take note of
the manufacturer's instructions).
Shower heads with low pressure losses are
to be provided for.
Mono-bloc mixers:
– The flow pressure when operating with
mono-bloc mixers, for example with
DHB 21, should be at least 3 bar.
With low flow pressure:
– Power selector switch at position
– Shower comfort switch in latching position
(greatest temperature increase). The
flow pressure is considered sufficient when
a water temperature of less than 35 °C can
be set at the fitting without any problems.
12
for the qualified installer
Thermostat fitting:
See page 11 for instructions.
Important information
Air in the cold water pipe will
destroy the bare-wire heating system
of the DHB. If the water supply to the
DHB has been interrupted, for example
due to the risk of frost or work on the
water pipe, the following steps must be
carried out before the system is used again:
1. Disconnect supply or disconnect the
fuses.
2. Open a hot water tap downstream of
the device for as long as is necessary
for the device and the cold water pipe
to be freed of air.
3. Reconnect the supply or connect the
fuses again.
– The device is suitable for hot water
production (potable supply), and is to
be installed in enclosed, frost-free
rooms, as close as possible to the
outlet point (uninstalled devices are to
be stored in a frost-free place, because
there will always be residual water left
in the unit).
– All information in these Instructions for
Use and Installation must be followed
carefully. They provide important
information with regard to safety,
operation, installation, and maintenance
of the device.

Short description

The Stiebel Eltron DHB instantaneous water
heater is a hydraulically-controlled pressure
device for heating cold water in accordance
with DIN 1988, with which one or more
outlet points can be supplied.
The flow regulator (MRS), which can be
adjusted by means of the shower comfort
switch:
– keeps the flow volume constant in the
event of pressure fluctuations in the
water mains, and therefore keeps the
output temperature constant;
– limits the flow volume (latching position)
and therefore guarantees, even in winter,
an adequate temperature increase.
The integrated installation pressure switch
(15) allows for installation with DVGW-
tested plastic pipes. In the event of a fault,
the integrated installation pressure switch
with the downstream plastic pipe installation
will be loaded with a pressure of 12 bar.
The bare-wire heating system is enclosed
within a pressure-resistant copper sheathing.
The heating system is especially suitable for
hard water, i.e. containing lime (for areas of
operation see Table 2).
Regulations and
specifications
– The installation (water and electrical
installation) and the first-time operation
and maintenance of this device may only
be carried out by a qualified installer, in
accordance with these instructions.
– Regulations of the local energy supply
company
– Specifications of the water supply company
concerned
– Fit the device with the lower section flush
with the wall (respect dimension
110 mm (23)). Also secure the device at
the bottom (18).
Other points to be noted:
– The device rating plate
– Technical data:
The specific electrical resistance of the
water must not be less than that indicated
on the device rating plate. With a water
mains network, the lowest electrical
resistance of the water is to be taken into
account (see table 2). You can find out the
specific electrical resistance or electrical
conductivity of the water from the water
supply company.
Operation with pre-heated water of more
than 25 °C is not permitted.
– Accompanying pipe heating (trace heating)
is not permitted.
– Material of the water installation:
Cold water pipe:
Steel, copper, or plastic pipes
– Operating conditions in accordance with
DIN 1988, Part 2, December 1988, Section
2.2.3, Table 1.
Hot water pipe:
Copper
Plastic piping systems:
The integrated installation pressure switch
allows for installation with DVGW-tested
plastic pipes. To determine the suitability of
plastic piping systems in conjunction with
the DHB, the following instructions are to
be adhered to:
The operating conditions apply as per
DIN 1988, Part 2, December 1988, Section
2.2.3, Table 1.
Respect the instructions provided by the
plastic pipe manufacturer.
– Electrical connection only to a permanent
connection.
– Fittings:
Fittings for open devices are not permitted.
– Safety fittings:
A safety valve is not required.
The device must be connected to the
protective earth conductor (see
– The device must be capable of being
isolated from the mains, for example by
fuses, with an isolating distance of at least
3 mm.
).