Installation Instructions; Structure; Special Fittings; Important Instructions - STIEBEL ELTRON DHB 12 Si Gebrauchs- Und Montageanweisung

2. Installation instructions

Structure

D J
and
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 Cable grommet
10 Upper part of the back plate
11 Terminal block
12 Safety pressure limiter (AD 3)
12 a Reset button for safety pressure limiter
(in the event of a fault)
13 Differential pressure switch/flow
regulator MRS
14 Heating system
15 Fastening screw
16 System pressure switch
17 Toothed bar
18 Setting lever
19 Lower part of device fixing assembly
20 Electricity supply concealed in lower
area of device
21 Electricity supply concealed in upper
area of device
22 Device fixing point for replacement
against DHA
23 Device fixing point on top in new
installation
24 Dimension for installation, "wall flush
fitting"
25 Fixing holes for replacing third-party
products
26 Knurled nut for rear wall alignment in
the event of tiles being uneven
27 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
28 Knock-out point for installed fitting
bracket of Stiebel Eltron DHE
Fittings
# Fittings for open units are not permitted!
# In case of low water pressure hand-held
showers with low pressure loss must be
fitted see "Special fittings" page 14.
# Stiebel Eltron twin-handle fittings for
instantaneous water heater see "Special
fittings" page 14.
# One-hand mixer and thermostatic fittings
must be suitable for hydraulically
controlled instantaneous water heaters.
# Practical hints:
So that the switch-on quantities (see Ta-
ble 2) of stage I and II are safely reached,
the pressure loses of the instantaneous
water heater, fitting, hand-held shower,
shower hose and the pipe network must
be taken into account upon installation.
Typical pressure loss values for a shower
water quantity of approx. 10 l/min:
– one-hand mixer . . . . . 0.04 - 0.08 MPa
– thermostatic fittings . . 0.03 - 0.05 MPa
– hand-held shower . . . . 0.03 - 0.15 MPa
12
for the qualified installer
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 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 (24)). Also secure the device at
the bottom (19).
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.
Water Connection
#
– Materials suitable for cold water
connection
Steel, Copper or Plastic pipe system
– Materials suitable for hot water
connection
Copper or Plastic
Installation with an approved plastic
piping system is possible.
– A safety valve is not required.
– Operation with pre-heated water of
more than 25 °C is not permitted.
– Accompanying pipe heating (trace
heating) is not permitted.
– Fittings for open devices are not
permitted.
# Electrical Connection
– Electrical connection only to a permanent
connection.
– The device must be capable of being
isolated from the mains, for example by
fuses, with an isolating distance of at least
3 mm.
The device must be connected to the
protective earth conductor.