Installation Instructions; Brief Description; For Contractors; Instructions And Regulations - STIEBEL ELTRON DHB-E 18 Si Gebrauchs- Und Montageanweisung

2. Installation instructions

Key to figures A - G
1 Temperature selector
2 Equipment cap
3 Base, back wall
4 DHW compression fitting
5 Cold water compression fitting
(three-way shut-off valve)
6 Cable grommet (electrical supply cable
from below)
7 Mains terminal
8 Top, back wall
9 Electronics
10 LED diagnostic "traffic light" for operating
and fault indications
11 Socket for set value transducer cable
12 Safety pressure limiter (AP 3) with reset
button
13 Fixing toggle
14 Heating system
15 Flow sensor
16 Set value transducer cable plug
17 High limit safety cut-out (STB)
18
Unit rating plate
19 Mounting bracket
20 Strainer
21 Flow limiter
22 Washer

2.1 Brief description

The electronically controlled instantaneous
water heater DHB-E ... Si electronic is a
pressure device to DIN 1988 for the heating
of cold water, and to supply one or more
draw-off points.
The bare wire heating system is suitable for
water with low limescale or with limescale
content (see "5.2 Application ranges").
2.2 Important information
Air trapped in the cold water supply
can damage the bare wire heating sys-
tem inside the equipment, or trip the safety
system.
If the water supply to the DHB-E ... Si
electronic is interrupted
- e.g. because of a risk of frost or due to
work on the water mains, take the fol-
lowing precautions before bringing the
equipment back into use:
1. Remove fuses or trip the MCBs.
2. Open and close a draw-off valve
downstream of the equipment several
times until all air has been purged from
the cold water supply line and the equip-
ment.
3. Replace the fuses or reset the MCBs.
The DHB-E ... Si electronic is equip-
ped with an air detector which, to
a great extent, prevents damage to
the heating system:
If, during operation, air is drawn into the
DHB-E ... Si electronic, the equipment
shuts down the power for a few seconds,
thereby protecting the heating system.

for contractors

Valves:
• Stiebel Eltron pressure valves for instan-
taneous water heaters, for installation on
finished walls (see "8. Special accesso-
ries")
• Installation may be carried out using com-
mercially available pressure valves.
• Thermostatic pressure valves (see note
"1.6 Recommended adjustment").
• All information in these operating and
installation instructions must be followed
carefully. They contain important details
regarding safety, operation, installation and
maintenance of the equipment.
2.3 Instructions and regula-
tions
• The installation (water and electrical
work) and commissioning, as well as the
maintenance of this equipment, must only
be carried out by a qualified contractor in
accordance with these instructions.
• Perfect function and safe operation can
only be guaranteed when using original
accessories and spare parts intended for
this equipment.
• Observe all locally applicable instructions
and regulations regarding water and
electrical connections, such as DIN 1988,
DIN 4109, DIN 44851 etc.
• Observe all local water and electricity
supply company regulations.
• Install the lower area of the equipment
flush with the wall (observe dimension
≥ 110 mm B ).
• The type plate (open the hinged flap on
the equipment cap).
• See also "5. Specification".
The specific electrical resistance of
the water may not be below the value
written on the rating plate.
If the water is coming from a water-net-
work the lowest value of the water resist-
ance must be considered, (see „5.2 area of
application").
The specific electrical resistance of the
water is generally known by the water pro-
vider.
• Install the equipment only in an enc-
losed, frost-free room. Store dismantled
equipment in frost-free conditions, since
there is always a little water left inside the
equipment.
• The protection level IP 25 (hose-proof)
is only guaranteed if a correctly installed
cable grommet is used.
• Water installation:
– Cold water pipe material:
Steel, copper or plastic pipe systems.
– DHW pipe material:
Copper or plastic pipe systems*
Operating temperatures up to a max.
60 °C can be reached with the
DHB-E...Si instantaneous water heater.
Maximum loads of 95 °C / 1.0 MPa may
occur briefly in the installation in the
event of a fault. The plastic pipe system
used must be designed for such condi-
tions.
• A safety valve is not required.
• Never operate with pre-heated water.
• Never use valves for open systems.
• For thermostatic valves, see
"1.6 Recommended adjustment".
• Electrical installation:
• Electrical connection only to permanently
wired mains power cables
• The equipment must be able to be dis-
connected from the mains power supply,
for example by fuses that disconnect all
poles with at least 3 mm contact separati-
on.
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