Idiomas disponibles
Idiomas disponibles
2. Installation instructions
2.1 Unit structure
1 Thermostat
2 Cover
3 Rear wall - lower part
4 Hot water connection
5 Cold water connection (3-way isolating
valve)
6 Rear wall - upper part
7 Terminal block
8 Securing screw - module carrier (service)
9 Safety switch with reset button (blue)
10 Heating system
11 Insertion point for thermostat fly-lead
plug
12 Securing screw for unit
13 Plug for thermostat fly-lead
14 Unit securing arrangement - bottom
15 Electrical lead, concealed in the lower
part of the unit
16 Dimension for "wall flush fitting"
installation
17 Electrical lead, concealed, in upper part of
unit
18 Unit securing arrangement at top, for
new installation
19 Knock-out point for installation bracket
provided for HDE 18-27 electronic and
for installing HDE electronic installation
bracket if the unit is replaced
20 Knock-out point for installation bracket
of Stiebel Eltron HDE electronic
21 Unit securing arrangement in the event
of replacement against Stiebel Eltron
appliance
22 Knurled knob for rear wall alignment in
the event of tiles being offset
23 Dowel holes in the event of replacement
of third-party devices
24 Temperature limitation screw
25 Blanks G ½ (Option)
26 Cable grommet
12
for the qulified installer
2.2 Important notes
Air in the cold water pipe may de-
stroy the bare wire heating system of
the unit, or cause the safety system to actu-
ate.
If the water feed to the HDE elec-
tronic has been interrupted, for exam-
ple due to the risk of freezing, work on the
water mains, etc., the following procedures
must be followed before the system is taken
back into operation:
1. Remove the fuses or disconnect them.
2. Turn any hot water fittings downstream
of the unit fully on until the unit and the
cold water pipe have been bled and are
free of air.
3. Replace the fuses again, or connect them
again.
The HDE electronic unit is fitted
with an air detection device, which
will largely prevent damage to the
heating system:
If air is introduced into the HDE elec-
tronic during operation, the unit will
switch the power off for a few seconds,
and so protect the heating system.
Note: This function can also be activated
if the fitting is turned on again immedi-
ately after it has been turned off.
All the information provided in these
Instructions for Installation and Use must
be followed carefully. They provide im-
portant details regarding safety, opera-
tion, installation, and maintenance of the
unit.
2.3 Brief description
The HDE electronic electronically controlled
instantaneous water heater is a pressurised
unit for the heating of cold water in accordance
with DIN 1988, with which one or more
water taps can be supplied.
If the preselected output temperature is not
achieved with the tap fully turned on, this
means that more water is flowing through the
unit than the heating elements can heat (out-
put limit 18, 21, 24, or 27 kW). In this event,
the water volume needs to be reduced ac-
cordingly at the hot water outlet.
The bare wire heating system is enclosed with
a pressure-resistant copper jacket. The heating
system is especially well-suited for water with
high limescale risk (for areas of use see Table 3).
2.4 Special fittings
For Stiebel Eltron two-handle pressure fittings
for instantaneous water heaters, see "2.15
Special Accessories".
Installation with conventional commercial
fittings is also possible.
For thermostatic fittings, see Instructions "1.7
Setting recommendations".
2.5 Regulations and provisions
– Installation (water and electrical installation)
and first start-up and maintenance of this
unit may only be carried out by a qualified
installer, in accordance with these Instruc-
tions.
– Trouble-free function and operational reli-
ability and safety can only be guaranteed if
the original accessories and spare parts
intended for the unit are used.
– Regulations of the local energy supply com-
pany.
– Regulations of the water supply company
concerned
– Install the device flush-fitted to the wall in
the lower part (respect the dimension
110 mm (16)).
Also secure the unit at the bottom (14).
The following details are also to be
respected:
– The unit rating plate
– Technical data.
The specific electrical resistance of
the water must not be less than that
indicated on the rating plate. Where a pub-
lic water supply network is involved, the
lowest electrical resistance of the water is
to be taken into account (see Table 4).
Consult your water supply company for the
specific electrical resistance or electrical
conductivity of the water.
– Operation with pre-heated water at more
than 60 °C is not permissible.
– Materials for the water installation:
Cold water pipe:
Steel, copper, or plastic pipes
– Operating conditions as per DIN 1988,
Part 2, December 1988, Section 2.2.3,
Table 1.
Hot water pipe:
Copper
Plastic pipe systems with DVGW testing
mark
Under normal operating conditions, and in
the event of a fault, the operating conditions
in accordance with DIN 1988, Part 2, De-
cember 1988, Section 2.2.3, Table 1.
– Electrical connection only to permanently-
installed wires.
– Fittings for open-outlet units are not per-
mitted.
– For thermostat fittings, see "2.1.5 Special
Accessories".
– No safety valve is required.
– The unit must be capable of isolation from
the mains, for example by means of fuses,
with an isolating distance of at least 3 mm
to all poles.
