STIEBEL ELTRON DHC 6 User manual

DHC 3, DHC 4, DHC 6, DHC 8
Unvented small instantaneous water heaters
Operation and installation instructions
Operating Instructions 13
Description of the unit 13
Key facts in brief 13
Installation instructions 14 - 20
Technical data, brief description, 15
installation location, regulations and
provisions
Preparing to install the unit 16
Installing the unit
First start-up 20
Servicing instructions 20
Trouble-shooting 21
Guarantee 21
Installation template 39 - 40
Fig. 1
This water heater must be installed (water and electrical installation), commissioned and serviced by approved
service technicians in accordance with these instructions.

13
Type Power* 2 l/min 4 l/min 6 l/min 8 l/min 10 l/min
7044.01
Fig. 2
* 230 V Volt supply
Table 1
Operating Instructions
(for the user and the qualified installer)
Legend to Figure 2
1 “Power“ light êÿ Unit is heating up
2 “Overheating“ light êÿ Unit is
overheating
Description of the unit
The DHC hydraulically-controlled
instantaneous water heater heats the water
while it is flowing through the unit. The
heating power is switched on automatically
in the event of the minimum flow rate
being exceeded. The “Power” light (Fig. 2,
Item 1) indicates that the heating system is
switched on.
Key facts in brief
The DHC is equipped with an overheating
protection system. In the event of
overheating, the heating power will be
switched off, and the “Overheating” light
(Fig. 2, Item 2) will come on. After a
cooling-off phase, the unit will automatically
switch the heating power back on, and the
“Overheating” light will go out. If the unit
is overheating, this indicates that the
incoming water volume is too small
êêêÿ Open the fitting wider.
The outlet temperature can be reduced by
increasing the flow rate or by mixing in cold
water. The hot water output depends on
the capacity of the unit, the cold water
temperature, and the flow rate.
Table 1 shows the temperature rise of
particular units as a function of the flow
rate. If these volumes are added to the cold
water temperatures which prevail at the
installation location, the particular hot water
temperature in each case can be obtained.
Care
A damp cloth is all that is needed to look
after the housing of the unit. Do not use
any effervescent cleaning agents or agents
with a potentially solvent effect.
Maintenance
Maintenance work may only be
carried out by a qualified installer.
Page 21 provides a summary of faults
which you can deal with yourself.
21
Temperature increase
DHC 8 8,8 kW _ 32 °C 21 °C 16 °C 13 °C
DHC 3 3,0 kW 22 °C 11 °C 7 °C 5 °C 4 °C
DHC 3 U 3,5 kW 25 °C 13 °C 8 °C 6 °C 5 °C
DHC 4 4,4 kW 32 °C 16 °C 11 °C 8 °C 6 °C
DHC 6 6,6 kW _ 24 °C 16 °C 12 °C 10 °C
DHC 6 S
DHC 6 U 6,6 kW _ 24 °C 16 °C 12 °C 10 °C

14
Fig. 3
7046.01
DHC 3, DHC 4, DHC 6, DHC 6 S, DHC 8
17
18
19
20
21
22
23
24
25
26
27
29
Installation
instructions
(for the qualified installer)
Composition of the unit (Fig. 3)
Under-sink installation
DHC 3 U, DHC 6 U, DHC 6 S
1Hot water connection G 3/8 *
2Cold water connection G 3/8 *
3Thermostat
4Overheating light
5Power light
6Safety thermal cut-out with reset
button
7Differential pressure switch
8Flow rate adjustment screw
9Terminal strip
10 Rear wall
11 Strain relief unit (only DHC 3 U)
12 Connection cable with plug, 800 mm
long (only DHC 3 U, enclosed)
13 Jet regulator for fitting (only DHC 3 U,
enclosed)
14 Cover
15 Function diaphragm
16 Heating system
* The connection pipe for the DHC 6 S
must be connected during installation.
Over-sink installation
DHC 3, DHC 4, DHC 6, DHC 6 S,
DHC 8
17 Terminal strip
18 Overheating light
19 Power light
20 Safety thermal cut-out with reset
button
21 Differential pressure switch
22 Flow rate adjustment screw
23 Rear wall
24 Cold water connection G 1/2, can be
used for surface installation and
concealed installation
25 Hot water connection G 1/2, can be
used for surface installation and
concealed installation
26 Cover
27 Function diaphragm
28 Heating system
29 Thermostat
Important note
All the information in these
Installation and Operating
Instructions must be followed carefully.
These Instructions provide important
details regarding safety, operation,
installation, and maintenance of the unit.
24
25
28
DHC 3 U, DHC 6 U, DHC 6 S
7045.02
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16

15
Fig. 4
7052.02
Technical data
DHC 3 U DHC 3, DHC 4, DHC 6, DHC 6 S, DHC 8
DHC 6 U
DHC 6 S
7051.01
Brief description
The Stiebel Eltron DHC instantaneous
water heater is a hydraulically-controlled
pressure unit for heating cold water, with
which one or more water taps can be
supplied; see Table 2.
Installation location
The unit is suitable for the
preparation of hot water (potable
water supply), and is to be installed as far
as possible in unvented areas free of the
risk of freezing, as close as possible to
the water tap (dismantled units are to be
stored so as to be free of any risk of
freezing, since there will always be
residual water left in the unit).
The DHC unit is to be installed
vertically, in accordance with Fig. 4.
Under-sink installation:
DHC 3 U, DHC 6 U, and DHC 6 S.
Over-sink installation:
DHC 3, DHC 4, DHC 6, DHC 6 S and
DHC 8.
Regulations and provisions
– Regulations issued by local energy supply
companies.
– Regulations issued by the water supply
companies concerned.
Other data to be taken into
account:
– Currently-applicable data on the unit
rating plate.
– Technical data.
– Install the unit flush with the wall.
– Piped supplementary heating is not
permissible.
– Water installation material:
Cold water pipe:
Steel or copper
Hot water pipe:
Copper.
– Electrical connection to permanently-
installed leads (except for DHC 3 U with
connection lead).
– The unit must be capable of being
isolated from the mains supply, e.g. by
fuses, with a minimum isolation path of
3 mm.
The unit must be connected to the
safety earth terminal (see Fig. 14).
– Fittings for open units are not permitted.
– Safety valves are not required.
1) External thread
2) DHC 6 S by under-sink installation G 3/8
lSuitable
Table 2
Type DHC 3 U DHC 6 U DHC 3 DHC 4 DHC 6 DHC 8
DHC 6 S
Design Unvented
Weight kg 2,1 2,5 2,0 2,1 2,4 2,4
Protection class as per VDE 1
Rated overpressure bar 10
Capacity l 0,5
Protection mode as per VDE IP 24
Test mark See unit rating plate
Water connection 1) G 3/8 G 3/8 G 1/2 G 1/2 G 1/2 2) G 1/2
Electrical connection 1/N/PE ~ 220 . . . 240 V
Rated power 220 V kW 3,2 6,0 2,7 4,0 6,0 8,0
at 230 V kW 3,5 6,6 3,0 4,4 6,6 8,8
Over-sink installation for --llll
supplying one or two
draw-off points
Switch-on volumes l/min 1,6 2,6 1,6 1,6 2,6 3,0
240 V kW 3,8 7,2 3,3 4,8 7,2 9,6
Under-sink installation for ll--l-
supplying one draw-off point
Switch-on flow pressure
Pressure loss bar 0,25 0,3 0,25 0,25 0,25 0,3
Suitable for cold water l/min > 1,6 > 2,6 > 1,6 > 1,6 > 2,6 > 3,0
Suitable for cold water
up to °C 25 25 30 20 30 25

16
264 mm
7047.02
12
34
6
7
8
99
100 mm
100 mm G 1/2
104 mm
G 1/2
G 3/8
50 mm
9 mm 280 mm59 mm
270 mm
360 mm
11
10
5200 mm 35 mm
12 mm 65 mm
Legend to Fig. 5
Connection dimensions in mm.
1Hot water connection DHC 3 U,
DHC 6 U, DHC 6 S
2Cold water connection DHC 3 U,
DHC 6 U, DHC 6 S
3Hot water connection, DHC,
concealed
4Cold water connection, DHC,
concealed
5Hot water connection, DHC, above
work surface
6Cold water connection, DHC,
above work surface
7Electrical connection DHC 3 U,
with connection cable and mains
plug enclosed with the unit
DHC 6 U connection cable to be
provided by client.
8Electrical connection concealed
(DHC)
9Electrical connection above work
surface (DHC)
10, 11 Securing holes
Fig. 5
Fig. 7
7049.01
Fig. 6
Legend to Fig. 6
13-17 Marked connection apertures in unit
rear wall
13 Electrical connection, top
14 Electrical connection, bottom
(aperture for Item 20 also)
15 Water connection, concealed
16 Water connection, above work
surface
17 Water connection DHC 6 S
Preparing to install the unit
– Release securing screw (Item 17).
– Remove unit cover (Item 18).
– DHC 3, DHC 4, DHC 6, DHC 8
– Break through cable conduits
Installation from above: Item 13
Installation from below: Item 14
– Break apertures for water
connections:
Concealed Item 15
Exposed Item 16.
– DHC 6 S - under-sink installation
– Break through cable conduits
Installation from above: Item 13
Installation from below: Item 14
– Break apertures for water
connections Item 15 and 17.
7048.01
20 18
7050.01
13
14
15 15
16
16
19
17

17
7057.02 7056.02
Æ4 x 35 mm
Æ4,3 mm
Installing the unit
1. Flush the cold water feed pipe
thoroughly.
2. Install water connection components in
accordance with Figs. 12 and 13
respectively.
3. Cut electrical connection lead to length
as per Fig. 16, and strip off the insulation
(not required for DHC 3 U).
4. Determine the position of the drillholes
with the aid of the installation template
(pages 39 and 40). Press the dowels in
and insert the screws (check the depth
to which the screws are inserted; see
Fig. 8).
Note: When replacing an old DHC unit
(old screw holes can be used), do not
screw in the upper screw until after the
new unit has been fitted ( ).
5. For concealed connections, screw the
water connection into the wall
diaphragm in accordance with Fig. 12.
Guide the unit over the screws and push
downwards ( ).
Straighten the unit and tighten the
screws.
Fig. 9
Fig. 8
min. 4,5 mm
max. 5,5 mm
7055.02
6 mm
Æ4 x 35 mm
Æ6 mm
Æ4 x 35 mm
Æ6 mm

18
Water connection
Under-sink installation
DHC 3 U, DHC 6 U, DHC 6 S
An example of installation with
conventional pressure fitting (Fig. 10).
Items to be provided by client:
1Blender fitting for sink
2Copper pipe Æ10 mm
3Angle valve
4T-piece
– Establish water connection (use
compression fittings provided, Item 5).
– Connect jet regulator unit, Item 6(only
DHC 3 U, enclosed) to the fitting outlet.
Fig. 12
Fig. 11
7053.01
WW KW
7052.02
min. 46
max. 50
mm
Fig. 10
7051.01
7066.02
16
24
3
G 3/8
Fig. 13
Exposed connection (Fig. 12)
– Screw the unit connection nipple
(Item 11) to the water installation (cold
water and hot water; pay attention to
position and installation depth).
– With the connection apertures broken
through, guide the unit over the
connection nipples on the installation
wall.
– Screw the union nut (Item 12) of the
pipe bend (cold water and hot water)
with the gasket (Item 13) onto the
connection nipple.
Connection above work surface
(Fig. 13)
– Guide the connection nipple (Item 14)
through the break-through points on the
rear wall of the unit, and screw the
union nut onto it with the gasket
(Item 15) at the pipe bend (Item 16).
– Connect surface-mounted installation
(Item 17).
Pos. 18 - 20 only with DHC 6 S:
– The washer (20) must be fitted on both
the hot and cold water connection pipe.
11
13
12
5
8
8
7
9
99
10
9
10
Over-sink installation
DHC 3, DHC 4, DHC 6,
DHC 6 S, DHC 8
Examples of installations with
conventional pressure fitting (Fig. 11).
Items to be provided by client:
7Blender fitting for shower
8Blender fitting for sink
9Copper pipe
10 T-piece
7865.01
WW KW
16
15
14
17
DHC 3,
DHC 4,
DHC 6,
DHC 6 S,
DHC 8
WW
KW 18
19
20
DHC 6 S
DHC 3, DHC 4, DHC 6, DHC 6 S, DHC 8
DHC 3, DHC 4, DHC 6,
DHC 6 S, DHC 8
DHC 3 U, DHC 6 U, DHC 6 S

19
Electrical connection
Legend to Fig. 14
1Heating element
2“Overheating” monitor light
3“Power” monitor light
4Safety thermal cut-out
5Differential pressure switch
6Thermostat
To provide protection against the
penetration of water, the cable
seal (Fig. 16, Item 8, or Fig. 17, Item 14)
must be used. Cut out the sealing
diaphragm to fit the electric cable.
DHC 3 U (Fig. 16)
– Pass the connection cable provided
(Item 7) through the cable seal (Item 8)
and the strain relief collar (Item 9).
– Establish the electrical connection
(Item 10) in accordance with Fig. 14,
and tighten the screws of the strain relief
collar.
A protective earth contact socket is
required to connect the unit. After
concluding the installation (see page 20),
insert the mains plug.
DHC 6 U (Fig. 16):
– Push in the cable seal (Item 8)
– Establish the fixed-position lead (Item 7)
for the electrical connection (Item 10) in
accordance with Fig. 14
See page 20 for concluding the installation.
DHC 3, DHC 4, DHC 6, DHC 6 S,
DHC 8:
– For concealed installation, the
connection lead must project with
insulation at least 65 mm out of the wall
(Fig. 15).
·Connection in the upper part of the
unit/surface installation or concealed
installation (Fig. 17).
– Slide in the cable seal (Item 14)
– Lay the fixed-location lead (Item 15) for
the electrical connection (Item 16) in
accordance with Fig. 14.
See page 20 for concluding the installation.
Alternative:
·Connection in the lower part of the
unit/surface installation
In the conditions as supplied, the unit is
prepared for electrical connection in the
upper part of the unit (terminal strip
upwards).
– Press the locking device of the terminal
strip (Item 12) downwards, draw the
strip out, and push it into the lower area
(Item 13).
Guide the connection leads sideways
between the differential pressure
switch and the rear wall.
– Slide in the cable seal (Item 8)
– Lay the fixed-location lead (Item 7) for
the electrical connection (Item 10) in
accordance with Fig. 14.
See page 20 for concluding the installation.
Fig. 16
7061.01 7059.01
Fig. 15
Fig. 14
7060.01
1/N/PE ~
220 ... 240 V
7058.01
Fig. 17
14
15
16
7
13
8
10
9 DHC ... U
DHC 3
DHC 3 U
DHC 4
DHC 6
DHC 6 U
DHC 6 S
DHC 8
1
2
3
4
5
6
1
2
3
4
5
6
115 mm
³65 mm
1/N/PE ~
220 ... 240 V
11
12

20
7062.01
-
°C
+
°C
Concluding the installation
(Fig. 19)
Fit the cover, and secure it with the centre
screw (Item 1).
With DHC 3 U, DHC 6 U and DHC 6 S,
the cover can also be secured as an
alternative with the hexagonal-headed
screws provided (Item 2), in the event of
only a small gap pertaining between the
unit and the floor. To do this, the marked
parts of the cover (Item 3) are to be
broken through.
First start-up
(may only be carried out by a qualified
installer)
Before screwing in/switching on
the fuses, all the hot water valves
connected are to be opened sufficiently
for the pipe network and the unit to be
rendered free of air.
– Check that the small instantaneous water
heater is functioning properly.
Adjusting the flow rate (Fig. 18)
In the event of the desired temperature not
being attained, the flow rate can be limited
by means of the adjustment screw (take
note of the data in Table 1). The flow rate
should be adjusted such that the desired
temperature 35 – 40 °C is reached.
Handover of the unit
Explain to the user how the unit works, and
familiarise them with its operation.
– Advise the user about possible hazards
(danger of scalding).
– Hand over these instructions to be kept
in a safe place.
Servicing instructions
Applicable to all maintenance work
disconnect unit from the mains circuit.
– Clean the filter, Fig. 20
Release the earthing screw (Item 4,
approx. 2 turns), unscrew the cold water
connection pipe from the differential
pressure switch (Item 5) turn 90 °, and
remove it downwards. Clean the filter
(Item 6). Assemble in reverse order.
Ensure that the earthing screw
(Item 4) is properly tightened.
– Activate the safety thermal cut-out,
Fig. 21
Once tripped, the safety thermal cut-out
can be reactivated after the fault has
been rectified by means of the reset
button (Item 7). The current to the unit
must be disconnected.
Fig. 19
Fig. 18
7063.01
6
7
Fig. 21
Fig. 20
7064.017065.01
3
2
1
3
2
4
5

21
Elimination of faults by the user
Fault Cause Rectification
Elimination of faults by the qualified installer
Fault Cause Rectification
No hot water despite the hot water fitting
being fully opened.
The water flow rate required for the system
to switch on has not been achieved (see
Table 2).
– Cleaning or descaling of the flow
regulator in the fitting or in the shower
head.
The differential pressure switch is not
switching the heating on despite the hot
water fitting being fully open.
The water flow rate required for the system
to switch on has not been achieved (see
Table 2).
– Clean the filter (Fig. 20, Item 6) after
shutting off the cold water cable entry.
Despite the appropriate sound being
audible from the differential pressure
switch as if it were switched on, no hot
water is flowing.
– The safety thermal cut-out has switched
the unit off for safety reasons.
– Eliminate the cause of the fault. Press
the reset button on the safety thermal
cut-out (Fig. 21, Item 7). The current to
the unit must be disconnected.
– Dirt contamination or limescale
formation in the flow regulator in the
fitting or in the shower head.
– Filter in differential pressure switch is
blocked.
– Flow rate too small. – Correct the flow rate setting (Fig. 18).
Table 3
Table 4
Overheating light is showing. – Flow rate too small. – Correct the flow rate setting (see Fig. 18
and Table 1).
– Heating element clogged with limescale
(caused by heat thermal cut-out build-up).
– Replace heating element
– Heating element defective. – Replace heating element
Guarantee
For guarantees please refer to the
respective terms and conditions of supply
for your country.
The installation, electrical connec-
tion and first operation of this
appliance should be carried out by a
qualified installer.
The company does not accept liability
for failure of any goods supplied which
have not been installed and operated in
accordance with the manufacturer's
instructions.
Environment and
recycling
Please help us to protect the environment
by disposing of the packaging in
accordance with the national regulations
for waste processing.