STIEBEL ELTRON DHC-E 20 User manual

8784.01
°C
Power
DHC-E 20, DHC-E 30
English
DHC-E TANKLESS ELECTRIC WATER HEATERS
INSTALLATION INSTRUCTIONS FOR THE LICENSED
PLUMBER AND ELECTRICIAN
248510
English Table of contents
Temperature increase above ambient
water temperature 2
General 6
Mounting the unit 6
Water connections 6
Electrical connections 7
Putting the water heater into operation 7
Normal maintenance 7
Technical Data 7
Troubleshooting 8
Spare parts 8
Warranty 8

– 2 –
English
Español
Maximum temperature increase above ambient water temperature
Aumento máximo de temperatura del aqua fría entrante
Table 1
DHC-E 20 @ 208 V 14.4 1.51 1.82 2.18 2.72 3.63 5.45
@ 220 - 240 V 19.2 2.02 2.42 2.91 3.63 4.84
39 °F 50 °F 59 °F 68 °F 77 °F 86 °F 95 °F 104 °F
DHC-E 30 @ 208 V 21.6 2.27 2.72 3.27 4.09 5.45
@ 220 - 240 V 28.8 3.03 3.63 4.36 5.45
105 °F Warm water outlet temperature
105 °F Temperatura del aqua caliente
Warm water flow rate [ GPM ]
Flujo de aqua caliente [ GPM ]
Cold water inlet temperature
aqua fría temperatura de entrada
Type / Tipo kW
DHC-E 20 @ 208 V 14.4 5.73 6.87 8.25 10.31 13.75 20.62
@ 220 - 240 V 19.2 7.64 9.16 11.00 13.75 18.33
4 °C 10 °C 15 °C 20 °C 25 °C 30 °C 35 °C 40 °C
DHC-E 30 @ 208 V 21.6 8.59 10.31 12.37 15.47 20.62
@ 220 - 240 V 28.8 11.46 13.75 16.50 20.62
40 °C Warm water outlet temperature
40 °C Temperatura del aqua caliente
Warm water flow rate [ l/min ]
Flujo de aqua caliente [ l/min ]
Cold water inlet temperature
aqua fría temperatura de entrada
Type / Tipo kW
DHC-E 20 @ 208 V 14.4 1.33 1.56 1.82 2.18 2.72 3.63 5.45
@ 220 - 240 V 19.2 1.77 2.08 2.42 2.91 3.63 4.84
39 °F 50 °F 59 °F 68 °F 77 °F 86 °F 95 °F 104 °F
DHC-E 30 @ 208 V 21.6 1.99 2.33 2.72 3.27 4.09 5.45
@ 220 - 240 V 28.8 2.66 3.11 3.63 4.36 5.45
113 °F Warm water outlet temperature
113 °F Temperatura del aqua caliente
Warm water flow rate [ GPM ]
Flujo de aqua caliente [ GPM ]
Cold water inlet temperature
aqua fría temperatura de entrada
Type / Tipo kW
DHC-E 20 @ 208 V 14.4 5.03 5.89 6.87 8.25 10.31 13.75 20.62
@ 220 - 240 V 19.2 6.71 7.86 9.16 11.00 13.75 18.33
4 °C 10 °C 15 °C 20 °C 25 °C 30 °C 35 °C 40 °C
DHC-E 30 @ 208 V 21.6 7.54 8.84 10.31 12.37 15.47 20.62
@ 220 - 240 V 28.8 10.06 11.78 13.75 16.50 20.62
45 °C Warm water outlet temperature
45 °C Temperatura del aqua caliente
Warm water flow rate [ l/min ]
Flujo de aqua caliente [ l/min ]
Cold water inlet temperature
aqua fría temperatura de entrada
Type / Tipo kW
DHC-E 20 @ 208 V 14.4 1.14 1.30 1.47 1.70 2.02 2.48 3.20 4.54
@ 220 - 240 V 19.2 1.51 1.73 1.96 2.27 2.69 3.30 4.27 6.05
39 °F 50 °F 59 °F 68 °F 77 °F 86 °F 95 °F 104 °F
DHC-E 30 @ 208 V 21.6 1.70 1.95 2.21 2.55 3.03 3.71 4.81
@ 220 - 240 V 28.8 2.27 2.59 2.94 3.41 4.04 4.95 6.41
125.6 °F Warm water outlet temperature
125.6 °F Temperatura del aqua caliente
Warm water flow rate [ GPM ]
Flujo de aqua caliente [ GPM ]
Cold water inlet temperature
aqua fría temperatura de entrada
Type / Tipo kW
DHC-E 20 @ 208 V 14.4 4.30 4.91 5.57 6.44 7.64 9.37 12.13 17.18
@ 220 - 240 V 19.2 5.73 6.55 7.43 8.59 10.18 12.50 16.17 22.91
4 °C 10 °C 15 °C 20 °C 25 °C 30 °C 35 °C 40 °C
DHC-E 30 @ 208 V 21.6 6.44 7.36 8.36 9.67 11.46 14.06 18.19
@ 220 - 240 V 28.8 8.59 9.82 11.15 12.89 15.27 18.75 24.26
52 °C Warm water outlet temperature
52 °C Temperatura del aqua caliente
Warm water flow rate [ l/min ]
Flujo de aqua caliente [ l/min ]
Cold water inlet temperature
aqua fría temperatura de entrada
Type / Tipo kW

– 3 –
°C
Power
3/4”
NPT
3/4”
NPT
8785.01
8786.01
[ inch (mm) ]
[ pouse (mm) ]
14 4/8(367)
1 5/8(42)
12 2/8(310)
2 (50)
2 4/8(65)
4 (102)
4 5/8(116)21 6/8(552)
DHC-E 20 DHC-E 30
B
A
10
°C
Power
°C
Power
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15 6/8(400)

– 4 –
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Power
°C
Power
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Power
2x2x
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3x3x
b.
a.
a.
8790.01
8789.01
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12 5/8(320)
1 7/8(47) 11 5/8(295)
19 5/8(500)
CKT 1 CKT 2 CKT 3
CKT 1 CKT 2
DHC-E 20 DHC-E 30
14 13
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3 7/8inch (100 mm)
3 7/8pouse (100 mm)
18 4x
D
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[ inch (mm) ]
[ pouse (mm) ]

– 5 –
OFF
ON
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OFF
ON
DHC-E 20 DHC-E 30
8794.01
8792.01 8793.01
G
H
220 - 240 V / 208 V AC
CKT 1 CKT 2
220 - 240 V / 208 V AC
CKT 1 CKT 2 CKT 3
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– 6 –
Legend to figures
1Temperature adjustment knob
2Temperature display
3"Power" light
4Hot water connection
5Cold water connection
6Wiring block
7Electronic control unit
8Safety thermal cut out
9Heating system
10 Knock-outs for wires
11 Water supply line for faucet installation
12 Sink
13 Cold valve (right)
14 Hot valve (left)
15 Screws and plastic wall anchors
General
The DHC-E 20 and DHC-E 30 are designed
to supply hot water for a house or
apartment. Unlike a conventional storage
type water heater the DHC-E tankless water
heater does not store hot water. Instead,
water is heated instantaneously as it flows
through the unit. Due to the absence of
stand-by losses, the DHC-E offers greater
energy efficiency than storage type water
heaters.
The input of heat into the water is controlled
electronically. The DHC-E will deliver any
water temperature between 86 ºF (30 ºC)
and 125 ºF (52 ºC). Please set the desired
temperature using the knob on the front
cover. The LED displays the temperature
that the unit will produce in °C. Please use
the conversion table on the unit in order to
obtain degree Fahrenheit. The maximum
temperature is electronically limited to
125 °F (52 °C).
THIS MANUAL MUST BE READ CAREFULLY BEFORE ATTEMPTING TO INSTALL THE DHC-E
WATER HEATER. IF YOU DO NOT FOLLOW THE SAFETY RULES OR THE INSTRUCTIONS
OUTLINED IN THIS MANUAL, THE UNIT MAY NOT OPERATE PROPERLY AND IT COULD CAUSE
PROPERTY DAMAGE, SERIOUS BODILY INJURY AND/OR DEATH.
STIEBEL ELTRON, INC. WILL NOT BE LIABLE FOR ANY DAMAGES BECAUSE OF FAILURE TO
COMPLY WITH THE INSTALLATION AND OPERATING INSTRUCTIONS OUTLINED IN THIS
MANUAL OR BECAUSE OF IMPROPER USE. IMPROPER USE INCLUDES THE USE OF THIS
APPLIANCE TO HEAT ANY LIQUID OTHER THAN WATER. FAILURE TO COMPLY WITH
THE INSTALLATION AND OPERATING INSTRUCTIONS OR IMPROPER USE VOIDS WARRANTY.
NEVER REMOVE THE UNIT’S COVER UNLESS THE ELECTRICITY IS TURNED OFF.
IF YOU HAVE ANY QUESTIONS REGARDING THE INSTALLATION OR OPERATION OF THIS
WATER HEATER, OR IF YOU NEED AN ADDITIONAL INSTALLATION MANUALS,
PLEASE CALL OUR TECHNICAL SERVICE LINE AT 800-582-8423 (USA AND CANADA ONLY).
IF YOU ARE CALLING FROM OUTSIDE THE U.S. OR CANADA, PLEASE CALL USA 413-538-7850
AND WE WILL REFER YOU TO A QUALIFIED STIEBEL ELTRON SERVICE REPRESENTATIVE IN
YOUR AREA.
In case the “Power” light is flashing while the
unit operates, the water flow rate exceeds
the heating capacity of the unit. Reduce the
hot water flow rate in order to let the unit
achieve the set point temperature.
In case you have questions regarding the way
you plan to use the DHC-E, please call our
technical service line at 800-582-8423 (USA
and Canada). For service outside the U.S.
and Canada, please call us at
USA 413-538-7850. You can also e-mail us
at [email protected] or fax us at
USA 413-538-8555.
One DHC-E can be used for the following
applications.
C1
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Typical residential installation
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Typical commercial installation
Mounting the unit
UNIT MUST BE INSTALLED IN A
VERTICAL POSITION WITH THE
WATER FITTINGS POINTING DOWN-
WARD. DO NOT INSTALL UNIT
WHERE IT WOULD ROUTINELY BE
SPLASHED WITH WATER. ELECTRIC
SHOCK MAY RESULT.
1. Install DHC-E as close as possible to the
main hot water draw-off points.
2. Install DHC-E in a frost free area. If frost
may occur, remove unit before freezing
temperatures set in.
3. Leave a minimum of 5" of clearance on all
sides for servicing.
4. Remove the cover D.
5. Mount unit securely to wall by putting four
screws through mounting holes E .
Screws and plastic wall anchors for
mounting on masonry or wood are
provided.
Water connections
1. All plumbing work must comply with na-
tional and applicable state and local
plumbing codes.
2. A pressure reducing valve must be installed
if the cold water supply pressure exceeds
150 PSI (10 bar).
3. Make certain that the cold water supply
line has been flushed to remove any scale
and dirt.
4. An isolating valve is an integral part of the
cold water inlet. This valve allows the unit
to be isolated for maintenance purposes.
5. The cold water connection (inlet) is on the
right side of the unit, and the hot water
connection (outlet) is on the left side of
the unit.
NOTE: EXCESSIVE HEAT FROM
SOLDERING ON COPPER PIPES
NEAR THE DHC-E MAY CAUSE
DAMAGE.
6. Tankless water heaters such as the DHC-E
are not required to be equipped with a
Pressure and Temperature Relief Valve
(P&T). If the local inspector will not pass
the installation without a P&T, it should be
installed on the hot water outlet side of
the unit.
7. The DHC-E is designed for connection to
copper tubing, PEX tubing or a braided
stainless steel hose with a 3/4“ NPT
female tapered thread. If soldering near
the unit is necessary, please direct the
flame away from the housing of the unit in
order to avoid damage.
8. When all plumbing work is completed,
check for leaks and take corrective action
before proceeding.

– 7 –
English
Electrical connection
WARNING: BEFORE BEGINNING
ANY WORK ON THE ELECTRIC
INSTALLATION, BE SURE THAT MAIN
BREAKER PANEL SWITCHES ARE “OFF“
TO AVOID ANY DANGER OF ELECTRIC
SHOCK. ALL MOUNTING AND
PLUMBING MUST BE COMPLETED
BEFORE PROCEEDING WITH
ELECTRICAL HOOK-UP. WHERE
REQUIRED BY LOCAL, STATE OR
NATIONAL ELECTRICAL CODES THE
CIRCUITS SHOULD BE EQUIPPED WITH
A “GROUND FAULT INTERRUPTER“.
1. All electrical work must comply with natio-
nal and applicable state and local electrical
codes.
2. The DHC-E should be connected to
properly grounded dedicated branch
circuits of proper voltage rating. Ground
must be brought to the “Ground“ at the
circuit breaker panel. The DHC-E 20 and
DHC-E 30 must have multiple power
sources G.
A DHC-E 20 requires two independant
circuits. Use two AGW # 8 supply cables
protected by two seperate double pole
50 Amp. breakers (see 1
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).
A DHC-E 30 requires three independant
circuits. Use three AGW # 8 supply cables
protected by three seperate double pole
50 Amp. breakers.
In both cases, make sure that the unit is
properly grounded (see
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). Please refer
to the technical data table for the correct
wire and circuit breaker size.
3. The wire must be fed through the knock-
outs located between the hot and cold
water connections F . The “live“ wires
must be connected to the slots on the ter-
minal block marked L and L. The ground
wire must be connected to slot marked
with the ground symbol.
4. Reinstall the cover with screws.
WARNING: AS WITH ANY
ELECTRIC APPLIANCE, FAILURE
TO ELECTRICALLY GROUND UNIT MAY
RESULT IN SERIOUS INJURY OR DEATH.
Putting the water heater
into operation
WARNING: OPEN HOT WATER
FAUCET FOR A FEW MINUTES
UNTIL WATER FLOW IS CONTINUOUS
AND ALL AIR IS PURGED FROM WATER
PIPES. THE UNIT’S COVER MUST BE
INSTALLED BEFORE THE CIRCUIT
BREAKERS ARE TURNED ON.
1. Turn on circuit breakers to bring electrical
power to the unit.
2. Adjust the water temperature to the
desired level using the knob on the front
cover of the unit. The DHC-E displays the
temperature in degree Celsius. There is a
conversion table on the front cover that
helps to convert from degree Celsius to
degree Fahrenheit.
3. Turn on hot water and wait twenty
seconds until temperature has stabilized.
4. Check the water temperature with your
hand and make sure that it does not feel
too hot. Reduce if necessary.
5. Explain to the user how the unit works
and familiarise him or her with its use.
Advise the user about possible hazards
(hot water temperature up to 125 °F /
52 °C). Hand over these instructions, to
be kept for future reference.
Normal maintenance
STIEBEL ELTRON DHC-E tankless water
heaters are designed for a very long service
life. Actual life expectancy will vary with
water quality and use. The unit itself does
not require any regular maintenance.
However, to ensure consistent water flow,
it is recommended to periodically remove
scale and dirt that may build up at the
aerator of the faucet or in the shower head.
Also, the DHC-E has a built in filter screen
that should be cleaned from time to time. In
order to do this, turn off the cold water
supply at the isolating valve and remove the
cap of the filter screen H. Clean screen
and put the screen and cap back into their
original position.
OTHER THAN THE FILTER SCREEN,
THE DHC-E DOES NOT
CONTAIN ANY PARTS SERVICEABLE BY
THE LAY PERSON. IN CASE OF
MALFUNCTION PLEASE CONTACT A
LICENSED PLUMBER OR ELECTRICIAN.
Model DHC-E 20 DHC-E 30
Water connections NPT 3/4"
Weight lbs. / kg 21 / 9.5 24.25 / 11
Tested to pressure PSI / bar 300 / 20
Working pressure max. PSI / bar 150 / 10
Nominal water volume GAL / l 0.26 / 1.0 0.39 / 1.5
Min. water flow
to activate unit
GPM / l/min 0.58 / 2.2 0.87 / 3.3
Pressure loss in unit PSI / bar 1.45 / 0.1 1.45 / 0.1
R equired wire size
AWG COPPER 8 8 8 8
Min. required circuit breaker size A 2 x 40 2 x 50 3 x 40 3 x 50
Max. amp. load A 70 80 105 120
Wattage kW 14.4 19.2 21.6 28.8
Voltage V 208 220 - 240 208 220 - 240
Phase 11
– Suitable for supply with water up to 107.6 °F / 42 °C
– Tankless water heaters are considered a non-continuous load
– Conductors should be sized to maintain a voltage drop of less than 3 % under load
Technical Data

CAP 248510 / 33226 / 1 / 7771 · Mü · These instructions are subject to alteration notice! · Estas instrucciones están sujetas a correcciones!
WARRANTY
RESIDENTIAL & COMMERCIAL WARRANTY: STIEBEL ELTRON WARRANTS TO THE ORIGINAL OWNER THAT THE
DHC-ETANKLESS ELECTRICWATER HEATER WILL BE FREE FROM DEFECTS INWORKMANSHIP AND MATERIALS FOR
A PERIOD OF THREE YEARS FROMTHE DATE OF PURCHASE. SHOULDTHE PART(S) PROVETO BE DEFECTIVE UNDER
NORMAL USE DURING THIS PERIOD, STIEBEL ELTRON, INC. WILL BE RESPONSIBLE FOR REPLACEMENT OF THE
DETECTIVE PART(S) ONLY. STIEBEL ELTRON, INC. IS NOT RESPONSIBLE FOR LABOR CHARGESTO REMOVEAND/OR
REPLACE THE DEFECTIVE PART(S), OR ANY INCIDENTIAL OR CONSEQUENTIAL EXPENSES.
SHOULDTHE OWNERWISHTO RETURNTHETANKLESS ELECTRICWATER HEATER FOR REPAIR, THE OWNER MUST
FIRST SECURE WRITTEN AUTHORIZATION FROM STIEBEL ELTRON, INC. THE OWNER SHALL BE REQUIRED TO
SHOW PROOF OF PURCHASE DATE, AND TO PAY ALL TRANSPORTATION COSTS TO RETURN THE DEFECTIVE
PART(S) OR TANKLESS ELECTRIC WATER HEATER FOR REPAIR OR REPLACEMENT. WARRANTY IS VOID IF WATER
HEATER HAS BEEN INSTALLED OR USED IMPROPERLY OR IF DESIGN HAS BEEN ALTERED IN ANY WAY.
STIEBEL ELTRON, INC.
242 Suffolk Street
Holyoke MA 01040
PHONE: [phone] or 413-538-7850
FAX: [phone]
E-Mail [email protected]
www.stiebel-eltron-usa.com
STIEBEL ELTRON, INC.
242 Suffolk Street
Holyoke MA 01040
PHONE: [phone] or 413-538-7850
FAX: [phone]
E-Mail [email protected]
www.stiebel-eltron-usa.com
1 Heating system 24 91 58
2 Electronic control device: Master 24 93 18
3 Electronic control device: Slave 24 93 19
4 Safety thermal cut out 17 03 05
5 Flow sensor 24 91 59
6 Cold water connection 24 91 67
7 Warm water connection 24 91 68
8 Temperature adjustment knob 16 35 73
Troubleshooting
If you are not able to resolve a problem please contact us toll free at 800-582-8423 before removing the unit from the wall.
STIEBEL ELTRON is happy to provide technical assistance. In most instances, we can resolve the problem over the phone.
Symptom Possible Cause Solution
No hot water
Water not hot enough
LED displays one of the following fault codes:
91, 92, 93, 94, 95, 96, 97
– circuit breakers off
– safety thermal cut-out tripped
– not enough flow rate to activate unit
– water flow rate too high
– voltage too low
– problem with electronic control module
– turn circuit breakers on
– reset thermal cut-out
– clean filter screen at unit
– clean faucet aerator or shower head
– reduce water flow rate until light on front
cover stops blinking
– supply correct voltage to unit
– contact STIEBEL ELTRON.
Spare parts H
No. Spare part Model DHC-E 20 DHC-E 30