STIEBEL ELTRON MINI 2-1 Instruction Manual

Operation and Installation
Funcionamiento e Instalación
Mode D’emploi et Installation
Tankless Electric Water Heater with Electromechanical Flow Switch
Calentador Eléctrico de Agua Sin Tanque con Sensor Electromecánico de Flujo
Chauffe-Eau Électrique Sans Réservoir avec Contacteur Debitmetrique Électromécanique
»Mini
™2-1
»Mini
™2.5-1
»Mini
™3-1
»Mini
™3.5-1
»Mini
™4-2
»Mini
™6-2
Conforms to ANSI/UL Std. 499
Certified to CAN/CSA Std. E335-1 & E335-2-35
Conforme a ANSI/UL Std. 499
Certificación con CAN/CSA Std. E335-1 & E335-2-35
Conforme à la norme ANSI/UL Std. 499
Certifié à la norme CAN/CSA Std. E335-1 & E335-2-35
Tested and certified by WQA to NSF/ANSI372
for lead free compliance.
Probado y certificado por WQA NSF/ANSI 372 para
el cumplimiento de las regulaciones sin plomo.
Testé et certifié par WQA à la NSF/ANSI 372 pour une
utilisation sans plomb.

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GENERAL INFORMATION
1. General Information
Read this entire manual. Failure to follow all the guides, instructions
and rules could cause personal injury or property damage.
Improper installation, adjustment, alteration, service and use of
this unit can result in serious injury.
This unit must be installed by a licensed electrician and plumber. The
installation must comply with all national, state and local plumbing
and electric codes. Proper installation is the responsibility of the
installer. Failure to comply with the installation and operating
instructions or improper use voids the warranty.
Save these instructions for future reference. Installer should leave
these instructions with the consumer.
If you have any questions regarding the installation, use or operation
of this water heater, or if you need any additional installation
manuals, please call our technical service line at 800.582.8423
(USA and Canada only). If you are calling from outside the USA or
Canada, please call USA 413.247.3380 and we will refer you to a
qualified Stiebel Eltron service representative in your area.
1. General Information __________________________________________ 2
1.1 Symbol key___________________________________________________________ 3
2. Safety precautions____________________________________________ 4
3. Register your product ________________________________________ 5
4. Temperature increase above ambient water temperature 6
5. Technical drawings ___________________________________________ 7
6. Overview _____________________________________________________10
6.1 General Description _______________________________________________10
6.2 Important information before supplying power to unit____11
6.3 Hot water output using required aerators____________________12
6.4 Incorrect use________________________________________________________12
6.5 First steps to be taken in the event of malfunction _________12
6.6 Maintenance and care ____________________________________________13
7. Installation instructions _____________________________________13
7.1 Mounting the unit _________________________________________________13
7.2 Plumbing connections ____________________________________________14
7.3 Electrical connection______________________________________________15
8. Initial start-up _______________________________________________16
9. Water heater hand over _____________________________________16
10. Normal maintenance ________________________________________16
11. Technical data________________________________________________17
12. Troubleshooting______________________________________________19
13. Spare parts ___________________________________________________20
14. Warranty _____________________________________________________21

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GENERAL INFORMATION
!This is the safety alert symbol. It is used to alert you to
potential personal injury hazard. Obey all safety messages
that follow this symbol to avoid possible injury or death.
The chapter Operation is intended for homeowners, heating
contractors, plumbers and electricians.
The chapter Installation is intended for heating contractors,
plumbers and electricians only.
1.1 Symbol key
1.1.1 Layout of safety information
DANGER: Electrocution
Before any work on the appliance,
disconnect all poles from the power
supply.
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1 Symbol (see 1.1.2 “Symbols”, below)
2 Keyword (see 1.1.3 “Keywords”, below)
3 Description (see 1.1.2 “Symbols”, below)
4Informationtext
1.1.2 Symbols
Symbol Description
Injury
Electrocution
Burns or scalding
!Other situations

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SAFETY PRECAUTIONS
1.1.3 Keywords
KEYWORD
DANGER The keyword DANGER indicates information that
must be observed, otherwise serious injury or
death will result.
WARNING The keyword WARNING indicates information that
must be observed, otherwise serious injury or
death may result.
CAUTION The keyword CAUTION indicates information that
must be observed, otherwise relatively serious or
light injuries may result.
2. Safety precautions
!Please read and follow these instructions. Failure to
follow these instructions could result in serious bodily
injury or death.
The unit must be installed by a licensed electrician and plumber.
The installation must comply with all national, state and local
plumbing and electric codes.
Service of the unit must be performed by qualified service
technicians.
Before proceeding with any installation, adjustment, alteration, or service of this unit, all circuit breakers
and disconnect switches servicing the unit must be turned off.
Failure to do so could result in serious personal injury or death.
DANGER: Never remove the unit's cover unless the electricity servicing the unit is turned off. Failure to do
so could result in personal injury or death.
WARNING: The unit must be properly grounded. Failure to electrically ground the product could result in
serious personal injury or death.

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REGISTER YOUR PRODUCT
DANGER: Water temperatures over 125°F (52°C) can cause severe burns instantly or death from scalding.
A hot water scalding potential exists if the output from the
unit is too high. Households with small children, disabled or
elderly persons may require that a mixing valve be installed to
deliver water temperatures of 120°F (49°C) or lower to prevent
possible injury from hot water.
3. Register your product
You must register this product within 90 days of purchase
on our web site in order to activate the standard warranty
or to be eligible for the extended warranty. Go to our web site at
www.stiebel-eltron-usa.com and click on register your product.
Before beginning the registration process, we suggest that you
gather the necessary information which will be as follows:
Type, Example: Mini 3-1 (from the white label that is on the right
side of the unit)
Number listed after "Nr."
Place of Purchase
Purchase Date
First & Last Name
Email address
Physical Address
Phone Number
If you have any questions concerning the registration process or
warranty options, please contact Stiebel Eltron USA directly at
800.582.8423.

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TEMPERATURE INCREASE ABOVE AMBIENT WATER TEMPERATURE
4. Temperature increase above ambient water temperature
Temp. rise above incoming water temp. (°F) Temp. rise above incoming water temp. (°C)
GPM l/m
Unit Heating Capacity 0.32 0.42 0.48 0.53 0.69 0.85 1.06 1.14 1.2 1.6 1.8 2.0 2.6 3.2 4.0 4.3
Mini 2-1*1.8 kW @110–120 V 39 ------- 22 - - - - - - -
Mini 2.5-1 2.4 kW @110–120 V -39 34 33 24 --- -22 19 17 13 - - -
Mini 3-1 3.0 kW @110–120 V -49 43 41 30 --- -27 24 22 17 - - -
Mini 3.5-1 3.5 kW @110–120 V -57 50 45 35 --- -31 28 25 19 - - -
Mini 4-2 3.5 kW @220–240 V -57 50 45 35 --- -31 28 25 19 - - -
Mini 6-2 5.7 kW @220–240 V -----46 37 34 -----25.5 20.4 19.0
*Mini 2-1 is internally restricted to 0.32 gpm (1.2 l/min)

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TECHNICAL DRAWINGS
5. Technical drawings
A
5/
58
” (143 mm)
3
/
16
” (4,8 mm)
1/
316 ” (30 mm)
4¾” (120 mm)
7 ½ ” (190 mm)
3¾” (95mm)
1
2
4
31 Hot water connection
2 Cold water connection
3 Filter screen
4 Mounting holes
13/16 ” (20 mm)
6½” (165 mm)
3 ¼ ” (82 mm)
3/8” O.D.
flex connector
A

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TECHNICAL DRAWINGS
B
B
B
B

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TECHNICAL DRAWINGS
C
C
C26_02_05_0010
5
6
7
89
10
5 Electrical junction box
6 Water supply line
7 Sink
8 Cold valve (right)
9 Hot valve (left)
10
Shut off valve
D
D
V >
p>
LN
LNGND
Mini™2-1/2.5-1
3-1/3.5-1
L1 L2 GNDMini™4-2/6-2

10 | Mini™Series Electric Tankless Water Heaters www.stiebel-eltron-usa.com
OVERVIEW
!This manual must be read carefully before attempting
to install the Mini 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 wa-
ter. Failure to comply with the installation and operating instruc-
tions 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 any additional installation manu-
als, please call our technical service line on 800.582.8423 (USA and
Canada only). If you are calling from outside the U.S. Or Canada,
please call usa 413.247.3380 and we will refer you to a qualified
Stiebel Eltron service representative in your area.
6. Overview
6.1 General Description
The Mini tankless water heater differs from conventional storage
type water heaters in several ways. It does not store hot water.
Instead, water is heated instantaneously as it flows through the
unit. The powerful heating elements are activated by a flow
switch as water is drawn from a hot water faucet connected to
the Mini. Due to the absence of stand-by losses, the Mini offers
greater energy efficiency than storage type water heaters. The
unit will continuously supply hot water as long as the faucet is
open.
The temperature of the hot water delivered by the Mini depends
on the wattage of the heating element, the temperature of the
incoming cold water, and the water flow rate through the unit.
In order for the Mini to operate properly, it must be carefully
matched to the application.
In case you have questions regarding the way you plan to use the
Mini, 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 413.247.3380. You can also email us at
[e-mail] or fax us at 413.247.3369.

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OVERVIEW
The Mini can be used for hand washing type applications in the
U.S. and Canada:
– Restroom sinks in commercial/industrial facilities and homes
– Kitchen areas in commercial /industrial facilities and homes
– Cabins
– Special uses in photo developing shops, laboratories etc.
The Mini can also be used for whole apartments and homes
in warm climate zones such as the Caribbean region, Central
America and Mexico due to the higher ambient water
temperatures.
6.2 Important information before supplying
power to unit
Air in the cold water pipe will destroy the Advanced Direct Coil™heating system of the Mini. If the water supply to the
Mini 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 unit is used again.
»1. Turn off circuit breaker.
»2. Open a hot water tap downstream of the unit for as long as
is necessary for the unit and the cold water pipe to be free of
air.
»3. Turn on circuit breaker.
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.

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OVERVIEW
6.3 Hot water output using required aerators
Model Wattage at max
rated voltage
Typical hot water
output with required
aerator installed†
Mini 2-1*1.8 kW 0.32 gpm (1.2 l/min)
Mini 2.5-1 2.4 kW 0.50 gpm (1.9 l/min)
Mini 3-1 3.0 kW 0.50 gpm (1.9 l/min)
Mini 3.5-1, 4-2 3.5 kW 0.66 /0.50 gpm (2.5 /1.9 l/min)
Mini 6-2 5.7 kW 1.0 gpm (3.8 l/min)
All Mini models ship with appropriately sized pressure
compensating flow-reducer/aerators that must be installed.
* Mini 2-1 is internally restricted to 0.32 gpm (1.2 l/min)
† Mini 2-1 ships with a 0.35 gpm (1.3 l/min) aerator
† Mini 2.5-1, 3-1 ship with a 0.5 gpm (1.9 l/min) aerator
† Mini 3.5-1, 4-2 ship with 2 aerators, one must be installed. Install
the 0.66 gpm aerator and test the water temperature. If the
water is not warm enough, remove the 0.66 gpm aerator and
install the 0.5 gpm aerator in its place.
† Mini 6-2 ships with a 1.0 gpm (3.8 l/min) aerator
6.4 Incorrect use
The following are not permitted and will void the factory warranty:
- Installation of the appliance where it is at risk from frost
- Installation in rooms where the appliance is at risk from
explosions as a result of dust, gases or vapors
- Ignoring safety clearances and safety zones
- Incorrect power connection
- Operation of the appliance without water flowing through the
unit, or with air in the lines (See section 8, “Initial start-up”,
pg. 16)
- Operation of the unit with the cover off
- Heating liquids other than potable water
6.5 First steps to be taken in the event of
malfunction
WARNING: Always shut off power and water to the unit prior to removing the filter screen. Failure to do so may
cause serious bodily injury or death.
»Check the circuit breaker
»Check the filter screen for scale blockage or dirt accumulation.
(See section 12, “Troubleshooting”, pg. 19.)

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INSTALLATION INSTRUCTIONS
6.6 Maintenance and care
!Maintenance work, such as checking electrical safety, may
only be carried out by a qualified installer.
WARNING: Always shut off power and water to the unit prior to removing the filter screen. Failure to do so may
cause serious bodily injury or death.
Regularly clean and descale the filter screen located in the cold water
inlet connection and if necessary replace. Always shut off power and
water to the unit prior to removing the filter screen.
A damp cloth is sufficient for cleaning of the unit's housing. Do not
use any abrasive or corrosive cleaning agents.
7. Installation instructions
Keep these instructions carefully and pass them on to your successor in the event of a change in ownership, in
the event of maintenance and possible repair work they should be
passed to the qualified installer for his or her reference.
7.1 Mounting the unit
!Unit must be installed with the plumbing connections
pointing downward or upward only.
WARNING: Do not install unit where it would routinely be splashed with water. Electric shock or death may result.
»1. Install Mini as close as possible to the hot water draw-off
point, for example, directly underneath the sink or next to the
shower stall.
»2. Install Mini 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 plastic cover by removing screws located on the left
and right sides of the unit B.
»5. Remove plastic backplate by pulling on the tab with a
screwdriver B.
»6. Mount backplate securely to wall by putting two screws
through mounting holes A B .
»7. Snap unit back onto mounting plate B.
»8. Reinstall cover with screws on left and right side of unit B.

14 | Mini™Series Electric Tankless Water Heaters www.stiebel-eltron-usa.com
INSTALLATION INSTRUCTIONS
7.2 Plumbing connections
NOTE: If soldering near the unit is necessary, please direct the flame away from the housing of the unit in order to
avoid damage. Excessive heat from soldering on copper pipes near
the Mini may cause damage. All plumbing work must comply with
national and applicable state and local plumbing codes.
»1. All plumbing work must comply with national 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. Install isolating valve in cold water line as shown in
illustration C. This allows the unit to be isolated for
maintenance purposes.
»5. Cold water connection (inlet) is on the right side of the unit,
hot water connection (outlet) is on the left side of unit.
»6. Tankless water heaters such as the Mini are not required
to be equipped with a Pressure and Temperature Relief Valve
(except in Massachusetts). If the local inspector will not pass
the installation without a P+T valve, it should be installed on
the hot water outlet side of unit.
»7. The Mini is designed for connection to a braided stainless
steel hose with a 3/8˝ O.D. tube outlet.
»8. When all plumbing work is completed, check for leaks and
take corrective action before proceeding.
7.3 Electrical connection
WARNING: Before beginning any work on the electric installation, be sure that the main circuit breaker panel
switch is “off” to avoid any danger of electric shock. Failure to do
so may result in serious injury or death. All mounting and plumbing
must be completed before proceeding with electrical hook-up.
Where required by local, state or national electrical codes, the
circuit should be equipped with a ground fault interrupter.
WARNING: As with any electric appliance, failure to electrically
ground unit may result in serious injury or death.
CAUTION: Installing a Mini 2-1, Mini 2.5-1, Mini 3-1, or Mini
3.5-1 on a 208 V or 220–240 V circuit will destroy the heating
element. This is considered improper installation and will void
your factory warranty.

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INSTALLATION INSTRUCTIONS
7.3.1 Wiring
For 120 V units, the brown wire of the pigtail should be hooked up
to L (Load/Live), the blue wire to N (Neutral), and the green/yellow
wire to the ground GND.
For 208/240 V units, the brown wire of the pigtail should be hooked
up to L1, the blue wire to L2, and the green/yellow wire to the
ground GND.
7.3.2 Voltage
Model Voltage
Mini 2-1 110–120 V
Mini 2.5-1 110–120 V
Mini 3-1 110–120 V
Mini 3.5-1 110–120 V
Mini 4-2 220–240 V, 208 V
Mini 6-2 220–240 V, 208 V
1. All electrical work must comply with national and applicable state
and local electrical codes.
2. The Mini should be connected to a properly grounded dedicated
branch circuit of proper voltage rating. In installations with several
Mini units, each unit requires an independent circuit. Please refer to
the technical data table for the correct wire and circuit breaker size.
3. The open ends of the “pigtail” must be feed into an electrical
junction box. Then feed wires through strain relief clamp and tighten
clamp down on wire.
4. Reinstall plastic cover.

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INITIAL START-UP
8. Initial start-up
!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 plastic cover must be installed before the circuit
breaker is turned on.
2
1
9. Water heater hand over
Explain the functions of the unit to the user and familiarize him or
her with its use.
Important instructions:
»Draw the user’s attention to possible hazards (scalding).
»Hand over these instructions for future reference.
»In order to obtain a proper temperature at a single spout
mixer-type faucet, restrict cold water flow to faucet by partially
closing the cold water shut-off valve under the sink until cold
water and hot water flow rates are approximately the same.
10. Normal maintenance
!CAUTION: Other than the filter screen, the Mini does not
contain any parts serviceable by the lay person. In case
of malfunction please contact a licensed plumber or electrician.
Stiebel Eltron Mini tankless heaters are designed for a very long
service life. Actual life expectancy will vary with water quality
and use. 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 Mini 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. Clean screen
and put the screen back into its original position.

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TECHNICAL DATA
11. Technical data
Mini™2-1*Mini™2.5-1 Mini™3-1 Mini™3.5-1 Mini™4-2 Mini™6-2
Part number 231045 232098 220816 232099 222039 220817
Electrical data
Phases 1 - 50/60 Hz
Voltage1110–120 V 110–120 V 110–120 V 110–120 V 220–240 V 208 V 220–240 V 208 V
Wattage 1.8 kW 2.4 kW 3.0 kW 3.5 kW 3.5 kW 2.6 kW 5.7 kW 4.3 kW
Amperage draw 15 A 20 A 25 A 29 A 15 A 13 A 24 A 21 A
Min. recommended circuit breaker size215 A 20 A 25 A 30 A 15 A 25 A
Min. recommended wire size3(copper) 14 AWG 12 AWG 10 AWG 10 AWG 14 AWG 10 AWG
Connections
Water connection4⅜ O.D. flex connector or ⅜ compression fitting
Application limits
Max. permissible pressure 150 psi (10 bar)
Recommended inlet temperature 41–77 °F (5–25°C)
Minimum water flow to activate unit 0.21 gpm (0.8 l/m)0.40 gpm (1.5 l/m)0.40 gpm (1.5 l/m)0.40 gpm (1.5 l/m)0.40 gpm (1.5 l/m)0.77 gpm (2.9 l/m)
*Mini 2-1 is internally restricted to 0.32 gpm (1.2 l/min).
1Nominal mains voltage is 110–120 V and 220–240 V.
2This is our recommendation for overcurrent protection sized at 100% of load. Check local codes for compliance if necessary.
Tankless water heater are considered a non-continuous load.
3Copper must be used. Conductors should be sized to maintain a voltage drop of less than 3% under load.
4For use with cold water supply only.

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TECHNICAL DATA
Mini™2-1*Mini™2.5-1 Mini™3-1 Mini™3.5-1 Mini™4-2 Mini™6-2
Miscellaneous
Heating element Nichrome wire
Color White
Included pressure compensating flow
reducer/aerator that must be installed
0.35 gpm (1.3 l/min) 0.5 gpm (1.9 l/min) 0.5 gpm (1.9 l/min) 0.66 gpm (2.5 l/min)
0.5 gpm (1.9 l/min)
0.66 gpm (2.5 l/min)
0.5 gpm (1.9 l/min)
1.0 gpm (3.8 l/min)
Dimensions
Height 6½ (143 mm)
Width 7½ (190 mm)
Depth 3¼ (82 mm)
Weights
Weight 3.3 lbs (1.5 kg)
Mini 3.5-1, 4-2 ship with 2 flow-reducer/aerators, one must be installed. Install the 0.66 gpm aerator and test the water temperature. If
the water is not warm enough, remove the 0.66 gpm aerator and install the 0.5 gpm aerator in its place.

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TROUBLESHOOTING
12. Troubleshooting
ESymptom Possible cause Solution
No hot water
despite fully
opened hot
water faucet.
No electrical power.Check the circuit breaker and
check voltage at the wiring block.
The activation flow rate needed to
turn on the heating element has
not been reached.
– Clean filter screen
– Clean aerator installed at faucet
Safety cut out tripped – Turn circuit breakers off
– Open hot valve to release
pressure from the unit
– Reset safety pressure cut out E
– Turn circuit breakers on
Safety pressure
cut out
DANGER: Electrocution
Do not attempt to reset the safety pressure cutout of
this water heater unless power to the unit has been
completely shut off at the circuit breakers.

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SPARE PARTS
13. Spare parts
1
23
4
Spare Part (all Mini™ models) Item no.
1 Front cover 271010
2 Rear housing 271011
3 Filter screen 272884
4 Plumbing connections 272777
5 O-rings (not shown) 083043