Aqua Power AQM 2-1 Instruction Manual

OPERATION AND INSTALLATION
FUNCIONAMIENTO E INSTALACIÓN
MODE D’EMPLOI ET INSTALLATION
ELECTRIC TANKLESS 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
»AQM 21
»AQM 2.51
»AQM 31
»AQM 3.51
»AQM 42
»AQM 62
Conforms to ANSI/UL Std. 499
Certied to CAN/CSA Std. E335-1 & E335-2-35
Conforme a ANSI/UL Std. 499
Certicación con CAN/CSA Std. E335-1 & E335-2-35
Conforme à la norme ANSI/UL Std. 499
Certié à la norme CAN/CSA Std. E335-1 & E335-2-35
Tested and certied by WQA to NSF/ANSI372
for lead free compliance.
Probado y certicado por WQA NSF/ANSI 372 para
el cumplimiento de las regulaciones sin plomo.
Testé et certié 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
800.582.2213 (USA and Canada only). If you are calling from
outside the USA or Canada, please call and we will refer you to a
qualied Aqua Power® 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 _____________________________ 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 po-
tential 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
Before any work on the appliance, disconnect all
poles from the power supply.
13
4
2
1 Symbol (See section 1.1.2, “Symbols”, pg. 3)
2 Keyword (See section 1.1.3, “Keywords”, pg. 4)
3 Description
4 Information text
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 na-
tional, state and local plumbing and electric codes.
Service of the unit must be performed by qualied service
TECHNICIANS.
Before proceeding with any installation, adjustment, altera-
tion, or service of this unit all circuit breakers and disconnect
switches servicing the unit must be turned o. 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 o. 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 thermostat on the unit is set
too high. Households with small children, disabled or elderly
persons may require that the thermostat be set at 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: AQM 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 Aqua Power® USA directly
at 800.582.2213.

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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
AQM 2-1 1.8 kW @ 110–120 V 39 ------- 22 -------
AQM 2.5-1 2.4 kW @ 110–120 V - 39 34 33 24 --- -22 19 17 13 - - -
AQM 3-1 3.0 kW @ 110–120 V -49 43 41 30 --- -27 24 22 17 - - -
AQM 3.5-1 3.5 kW @ 110–120 V - 57 50 45 35 --- -31 28 25 19 - - -
AQM 4-2 3.5 kW @ 220–240 V -57 50 45 35 --- -31 28 25 19 - - -
AQM 6-2 5.7 kW @ 220–240 V -----46 37 34 -----25.5 20.4 19.0
* Note: AQM 2-1 is internally restricted to 1.2 l/min (0.32 gpm)

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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

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TECHNICAL DRAWINGS
C
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 o valve
D
V >
p!
LN
LNGND
Mini™2-1/2.5-1
3-1/3.5-1
L L GNDMini™4-2/6-2
AQM
Min
i
™
AQM
Mi
n
i
™
AQM

10 | AQM ELECTRIC TANKLESS WATER HEATERS WWW.APTANKLESS.COM
TECHNICAL DRAWINGS
!
This manual must be read carefully before attempting to
install the aqm 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 dam-
age, serious bodily injury and/or death.
!
Aqua Power®, Inc. will not be liable for any damages be-
cause of failure to comply with the installation and operat-
ing instructions outlined in this manual or because of im-
proper 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 o.
!
If you have any questions regarding the installation or op-
eration of this water heater, or if you need any additional
installation manuals, please call our technical service
line on 800.582.2213 (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 qualied Aqua
Power® service representative in your area.
6. Overview
6.1 General Description
The AQM tankless water heater diers from conventional
storage type water heaters in several ways. It does not store
hot water. Instead, water is heated instantaneously as it ows
through the unit. The powerful heating elements are activated
by a ow switch as water is drawn from a hot water faucet
connected to the AQM. Due to the absence of stand-by losses,
the AQM oers greater energy eciency 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 AQM
depends on the wattage of the heating element, the
temperature of the incoming cold water, and the water ow
rate through the unit. In order for the AQM to operate properly,
it must be carefully matched to the application.
In case you have questions regarding the way you plan to use
the AQM, please call our technical service line at 800.582.2213
(USA and Canada). For service outside the U.S. and Canada,
please call us at 413.247.3380. You can also e-mail us at
[e-mail] or fax us at 413.247.3369.

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OVERVIEW
The AQM 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 AQM 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 bare-wire heat-
ing system of the AQM. If the water supply to the AQM 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 o 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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TEMPERATURE INCREASE ABOVE AMBIENT WATER TEMPERATURE
6.3 Hot water output
Model Wattage at max
rated voltage
Typical hot water output
with required aerator
installed†
AQM 2-1*1.8 kW 0.32 gpm (1.2 l/min)
AQM 2.5-1 2.4 kW 0.50 gpm (1.9 l/min)
AQM 3-1 3.0 kW 0.50 gpm (1.9 l/min)
AQM 3.5-1 3.5 kW 0.66 gpm (2.5 l/min)
AQM 4-2 3.5 kW 0.66 gpm (2.5 l/min)
AQM 6-2 5.7 kW 1.0 gpm (3.8 l/min)
All AQM models ship with appropriately sized pressure
compensating ow-reducer/aerators that must be installed.
* AQM 2-1 is internally restricted to 0.32 gpm (1.2 l/min)
† AQM 2-1 ships with a 0.35 gpm (1.3 l/min) aerator
† AQM 2.5-1, 3-1 ship with a 0.5 gpm (1.9 l/min) aerator
† AQM 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.
† AQM 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 owing through
the unit, or with air in the lines (See section 8, “Initial start-
up”, pg. 16)
-Operation of the unit with the cover o
-Heating liquids other than potable water
6.5 First steps to be taken in the event of
malfunction
WARNING:
Always shut o power and water to the unit prior to remov-
ing the lter screen. Failure to do so may cause serious
bodily injury or death.

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TEMPERATURE INCREASE ABOVE AMBIENT WATER TEMPERATURE
»Check the circuit breaker
»Check the lter screen for scale blockage or dirt
accumulation. See section 12, “Troubleshooting”, pg. 19.
6.6 Maintenance and care
Maintenance work, such as checking electrical safety, may
only be carried out by a qualied installer.
WARNING:
Always shut o power and water to the unit prior to remov-
ing the lter screen. Failure to do so may cause serious
bodily injury or death.
Regularly clean and descale the lter screen located in the cold
water inlet connection and if necessary replace. Always shut o
power and water to the unit prior to removing the lter screen.
A damp cloth is sucient 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 qualied 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 AQM as close as possible to the hot water draw-o
point, for example, directly underneath the sink or next to
the shower stall.
2 Install AQM 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.

14 | AQM ELECTRIC TANKLESS WATER HEATERS WWW.APTANKLESS.COM
INSTALLATION INSTRUCTIONS
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.
7.2 Plumbing connections
NOTE:
If soldering near the unit is necessary, please direct the
ame away from the housing of the unit in order to avoid
damage. Excessive heat from soldering on copper pipes
near the aqm 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
ushed 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 AQM 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 AQM 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.

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INSTALLATION INSTRUCTIONS
7.3 Electrical connection
WARNING:
Before beginning any work on the electric installation, be
sure that the main circuit breaker panel switch is “o” 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 an AQM 2-1, AQM 2.5-1, AQM 3-1, or AQM 3.5-1
On a 208 V or 220–240 V circuit will destroy the heating ele-
ment. This is considered improper installation and will void
your factory warranty.
Voltage
AQM 2-1: 110–120 V
AQM 2.5-1: 110–120 V
AQM 3-1: 110–120 V
AQM 3.5-1: 110–120 V
AQM 4-2: 220–240, 208 V
AQM 6-2: 220–240, 208 V
1 All electrical work must comply with national and
applicable state and local electrical codes.
2 The AQM should be connected to a properly grounded
dedicated branch circuit of proper voltage rating. In
installations with several AQM 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 fed 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 ow 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 ow to faucet by
partially closing the cold water shut-o valve under the sink
until cold water and hot water ow rates are approximately
the same.
10. Normal maintenance
!CAUTION:
Other than the lter screen, the AQM does not contain any
parts serviceable by the customer. In case of malfunction
please contact a licensed plumber or electrician.
Aqua Power® AQM tankless 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 ow, 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 AQM has
a built in lter screen that should be cleaned from time to time.
In order to do this, turn o 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
AQM 2-1*AQM 2.5-1 AQM 3-1 AQM 3.5-1 AQM 4-2 AQM 6-2
Part number 612431 612432 612433 612434 612435 612436
Electrical data
Phases 1 - 50/60 Hz
Voltage 120 V 120 V 120 V 120 V 240 V 208 V 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 14.6 A 12.5 A 23.8 A 20.6 A
Min. recommended circuit breaker size 115 A 20 A 25 A 30 A 15 A 15 A 25 A 25 A
Min. recommended wire size 2(copper) 14 AWG 12 AWG 10 AWG 10 AWG 14 AWG 10 AWG
Connections
Water connection3⅜ 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)
0.4 gpm
(1.5 l/m)
0.4 gpm
(1.5 l/m)
0.4 gpm
(1.5 l/m)
0.4 gpm
(1.5 l/m)
0.77 gpm
(2.9 l/m)
* AQM 2-1 is internally restricted to 0.32 gpm (1.2 l/min).
1 Nominal mains voltage is 110–120 V and 220–240 V.
2 This 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.
3 Copper must be used. Conductors should be sized to maintain a voltage drop of less than 3% under load.
4 For use with cold water supply only.

18 | AQM ELECTRIC TANKLESS WATER HEATERS WWW.APTANKLESS.COM
TECHNICAL DATA
AQM 2-1*AQM 2.5-1 AQM 3-1 AQM 3.5-1 AQM 4-2 AQM 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 / 0.5 gpm (2.5 / 1.9 l/min) 0.66 / 0.5 gpm (2.5 / 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)
AQM 3.5-1, 4-2 ship with 2 ow-reducer/aerators, one must be installed. Install the 0.66 gpm aerator and test the water tempera-
ture. 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 ow rate needed to
turn on the heating element has
not been reached.
Clean lter screen or aerator.
Safety cut out tripped – turn circuit breakers o
– open Hot Valve to release pres-
sure from the unit
– reset safety pressure cut out
E
– turn circuit breakers on
Safety pressure
cut out

20 | AQM ELECTRIC TANKLESS WATER HEATERS WWW.APTANKLESS.COM
SPARE PARTS
13. Spare parts
1
23
4
Spare Parts (all AQM models) Item no.
1Frontcover 271010
2 Rear housing 271011
3Filterscreen 272884
4 Plumbing connections 272777
5O-rings(notshown) 083043