Bosch AE12 User manual

Installation and Operating instructions
Electric water heaters
AE 12
en Installation Manual and Operating Instructions 2
es Instrucciones de instalación y funcionamiento 17
fr Instructions d'installation et d'utilisation 34
6 720 800 531 (2011/09) US
IMPORTANT: This booklet should be given to the customer after installation and demonstration.
For Service & Installation contact:
BOSCH Thermotechnology Corp.
50 Wentworth Avenue, Londonderry
NH 03053
Phone: [phone]
www.bosch-climate.us

Table of contents
6 720 800 531 (2011/09)
2
Table of contents
1 Explanation of Symbols and Important Safety
Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1 Explanation of symbols . . . . . . . . . . . . . . . 3
1.2 Important Safety Instructions . . . . . . . . . . 3
2 Information about the heater . . . . . . . . . . . . . . . 4
2.1 Disclaimer . . . . . . . . . . . . . . . . . . . . . . . . . 4
2.1.1 Approval number . . . . . . . . . . . . . . . . . . . . 4
2.2 Technical identification code . . . . . . . . . . 4
2.3 Model name and number identification . . 4
2.4 Package contents . . . . . . . . . . . . . . . . . . . 4
2.5 General description . . . . . . . . . . . . . . . . . . 5
2.6 Function . . . . . . . . . . . . . . . . . . . . . . . . . . 6
3 Regulations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
4 Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
4.1 Important information . . . . . . . . . . . . . . . . 8
4.1.1 Freeze prevention . . . . . . . . . . . . . . . . . . . 8
4.2 Installing the AE 12 . . . . . . . . . . . . . . . . . . 8
4.3 Water connections . . . . . . . . . . . . . . . . . . 9
4.3.1 Water quality . . . . . . . . . . . . . . . . . . . . . . . 9
4.4 Electrical connections . . . . . . . . . . . . . . . 10
4.5 Securing the unit to the wall . . . . . . . . . . 11
4.5.1 Deciding the position . . . . . . . . . . . . . . . 11
4.5.2 Deciding the wiring route . . . . . . . . . . . . 11
4.5.3 Mounting on the wall . . . . . . . . . . . . . . . 12
5 Starting up the AE 12 . . . . . . . . . . . . . . . . . . . . 13
5.1 Sink . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
5.2 Adjusting the flow . . . . . . . . . . . . . . . . . . 13
5.3 Appendix Flow vs. Temperature
Setting Guide . . . . . . . . . . . . . . . . . . . . . . 14
6 Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . 15
6.1 For the Installer . . . . . . . . . . . . . . . . . . . . 15
6.2 For the User . . . . . . . . . . . . . . . . . . . . . . 15
7 Interior components and parts list . . . . . . . . . 16

Explanation of Symbols and Important Safety Instructions
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1 Explanation of Symbols and Important Safety Instructions
1.1 Explanation of symbols
Warnings
Signal words at the beginning of a warning are used to
indicate the type and seriousness of the ensuing risk if
measures for minimizing damage are not taken.
•NOTE indicates that minor damage to property may
occur.
•CAUTION indicates possible minor to medium
personal injury.
•WARNING indicates possible severe personal injury.
•DANGER indicates that severe personal injury may
occur.
Important information
Additional symbols
1.2 Important Safety Instructions
When using this electrical equipment, basic safety
precautions should always be followed, including the
following:
BRead and follow all instructions.
BThis appliance must be grounded.
BDisconnect this product from the electrical supply
before cleaning, servicing or removing the cover.
BTo reduce the risk of injury, close supervision is
necessary when the product is used near children or
elderly persons.
BWarning: Indoor installation only, where it will NOT be
exposed to freezing.
BWarning: Do not install a check valve or any other
types of back flow preventer within six feet of the cold
water inlet.
BThe electrical installation must conform to current
National Electrical Codes.
BWarning: Do not switch the heater on if you suspect
that it may be frozen. Wait until you are sure that it
has completely thawed cut.
BThe AE 12 is designed to heat potable cold water for
domestic purposes. Contact Bosch
Thermotechnology before specifying or installing the
appliance in any other application.
Additional Canadian Safety Instructions
•A green terminal (or wire connector marked "G", "GR",
"GROUND", or "GROUNDING") is provided within the
control box. To reduce the risk of electric shock,
connect this terminal or connector to the grounding
terminal of the electric service of supply panel with a
continuous copper wire in accordance with the
Canadian Electrical Code, Part I.
•This product shall be protected by a Class A ground
fault circuit interrupter.
Safe these instructions
BKeep this guide in a safe place once your AE 12 unit
has been installed.
BYou may need to refer to it for general instructions or
future maintenance.
Warnings are indicated in the text by a
warning triangle and a gray background.
In case of danger due to electric shock, the
exclamation point on the warning triangle is
replaced with a lightning symbol.
Important information that presents no risk
to people or property is indicated with this
symbol. It is separated by horizontal lines
above and below the text.
Symbol Meaning
BSequence of steps
→ Cross-reference to other points in this
document or to other documents
•Listing/list entry
–Listing/list entry (2nd level)
Table 1

Information about the heater
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2 Information about the heater
2.1 Disclaimer
2.1.1 Approval number
Commonwealth of Massachusetts
As a condition of installing this product in the
Commonwealth of Massachusetts a pressure relief valve
shall be installed on the cold water side, by a licensed
plumber MGL 142 Section 19.
(Approval number: P1-09-25).
2.2 Technical identification code
US Electronic Instantaneous
12 Maximum output (kW)
MMechanical temperature control
WWall hung
IIndoor
HHorizontal installation
BWater connections
2.3 Model name and number
identification
2.4 Package contents
•Electric water heater
•4 No. 8 wood screws
US 12 M W I H B
Table 2
Model Name Model Number
AE 12 US 12 M W I H B
Table 3

Information about the heater
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5
2.5 General description
Fig. 1
1Mouting hole
2Heat exchanger tube
3Control P.C.B
4Heating elements
5Terminal block
6Cable rear entry
7Ground stud
8Cable clamp
9Cable side entry
10 Neon light
11 Hi temp thermal cut-out (manual re-set)
12 Cover fixing screw
13 Flow switch
6720646914-01.1V
1 2 3
4
5
6
7
8
9
10
11
12
13
Outlet Inlet

Information about the heater
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2.6 Function
•Water comes in through the cold water inlet.
•The flow switch senses water is passing through the
unit. If it detects more than the pre-set level, the
unit’s heating the elements switch on. This is shown
by the neon light glowing.
•The water is heated instantly as it pas ses through the
copper heat exchanger tube.
•The unit is Thermostatic i.e. it will switch the
elements on and off in order to maintain a constant
outlet temperature.
The temperature of the water coming out of the unit
depends on:
•The voltage of the electrical supply,
•The temperature of the incoming water.
•The setting of the temperature dial.
A high flow rate can also negatively effect the hot water
temperature.
Depending on the region of the country, the temperature
of the water supply can vary from 40°F in winter to about
70°F in the summer, with an average of about 50°F.
Extreme weather conditions can cause the inlet
temperature to go outside these boundaries, making it
necessary to adjust the Temperature Adjustment
Spindle and/or the inlet water flow
Manual reset thermal cut-out
•The unit has one double pole thermal cut out which is
mounted on the heat exchanger tube.
•When tripped the cut out needs to be reset manually
inside the unit.
•The cut-out will trip only in exceptional circumstances
(Fig. 2). Call your service person or Bosch
Thermotechnology Corp. if this happens frequently.
Fig. 2
AThermal cut out
The heater is designed for cold water supply
only. Do not supply with pre-heated water.
WARNING:
BAlways switch off the electrical supply to
the unit before you remove the cover.

Regulations
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3 Regulations
Any local by-laws and regulations pertaining to
installation and use of electric water heater appliances
must be observed. Please refer to the laws that should
be attended in your country.
•The electrical installation must conform to current
National Electrical Codes.
•To reduce the risk of electrical shock, connect this
terminal or connector to the grounding terminal of the
electrical service of supply panel with a continuous
copper wire in accordance with the Canadian
Electrical Code, Part I.
•This product shall be protected by a Class A ground
fault circuit interrupter.
•In the Commonwealth of Massachusetts a licensed
plumber or electrician must perform the installation.
(Approval number: P1-09-25).
•In the Commonwealth of Massachusetts a pressure
relief valve shall be installed on the cold water side by
a licensed plumber. (MGL 142 Section 19, Approval
number P1-09-25).
•The unit must be wired by a qualified electrician, in
accordance with the current version of the National
Electrical Code US) or Canadian Electric Code
(Canada).
•When the heater is not within sight of the electrical
circuit breakers, a circuit breaker lockout or
additional local means of disconnection for all non-
grounded conductors must be provided that is within
sight of the appliance. (Ref NEC 422.31.).
•The power cable size and the installation must be in
accordance with the Canadian Electrical Code, C22.1-
02.
WARNING:
California Proposition 65 lists chemical
substances known to the state to cause
cancer, birth defects, death, serious illness
or other reproductive harm. This product
may contain such substances, be their
origin from fuel combustion (gas, oil) or
components of the product itself.

Installation
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4 Installation
4.1 Important information
Please follow these instructions. Failure to follow
instructions may result in:
•Damage or injury.
•Improper installation/operation.
•Loss of warranty.
4.1.1 Freeze prevention
Introduction
Please note that the installation manual states that the
water heater must not be installed in a location where it
may be exposed to freezing temperatures. If the heater
must be left in a space that is likely to experience
freezing temperatures, all water must be drained from
the heater.
Freeze damage is not covered under the warranty.
Draining the heater
Due to the shape of the heat exchangers and connecting
pipe, it is extremely difficult to get all of the water out of
the heater. Follow the procedure below to best minimize
the chance of freezing:
BDisconnect electric supply.
BDisconnect cold and hot water pipes from fittings on
bottom of heater. Allow water to drain out (have a
catch basin ready).
BAfter allowing all water to drain out, the heater should
be blown out with low pressure compressed air to
remove as much water as possible from water heater
modules. Bursts of air work better than continuous
flow.
Remember, these suggestions are only made to help
minimize the potential for freeze damage and are not to
be construed as the guaranteed method for dealing with
freeze possibilities.
4.2 Installing the AE 12
To operate correctly the unit needs the following
running pressures:
Sink
•Min: 10 psi (0,7 bar)
•Max: 150 psi (10,3 bar)
DANGER: Risk of electric shock!
BFor safety reasons, disconnect the power
supply to the heater before any service or
testing is performed.
WARNING:
BThis heater must be electrically grounded
in accordance with the most recent
edition of the National Electrical Code.
NFPA 70. In Canada, all electrical wiring
to the heater must be in accordance with
local codes and the Canadian Electrical
Code, CSA C22.1 Part 1.
DANGER:
BThe installation must only be performed
by a qualified person in accordance with
these instructions.
BBosch Thermotechnology Corp. is not
responsible for improperly installed
appliances.
WARNING:
BThe heater must only be mounted in a
vertical position with the water fittings
located at the bottom of the heater.
Under no circumstances should the
heater be mounted differently.
WARNING:
BELECTRICITY IS EXTREMELY
DANGEROUS. TAKE EXTRA
PRECAUTIONS AND ENSURE ALL
CIRCUIT BREAKERS ARE OFF BEFORE
PERFORMING ANY WORK TO THE
HEATER.
Use of agents like anti-freeze are not
allowed as they may cause damage to the
water heater’s internal components.
WARNING:
BDo not install the AE 12 in a room where
there is a chance of freezing.
NOTE:
BRead entire instructions.
BCheck the pressure of the main water
supply.

Installation
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4.3 Water connections
BThe unit should be connected directly to the main
cold water supply and not to pre- heated water. The
unit should be installed with service valves on both
the inlet and outlet. These valves can be used to turn
off the water supply to the unit if it needs servicing, or
to reduce the water flow if it is too high.
BWe recommend that you use ½" copper or high
pressure flex connections.
BUse Teflon tape for sealing pipe threads. Do NOT use
pipe dope.
BRemember to keep the hot water pipe runs as short
as possible. In some cases it may be worth fitting a
second unit to serve an additional fixture.
BThe inlet and outlet are clearly marked on the unit.
They each have a ½" NPT connector.
BIf the unit is to supply more than one sink, a similarly
flow restricted aerator should be used at each tap. If
not, the highest flowing outlet will take all the water
under dual usage.
BIf the unit is to supply a sink, we recommend that you
use aerators, which you can get from your local
distributor/dealer.
BAfter the unit has been plumbed in, and before you
wire it, flush it with water to remove any debris or
loose particles. Failure to do so may make the unit
inoperable.
4.3.1 Water quality
Water quality can have an impact on appliance longevity
and may not be covered under the manufacturer's
warranty.
BFor water analysis data call your local water
department, or if on a well, have well water analyzed
periodically.
If water quality exceeds one or more of the values
specified below, Bosch recommends consulting a
local water treatment professional for water
softening/conditioning options.
As a condition of installing this product in
the Commonwealth of Massachusetts a
pressure relief valve must be installed on
the cold water side by a licensed plumber.
MGL 42 Section 19.
WARNING:
BThe unit must be installed by a qualified
electrician.
BThe unit must be grounded.
BConnect the unit to power.
Description Max. Levels
pH pH 6.5 - 8.5
TDS (total Dissolved mg/l or ppm 500
Total hardness mg/l or ppm 100
Aluminum mg/l or ppm 2.0
Chlorides mg/l or ppm 250
Copper mg/l or ppm 1.0
Iron mg/l or ppm 0.3
Manganese mg/l or ppm 0.05
Zinc mg/l or ppm 5.0
Table 4

Installation
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4.4 Electrical connections
BStrip back the insulation on the power wires about 3/
8". Any insulation on the ground should be stripped
back about 3/4".
BFeed the cable through the cover bottom or backplate
entry grommets, as appropriate.
BConnect the cables to the terminal block and ground
stud (Fig. 3):
Fig. 3 Cable termination
BMake sure that all the terminal block screws are
tightened securely. Loose connections can cause
wires to neat up.
BMake sure that the ground wire is wrapped around its
terminal stud and into the saddle washer. The nut
should be tightened securely.
BAttach the front cover and tighten the retaining
screws.
Model
Rated
Voltage
(V)
Rated
Current
(A)
Recommend
Wire Size
(AWG)
US12 240 50 6
Table 5
NOTE:
When the AE 12 is not within sight of the
electrical circuit breakers, a circuit breaker
lockout or additional local means of
disconnection for all non grounded
conductors must be provided that is within
sight of the appliance. (REF NEC 422.31)
Rubber
Sleeve
Ground