A.O. Smith EWH-10A2 User manual

EWH-10A2/10B2
Electric Wall Hung Water Heater
WATER HEATER
A.O.SMITH WATER PRODUCTS COMPANY.
INSTALLATION & OPERATION MANUAL

WATER HEATER
EWH-10 Electric Wall Hung Water Heater
EWH-10 Electric Wall Hung Water Heater
Congratulations on your purchase of a new,high quality wall-
hung water heater from A.O. Smith.Your heater is equipped
with technology and features that only a company
with over sixty years of experience can deliver .With the proper
care,your heater will deliver comfortable
hot water for years to come.
We are concerned about your safety
and ask you to read this manual thoroughly and
pay close attention to all
of the warning and information
contained inside.Be sure to keep these instructions for
future reference.
Thank you for buying an A.O.Smith brand water heater.

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WATER HEATER
EWH-10 Electric Wall Hung Water Heater
EWH-10 Electric Wall Hung Water Heater
Table of Contents
General Safety Information ................................................................................................................. 2
Physical Characteristics ...................................................................................................................... 3
Specifications ......................................................................................................................................... 3
Safety Features ..................................................................................................................................... 3
High Temperature Limit Control(High Limit) .......................................................................................... 3
Safety Valve .................................................................................................................................................. 3
Product Features .................................................................................................................................. 4
Thermostat .................................................................................................................................................. 4
Glass-lined Tank .......................................................................................................................................... 4
Thermal Insulation Layer ............................................................................................................................ 4
Anode Rod .................................................................................................................................................. 4
Installation Instruction ....................................................................................................................... 4
Installation procedure ................................................................................................................................. 5
Water Connection ...................................................................................................................................... 6
Power Connection ...................................................................................................................................... 6
Filling ........................................................................................................................................................... 6
Operation Instruction ......................................................................................................................... 7
Setting up Temperature ............................................................................................................................... 7
Operating ..................................................................................................................................................... 7
Note ............................................................................................................................................................. 7
Repair and Maintenance ..................................................................................................................... 7
Replacing Parts ............................................................................................................................................ 7
Maintenance ................................................................................................................................................ 8
Troubleshooting .................................................................................................................................... 8
Wiring Diagram .................................................................................................................................... 9
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WATER HEATER
EWH-10 Electric Wall Hung Water Heater
EWH-10 Electric Wall Hung Water Heater
Code Regulation: Power socket cannot be used unless it is well grounded.Do not use ungrounded
water heater.
General Safety Information:
★ A.O.Smith Company will not be liable for any damage resulting from incorrect installation
of this water heater. Only professionals recognized by A.O.Smith are allowed to install this
water heater for you.
★ Read this manual thoroughly, before installation and use.Failure to comply with these
instructions may cause serious harm and or property loss.
★ Hot water may cause serious scalding injury.Hot water must be mixed with cold water before
shower and washing.
★ If the power cord is damaged,only water heater manufacturer,its customer service or similar
professionals can replace it.
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WATER HEATER
EWH-10 Electric Wall Hung Water Heater
EWH-10 Electric Wall Hung Water Heater
EWH-10A2 Physical Characteristics EWH-10B2 Physical Characteristics
Figure 1
Table1-Specifications
Modle
EWH-10A2
EWH-10B2
10
10
~220V 50/60Hz
~220V 50/60Hz
2000W
2000W
(28~75)±5
(28~75)±5
0.8
0.8
7.5
7.5
Capacity
(L)
Input
(W)
Temp.Range
(℃)
Rated Water
Pressure(MPa)
Net Weight
(kg)
Voltage(V)/
Frequency(Hz)
High Limit: A manual-reset high limit cuts off power supply in case the thermostat becomes faulty
and Water becomes excessivecly hot.
Pressure-relief Safety Valve: This appliance has a pressure relief valve(see figure 6).It must be
installed in the inlet piping(blue).It has been factory set at 0.8 MPa and is nonadjustable. This Valve
relieves and discharges when the actual pressure in the piping exceeds this set rate.The discharge outlet
of this valve must face downward,and the discharged water must be piped into or within15 cm above
a suitable drain.Under any circumstances,the drain line cannot be blocked,and must be open to the
atmosphere. Please refer to figure 6 for water installation.
Safety Feature
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350
Indication Light
Temperature
Regulator
100
1/2 BSP Thread
〃
350
89
280
Indication Light
Temperature
Regulator
350
100 89
280
1/2 BSP Thread
350

Warning: Hot water in excess of 50℃ can produce scalding injury.Please be cautious when the
water is set exceeding 50℃, for the safety of your family and children in particular.
WATER HEATER
EWH-10 Electric Wall Hung Water Heater
EWH-10 Electric Wall Hung Water Heater
Installation Instruction
Product Features
Thermostat: The surface thermostat senses water temperature
fast and accurate.The outer knob is for setting water temperature
safely and conveniently.
Glass-lined Tank:
This A.O.Smith patent technique,developed 60 years ago, evenly coats specialty silicon frit onto the tank inner
surface. The frit coating is then fused to the steel at 850℃,forming a durable impact-resistant lining. Further,
this glass-lined tank has passed the100Κ-times cycle test per UL(Underwriter＇Laboratories) standard.Water
heater life is greatly prolonged as a result of its antirust and anti-scale feature.
Thermal Insulation Layer:This extra-thick insulation layer keeps temperature well and reduce heat loss
maximally.
Anode Rod Protection:
This anode rod is of stainless-steel core and can protect water tank and greatly prolong the life of water heater.
Water heater should be located close to electric power outler, floor drain and point of use. Because water may be
discharged from safety vavle,a suitable drain must exist near the water heater. Be sure to have the inlet and outlet
of the heater facing downward.
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Figure 2

WATER HEATER
EWH-10 Electric Wall Hung Water Heater
EWH-10 Electric Wall Hung Water Heater
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Warning: Be sure to use the provided mounting fixture for the installation of this heater.The heater
can be hung up only after the mounting fixture is firmly fixed and double-checked. Serious
damage and harm can result should the heater fall off from the wall.
Figure 3
Figure 4 - Hanger Installation
Installation Procedure:
●Make sure that the wall can withstand four times weight of
fully filled water heater.
●To locate the fixing bolts, make sure the heater front has
adequate c1earance to facilitate opening up the plastic
front cover for servicing or resetting the high limit when
necessary.
●Use 10mm drill bit to drill 2 holes of at least 70mm depth
in wall.The 2 holes should be in line horizontally. See figure 3
for distance specifications.
● Insert the nylon expansion tube into the drilled wall hole ,and screw the hook-bolt in slow speed.See
figure 4 for details.
● Ensure the length of hook-bot outside wall 5~10mm, and the hook be vertical.

WATER HEATER
EWH-10 Electric Wall Hung Water Heater
EWH-10 Electric Wall Hung Water Heater
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Caution: Provided mounting fixtures can only be used on solid cement wall. Inappropriate installation
may result in heater falling off.
Figure 5
Figure 6
EWH-10A2 Water Connection EWH-10B2 Water Connection
Water Connection:
Install the pressure relief safety valve in the
water inlet (blue) piping ; orient the arrow
pointer to the heater. Connect hot water pipe
to the red outlet,Piping connected to inlet and
outlet must be able to tolerate 1.0 MPa water
pressure and 98℃temperature. Make sure
suitable pipe thread sealant is used for all
connections to prevent leakage,In case that the
supplying water pressure is close to the safety
valve rating,install a pressure-reducing valve in
inlet piping with sufficient distance away from
the heater.See figure 6 for water connection
details.
EIectrical wiring:
This water heater has power wire and plug and readily connected.Just plug it into an according socket.
Make sure the water heater and the socket are appropriately grounded. Plus, the socket must be of good
quality to ensure good contact with the plug.
Filling:
After all the piping connection is done,fully open the hot-water faucet to fill until water flows.Check for
any leak. If it leaks,drain the heater completely,repair the leaking point,then re-fill the heater.

WATER HEATER
EWH-10 Electric Wall Hung Water Heater
EWH-10 Electric Wall Hung Water Heater
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Warning: Only qualified service technicians are allowed to conduct repair and maintenance .Incorrect
practice may cause serious harm and or property loss.
Caution: This appliance must be unplugged before being opened up or serviced.
Note: Use the Troubleshooting list as a guide to correct apparent problems before calling for repair
service.
Temperature setting:Adjust the temperature setting knob can set the water temperature.The‘OFF’mark
pointing at indication light position means the heater is off.Turning adjusting knob clock-wise ,a‘click’
sound can be heard;representing the temperature is being set;the bigger dot on the knob you turn to,the
higher temperature you get.
Operating:After making sure the heater is filled up,turn the power on.
When the indicating light is on,the heater is being heated; if the1ight goes off ,it means the heater has been
heated to the set temperature.
Note:During heating ,it is normal if there is water dripping through the safety valve outlet.Under normal
use,the safety valve lever should be opened periodically.If water flows,then the relief valve is in good working
condition ,if no water flows,then contact local customer service.
Operating Instructions
Repair and Maintenance
Replacing Parts
Heating element and anode rod: 1)unplug the water heater 2) close off the inlet valve 3)open up the
safety valve lever near the water inlet 4)open up the hot water faucet to let air enter to drain all the water in
the tank 5)remove the knob 6)remove the screw below the knob,take off the plastic front cover 7)remove the
two screws and take off the fixing bracket 8)unscrew the element-fixing nut,take out the heating element and
anode rod;note:rotate the heating element any angle 9)clean or replace the element or anode where neces-
sary 10)install new replacements by reverse sequence 11)re~fill the heater before being
used again.Note:element replacement must be of equivalent specifications as of the original.
Thermostat: 1)unplug the water heater 2)remove plastic front cover 3)disconnect wiring terminal
4)take off the thermostat 5)install new replacement by reverse sequence.Note:when re-installing the
thermostat,be sure to p1ace the temperature sensor into the sensing port of the heating element.

WATER HEATER
EWH-10 Electric Wall Hung Water Heater
EWH-10 Electric Wall Hung Water Heater
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Troubleshooting
Problem Possible Cause Solution
High Limit: 1)unplug the water heater 2)remove the plastic front cover 3)disconnect the wiring
terminal 4)take off the high limit 5)install new replacement by reverse sequence.
Maintenance:
● When necessary to completely drain the heater, close inlet valve,then open outlet valve (faucet),
lift safety valve lever, water flows out of the discharge line.
● Clean water tank periodically to remove scale. 1)shut off power 2)remove safety valve and inlet tube
3)connect the water heater outlet with supply piping(tap water);connect the heater inlet to floor drain
4)turn on the inlet valve fully to have the supplying(tap)water flush the tank,until the water runs clear
5)re- connect piping per figure6.
Warning∶ the discharged water may be hot,be cautious to prevent scalding injury.
Indication Light off
No hot water
Indication Light off
Water temperature too high
Indication Light on
No hot water
Water too hot
Piping connection leaks
Cover leaks
1)Heater is no plugged
2)No power in the wall socket
3)Control circuit or internal wiring error
1)High-limit activated
2)Thermostat faulty
Heating element(s) burnt
or internal wiring error
Thermostat set too high
Connection not sealed
Thank or parts leak
Contact customer service
Turn down adjusting knob
Re-connect piping,
must use thread sealant
Shut off power immediately
contact customer service
1)Contact customer service
2)Contact customer service
1)Plug the heater
2)Check the socket
3)Contact customer service

WATER HEATER
EWH-10 Electric Wall Hung Water Heater
EWH-10 Electric Wall Hung Water Heater
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Figure 7 - Wiring Diagram

A.O.Smith reserves the right to make product changes or improvements at any time without notice. 0.2k-06-2008
ADD:No.336,Yao Xin Avenue,NETDZ,NANJING,JIANGSU,P.R. CHINA
TEL : [phone] FAX: [phone]
P.C:210038Http://www.aosmith.com.cn
407092-003 Rev. 04
WATER HEATER
A.O.SMITH(CHINA)WATER HEATER COMPANY LTD.