A.O. Smith Gen 8 Digital User manual

Mini Water Heater
Gen 8 Digital
EWH-40MINI2
User Guide

About A. O. Smith
Established in 1874, the A. O. Smith Water Products Company is a global leader in innovative water
technologies. With 21 fully-owned plants, they are currently the largest water heater manufacturer in the
world.
Over the years, A. O. Smith has gained the respect and support of homeowners, contractors, architects
and specifying engineers in over 60 countries by providing energy efficient hot and clean water
solutions.
What’s in the box?
2

Contents
Specifications ........................................................................................... 5
Safety Features ....................................................................................... 6
Product Features ...................................................................................... 6
Installation ................................................................................................. 9
Directions For Use .................................................................................... 13
Maintenance Instructions ....................................................................... 17
Troubleshooting ....................................................................................... 18
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Read Before Use
Before installation and use of this device, please read this manual carefully and keep it ready for future
reference.
Engage an experienced water heater installer. A. O. Smith and AOS Bath will not be held liable by any
damages or piping leakages caused by incorrect installations.
This heater is suitable for residential use. Any attempts to use it for commercial purposes will reduce the
heater lifespan. Once the heater has been installed, owners should run checks every 6 months and the
system should undergo maintenance every 3 years. If there are any operational irregularities, please
discontinue use of the heater immediately and call our company hotline.
Before any instances of heater repair and maintenance, users should disconnect the power supply. Any
modifications and repairs should only be handled by company approved technicians.
Heaters may cause serious scalding. Mix hot with cold water before showering or taking a bath.
If heater suffers from dry heating, any resultant steam and hot water may cause serious scalding. As a
result, users should ensure that the heater tank is always full of water. If dry heating occurs, immediately
cut off electrical & water supply and stop using the heater. Call our company service hotline and wait for
our approved technicians to do the necessary checks and repair.
For safety issues, do not change any of the settings of the pressure relief valve or temperature pressure
relief valve. Ensure all blockages are clear and install a drainage pipe to allow the overflow water to be
discharged into a floor drain.
Water produced by the heater is not potable and should not be consumed.
Any circuits, gauges, circuit breakers and wiring used for the heater must meet current ampere
requirements and be checked by approved technicians. Do not use damaged circuitry or an outdated,
loose, unstable power outlet for the heater. This will cause electrical shocks, fuses, fires, etc.
Heater electrical connections must be used in tandem with a dedicated power source located at a dry
area. Do not handle electrical points with wet hands. This may cause electrocution or physical damage to
self.
A white translucent colour to the water produced by the heater is considered normal. This is due to the air
pockets or foam caused by the pressure of dissolved air in water after heating.
Note: Incomplete compliance of this manual’s contents may cause fires, financial or property losses,
personal harm or death.
Warning: This is an electronic appliance and must be used with reliable connections.
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Specifications
Specifications
Rated volume (L)
40
Power (kW)
4.0
Voltage/Frequency (V/Hz)
220/50
Temperature range (
°C) 35-75±5
Rated water pressure (
MPa) 0.8
Max
-min inlet water pressure (MPa) 2.0/3.0
Inlet/outlet connection (inches)
½
Waterproof grade
IPX4
A. O. Smith reserves the right to
make product changes or
improvements at any time
without notice.
5
Dimensions
Length (mm)
880
Width (mm)
340
Height (mm)
350

Safety Features
Thermal Cut Out
The water heater employs a thermal cut out. In case any fault occurs and the water
temperature exceeds the highest preset limits, the switch rapidly cuts off the live and
neutral line for user’s safety.
Pressure Relief Valve
The safety valve will relive pressure automatically through droplets of water when
the system exceeds the rated pressure.
Product Features
Intelligent Maintenance Monitor (IMM)
IMM helps to prevent corrosion of the internal heater tank. The intelligent active
system releases protective ions into the tank, neutralizing aggressive corrosive ions in
the water.
Automatic Energy Saver (AES) (Patent ZL00112584.2)
The AES memory chip records up to 21 days of usage habits and automatically heats
water before users take a bath. During off peak periods, the heater goes into
energy saving mode.
6 MAX heating technology produces thrice as much hot water as a conventional
electric heater without consuming more energy.
6 MAX Heating (Patent ZL200820185859.4)
6
IMM

Blue Diamond Dual Elements (Patent ZL200510037670.1)
This water heater has two patented Blue Diamond heating elements which increase
heating efficiency by up to 50%.
Touch Control Panel
Access all modes of the water heater or reduce your water heating bills by turning
down your heater thermostat from the control panel.
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Hot Water Display
Temperature sensors in the heater provide a visual display of hot water from the
control panel.
Instant Heating (Patent ZL200820185859.4)
Intelligent sleep mode
The heater goes into power-saving mode after 3 minutes of inactivity.
The latest instant technology allows users to get hot water from an unheated tank
immediately, without consuming more energy.
Programmable Timer
The timer powers up the heater for you so you don’t have to turn it on manually. It
also switches your heater to energy saving mode when not in use.
Wireless remote
Program your heater with the wireless remote. The keys are identical to those on
the touch screen panel.

3 Year Full Warranty
With the highest manufacturing standards and strict quality control, we assure users
durability with a 3 year full warranty on the whole unit, the longest warranty in
Singapore.
3years
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High Efficiency Insulation
A polyurethane foam insulating layer without freon is used, which provides a good
insulation and reduces heat loss effectively.
Blue Diamond Tank (Patent US6303183)
Patented A. O. Smith Blue Diamond Tanks provide superior durability. The longest
lasting Blue Diamond tank in the world was used for 52 years.

Installation
CAUTION:
•Please wait for 30 minutes before using the heater for the first time.
•The heater should only be connected to a power source after a full installation which ensures
secure mounting, piping, wiring and filling of the tank with water.
•To prevent injuries from lifting heavy equipment, the water heater should be installed by at least
2 persons.
•The water heater must be installed by a qualified personnel.
Location
This water heater should be installed at a location that is close to a power source, floor drain and
water supply. As the water heater is in use, water may be discharged from the pressure relief valve,
so there must be a floor drain near the heater. When installing the water heater, be sure the water
inlet and outlet pipes are at the bottom of the heater. The system must not be installed vertically.
Mounting Procedures and Precautions
The surface for installation must be capable of supporting at least four times the weight of the water
heater when filled with water. If the water heater is not installed on the bearing wall or is mounted
on hollow brick wall, corresponding protective measures must be provided.
This water heater must be installed with the fixing accessories provided. The heater must be hung on
accessories which are fixed firmly or else the heater may dislodge and serious injuries will result.
Mounting Guidelines
Before drilling, ensure the right side of the
heater is at least 300mm away from the wall
so as to allow for easy maintenance access. If
the heater is installed above a false ceiling,
ensure a 500 x 500mm service access directly
below.
Use an electric drill with a Ø12mm drill bit to
drill two holes 100mm in depth. The holes must
be level. The space between the two holes
should be 380mm.
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Fit a plastic drill bit into the drilled holes and slowly twist the screws into the holes with an allen key.
Do not over tighten as it may cause the drill bits to break.
Place the screws through the square, top portion of the mounting plates and mount the heater on the
plates. Give the heater a firm downward tug to ensure the screws are lodged firmly against the
brackets.
CAUTION:
•The mounting accessories provided can only be used for solid walls, as shown in the drawing
above. Improper installation may cause the water heater to dislodge.
10
correct installation incorrect installation100mm depth
Electrical Connection
This water heater must be permanently connected to the electrical supply through a double pole
switch having a contact separation of at least 3mm in all poles incorporated in the fixed wiring. The
insulation of the fixed wiring must be protected by an insulating sleeving with a temperature rating
of at least 80°C.
Ensure the water heater is reliably grounded. The earth wire must be longer than the current carrying
conductors. The maximum power of this water heater is 5000W, hence a single dedicated power
supply circuit is proposed. On 5kW mode, the heater must be connected to a circuit of rated current
no less than 32A. If the wire diameter is 2.5m², the system must operate in 4kW mode.
Switching wattage modes
1. Use screwdriver to remove power adjustment switch cover
2. Turn rocker switch to ’0’ position as shown in the figure
3. Close cover and tighten screws to secure