Dewhot OD20DH User manual

20L Outdoor Fan Forced
Gas Geyser

Page 2 of 24 Dewhot | Gas geyser manual
Read these instructions carefully before operating the
gas geyser and familiarize yourself with the appliance
before connecting it to the gas cylinder. Keep these
instructions for future reference.
This appliance is manufactured to operate on LPG
only. Do not tamper or modify the appliance.
IF YOU SMELL GAS
1. Turn o the gas supply at the bottle
2. Extinguish all naked ames
3. Do not operate any electrical
appliances
4. Ventilate the area
5. Check for leaks as described in
this manual
6. If gas smell persists, contact your
dealer or gas supplier immediately
7. Do not modify the appliance
BURN-BACK
In the event of a burn-back, where the
ame burns back to the jet, immediately
turn the gas supply o at the gas cylinder.
After ensuring the ame is extinguished,
wait for I minute and then reignite the
appliance as per normal. Should the
appliance burn back again, close the gas
cylinder and call a registered LPG installer.
Do not use the appliance again until the
installer has conrmed that it is safe to
do so.
GAS-PRESSURE REGULATOR
This appliance requires an operating
pressure of 2,8 kpa. Only install a LPG low
pressure regulator that complies with the
SANS 1237 requirements.
GUARANTEE
After installation, please register your
product on the Dewhot website (www.
gasgeysers.co.za/product-registration)
You will need your invoice and Certicate
of Compliance (COC) to complete
the registration.
Important

Page 3 of 24
Dewhot | Gas geyser manual
Dewhot | Gas geyser manual
Only a registered gas
installer can install your
gas geyser and must
comply to SANS 10087-1
User
This appliance may only be installed by a
registered LPG installer.
Registered installers are issued with a card
that displays their registration number.
Insist on seeing this card and make a note
of their registration number.
When they have nished their installation
make sure the installer performs an
operational and safety brieng.
Before you sign o the installation, make
sure you also receive your COC
Installer
This appliance may only be installed by
a LPG Installer registered with the South
African Qualication and Certication
Committee (SAQCC). The appliance
must be installed in accordance with
the requirements of SANS 10087-l for
use with LPG and or any re department
regulations and/or local bylaws applicable
to the area.
If in doubt, check with the relevant
authority before continuing with the
installation. Once an installation is
complete you are required to brief, in full,
the operational and safety functions of
the appliance.

Page 4 of 24 Dewhot | Gas geyser manual
Description Outdoor Room Sealed
Model no OD20DH
Model Type D
Gas type LPG
Max gas pressure 2,8kpa
Hot water output 2.5-20L/min
Water pressure 0.25 - 5 BAR
Rated input 40kw
Water Flow 2,5 - 20L/min
Rated voltage 240V/60Hz
Rated Electrical Power 45W
IP Rate IPx4D
Max gas consumption 2.9 kg/h
Appliance size 575 x 365 x 150 mm
Unit weight 17.2 kg
Technical parameters
Temperature
Controler

Page 5 of 24
Dewhot | Gas geyser manual
Dewhot | Gas geyser manual
Lock ring
Water outlet
connector
Control unit support
Combustion valve
Water inlet connector
Water ow sensor
Transformer
Sensor pin
clamp
Chimney
gasket
Chimney
Temperature
Controler
Heat
exchager
Burner
Fan
Control
unit
Bottom
Panel
Power
cord
Bottom
support
Dispatcher
Front Panel
Sensor pin
Gas inlet connector
Parts Diagram

Page 6 of 24 Dewhot | Gas geyser manual
WATER FLOW SENSOR
This appliance has a water ow sensor that
will immediately ignite the burner when
detecting water ow.
FAN ASSISTED COMBUSTION
The motor and fan force oxygen into
the appliance to fuel the ame,
maximising eciency.
LOW WATER PRESSURE
START UP
The appliance will activate from a
water flow of 3lt/min. This indicates
that it is suitable for low water
pressure applications.
AUTOMATIC GAS ADJUSTMENT
The appliance will automatically adjust its
gas usage depending on the water usage,
using less gas when you use less water,
making the appliance more ecient.
DRY COMBUSTION PROTECTION
In the event of dry combustion (when the
gas burner comes on with out water ow),
the appliance will automatically shut down
OVER PRESSURISATION
PROTECTION
The appliance will automatically protect
itself by releasing pressure if the water
supply is over 10 Bar (this can be manually
set).
FLAME OUT SENSOR
This is designed to automatically cut o
the gas supply should the ame/ burner
unexpectedly extinguish or the sensor no
longer detects a ame.
REMOTE DIGITAL CONTROL
PANEL
Simplicity of adjusting the temperature of
the water by 1°C increments at the touch
of a button.
LONGER LASTING
Due to the seal around the entire cover of
the geyser it gets far less exposed to harsh
elements such as wind, rain and sea air. It is
better protected and thus longer lasting.
THERMAL FUSE
The thermal fuse wraps around the
heat exchanger and heats up in subzero
temperatures preventing the water from
freezing inside the pipes, causing them
to burst.
Functions & Features

Page 7 of 24
Dewhot | Gas geyser manual
Dewhot | Gas geyser manual
Safety instructions
FLAMMABLE MATERIALS
Flammable materials and liquids
(adhesives, solvents, paint thinners etc.)
are extremely dangerous.
DO NOT handle, use or store these
combustible materials near to the
gas geyser.
WATER TEMPERATURE
SETTING
Safety and energy savings need to be
considered when setting the water
temperature . Water temperatures above
52°C can cause severe burns.
Refer to page 16.
1. Households with small children, disabled
or elderly people need to set the
temperature to 49°C or lower
2. Maximum water temperature occurs
when the burner is on. To see the water
temperature look at the front control
panel of the gas geyser.
3. The Factory default water setting is 41°C
and this setting can be adjusted on the
control panel
4. The gas geyser has a heating range
between 35°C and 60°C.
TIME/TEMPERATURE EXPOSURE RESULTING IN BURNS
Hot water can create severe burns, we should rarely exceed the temperatures below
49°C More than 5 minutes
52°C 1.5 to 2 minutes
55°C +/- 30 seconds
57°C +/- 10 seconds
60°C less than 5 seconds
63°C less than 3 seconds
66°C +/- 1.5 to 2 seconds
69°C +/- 1 second

Page 8 of 24 Dewhot | Gas geyser manual
Safety instructions
NATURAL AND LP GAS
Both LP and natural gas are odoured to
help detect leaks.
Appliances using LP gas are dierent from
natural gas models. A natural gas gas
geyser can not function safely on LP gas
and vice versa.
Do not try to convert the gas geyser from
a natural gas to a LP gas appliance.
This could damage the appliance, cause
injuries or res. Never connect the
gas geyser to a fuel type that is not in
accordance with the appliance’s data table.
WHEN DETECTING A LEAK ON
YOUR INSTALLATION
LP gas is twice as heavy as air and may
accumulate in low lying areas and cavities.
Before opening the hot water tap to test
your gas geyser, check for gas leaks. Use a
soapy solution to check all gas ttings and
connections. Bubbles indicate a leak.
1. Do not attempt to nd the cause
yourself and turn o the gas supply.
2. Do not ignite any appliance.
3. Do not touch any electrical switch.
4. Evacuate the house immediately with
your family and pets.
5. Leave the doors open for ventilation and
contact the gas supplier, registered LP
Gas Installer or Fire Department.
6. Stay away from the house (or building)
until the service call has been made,
the leak is xed and the space has been
declared as safe.
7. Ask the installer to show you where the
gas shut-o valve is and how to use it.
8. Turn o the manual shut-o valve if
the gas geyser has been subjected to
overheating, re, ood, physical damage
or if the gas supply fails to shut o.
Gas detectors are highly recommended
and they must be installed in accordance
to the detector manufacturer’s regulations.

Page 9 of 24
Dewhot | Gas geyser manual
Dewhot | Gas geyser manual
Installation instructions
LOCATION
1. Long hot water pipes should be
insulated for water and
energy eciency.
2. The gas geyser and water pipes should
be protected from
freezing temperatures.
3. When installing a gas geyser a minimum
of 1 meter is required from any
venting system.
IMPORTANT
Do not solder the HOT or COLD water
connections. If solder connections are
used, solder the tting to the adapter
before tting the adapter to the water
connections. Any heat applied to the
water supply ttings will permanently
damage the internal components of the
gas geyser.
MOUNTING THE GAS GEYSER
Install the appliance in a place that allows
for easy access.
At least 8mm concrete plugs and screws
should be used to mount the gas geyser to
the wall. In the case of dry walling use dry
wall anchors.
The gas geyser requires a 13 amp plug
point
WATER SUPPLY
This appliance must only be used with
the following water supply requirements:
1. Clean, potable water free of corrosive
chemicals, sand, dirt, or other
contaminants.
2. With inlet water temperatures above
0°C, but not exceeding 49°C
3. Free of lime and scale deposits
DO NOT reverse the hot and cold water
connections, this will not allow the gas
geyser to function.

•
Page 10 of 24 Dewhot | Gas geyser manual
Safety instructions
WATER SUPPLY
CONNECTIONS
Plumbing should be carried out by
a qualied plumber. Use approved
plumbing materials only. The diameter
of the pipe lines should be a minimum
of 1/2”.
To conserve energy and to prevent
freezing, insulate both the cold and the
hot water supply lines. DO NOT cover the
drain valves.
WATER PRESSURE GUIDELINES
Operation of the gas geyser requires a
minimum water pressure of 14 psi (0,5
Bar) and a minimum water ow rate of
2.5 Litres/min.
1. For long pipe runs water pressure can
drops and additional water pressure
may be required.
2. When the water is supplied from a
water tank, the height of the tank,
the diameter of the pipes and their
relation to water pressure, should be
taken into consideration.
3. 5 meters above the shower head is
a minimum requirement if this is not
possible then gravity fed water is
not recommended
WATER SUPPLY
1. Sucient water pressure and ow rate
2. Make sure there are no water leaks
and that the water lter is clean.
3. Only compliant or specied materials
must be used
IMPORTANT
If the water ow is too slow, the gas
geyser will not ignite. Keep the shower
head clean from debris that reduces
ow rate.
To keep the water pressure balanced add
a 400-600kpa pressure regulating valve
on the cold water supply. Install a shuto
valve near the inlet of the gas geyser for
service and draining purposes.
Be sure to connect the water inlet and
the hot water outlet as shown on the
gas geyser. If reversed, the gas geyser
will not function.
Installation of unions or exible copper
connections are recommended on the
hot and cold water lines, so that the gas
geyser may easily be disconnected for
servicing.
Install a non-return between the gas
geyser and the water shuto valve.

•
Dewhot | Gas geyser manual Page 11 of 24
Dewhot | Gas geyser manual
HOT WATER OUTLET
Connections between the gas geyser
and the usage points should be as short
as possible.
DO NOT use lead or plastic pipe. To
save energy and reduce heat loss we
recommend insulating the water piping.
NOTE The ow rate of hot water may
vary when more than two taps or
xtures are being used at the same time.
GAS SUPPLY LEAK TESTING
1. The gas geyser and its gas connections
must be tested for leaks at the normal
operating pressures before using it.
2. Turn on the gas shut-o valve(s)
3. Use a soapy water solution to test for
leaks at all connections and ttings.
Bubbles indicate a gas leak that must
be xed.
4. Once the appliance is operating, the
factory connections also need to be
tested for leaks.
WARNING
Never use an open ame to test for gas
leaks as this could result in property
damage, personal injury and
or death.

Page 12 of 24 Dewhot | Gas geyser manual
GAS GEYSER LOCATION
1. Protected from freezing temperatures.
2. Clear 800mm of space from
combustible surfaces.
3. Sucient ventilation.
4. Air supply must be free of corrosive
elements and ammable vapours.
5. Sucient space to service the appliance.
6. Gas geyser must be securely mounted to
the wall.
7. The gas geyser must be installed at least
1400mm o the ground.
GAS SUPPLY
1. Gas type matches specication table.
2. Sucient pressure for the gas supply.
3. Gas line equipped with a shut o valve.
4. A soapy solution must be used to check
all connections and ttings for gas leaks.
5. The COC issued and signed.
ELECTRICAL CONNECTION
POWER CORD
Electrical connections and wiring must
comply with national standards.
• 220 V/50HZ is the electric power supply
requirement.
• The gas geyser comes with a 13 amp plug.
Only use a power outlet with a earthed
terminal.
• We recommend installing an electrical
leakage breaker.
• Keep the excess power supply cord on
the outside of the gas geyser.
WARNING
Before servicing the gas geyser, turn o
the electrical power to the gas geyser at
the plug or circuit breaker. Failure to do so
could result in electrocution.
Label all wires prior to disconnecting them
when servicing controls. Wiring errors can
cause malfunctions.

Page 13 of 24
Dewhot | Gas geyser manual
Dewhot | Gas geyser manual
Operation instructions
SAFETY PRECAUTIONS WHEN
OPERATING
Open the cold water valve to allow
water through the geyser. Close the
valve after the cold water is owing out
through the water outlet and you can
hear the geyser start to ignite.
1. Open the gas supply.
2. Open the water inlet valve and the
geyser will ignite immediately. Hot
water should ow out instantly. The
geyser may not ignite the rst time
due to an airlock, try turning it o and
then on until the geyser ignites.
3. Be aware of the water owing out of
the geyser as the temperature of the
water will be hot initially and may
burn you.
WARNING
1. Do not attempt to x or maintain this
gas geyser unless you are qualied to
do so.
2. The exhaust pipe must be installed to
extract the products of combustion to
the outside atmosphere.
3. Pay attention to the ame picture
from time to time. If there is abnormal
combustion such as a bright yellow
ame, close the gas valve right away
and contact the gas installer
for maintenance.
4. To avoid the pipes from freezing
during sub zero temperatures,
discharge the remaining water
after use.
5. The body of the gas geyser can
become very hot during operation,
so please do not touch any parts of
the gas geyser except for the control
panel or switches.
6. While using the gas geyser, please
pay attention to the initial water
temperature to prevent burning
yourself or others.
7. Inspect the gas pipes and exible hoses
regularly. If you nd joints that are not
tightly secured or if there are cracks,
you should stop using the appliance and
perform the necessary maintenance.
8. Turn o the gas shut-o valve if your
gas geyser has been subjected to over
heating, re, ood, physical damage
or if the gas supply fails to shut o.
9. Do not turn on the appliance unless
water and gas supplies are
fully opened.

Page 14 of 24 Dewhot | Gas geyser manual
10. Do not allow combustible materials
such as newspaper, rags or mops to
accumulate near the appliance.
11. Do not store or use petrol or other
ammable vapours and liquids, such
as adhesives or paint thinner, in the
vicinity of this or any other
gas appliance.
12. If such ammables must be used,
open doors and windows
for ventilation.
13. Appliances in the vicinity should be
shut o to avoid vapours igniting
from the gas burner.
14. Flammable vapours can be drawn by
air currents from surrounding areas to
the inlet of gas geyser.
ADJUSTING THE OVER
PRESSURISATION VALVE
When you have done a new installation
and have connected the water, then
you can use a small or medium at screw
driver to UNSCREW the grubscrew in the
hollow centre of the over-pressurisation
valve until the water leaks out.
Then screw it BACK IN 1.5 turns. This
will mean that the over-pressurisation
valve is set to the customers water
pressure supply and in the event of the
water in the pipes freezing the valve will
squirt out a small amount of water and
allow the water to freeze in the geyser
without causing damage.

Page 15 of 24
Dewhot | Gas geyser manual
Dewhot | Gas geyser manual
WATER TEMPERATURE
SETTINGS
The gas geyser temperature can be
regulated by adjusting the setting on the
front of the control panel.
Safety factors should be considered
so please read and follow the warnings
outlined on page 7.
Mixers can be used to adjust the
temperature at the water outlet.
When the burner is switched on,
maximum water temperatures are
reached. The water temperature is
determined by turning on a hot water
tap. Water temperature at the tap will
vary depending on the weather and
length of piping from the gas geyser.
This gas geyser contains an electronically
controlled thermostat. Factory defaults
range between 39°C and 70°C.
The control panel has been preset to 41°C.
To turn the control panel ON or OFF, hold
the POWER button for more than
3 seconds.
Set the temperature as required by
pressing the UP or down arrows on the
temperature button.
By pressing the UP or DOWN you
buttons will adjust the temperature point
by 1°C increments.
REMOTE CONTROL DISPLAY
(Displays water temperature
and Error Codes)
MODE
OUTPUT TEMP
SET TEMP
ERROR CODE
C

Page 16 of 24 Dewhot | Gas geyser manual
SETTING YOUR GAS GEYSER TO THE CORRECT
TEMPERATURE
• The gas geyser should be set to such a temperature that you should not have
to add too much cold water. If you set the temperature too high and have to
cool it down using the cold water, you have eectively wasted gas. Try set
the geyser so that you only have to open the hot water tap only.
• Start by setting the geyser to 41°C for pipe runs shorter than 3m. If your pipe
runs are from 3-5m try setting the geyser at 43°C and for pipe runs longer
than 5m try setting the geyser at 46°C. If you nd these temperatures are not
satisfactory then increase the temperature by 1-2°C at time until you feel the
water is hot enough.
• The hottest water temperature will be from the hot water tap closest to the
gas geyser.
• Always remember to test the water temperature with your hand before use
and remember that hotter water settings increase the risk of injury.
• The gas geyser is tted with a device that will shut o the gas supply to the
burner if the appliance exceeds normal operating temperatures.
• The appliance won’t operate with a water ow of less than 3 litres/minute.
If this occurs, increase the water ow.

Dewhot | Gas geyser manual
•
Page 17 of 24
Dewhot | Gas geyser manual
•
GENERAL
If your gas technician maintains your gas
geyser you should not have any issues
with it for years.
We recommend that you periodically
check the burner, relief valve, air intake
lter, water lter and venting system.
This needs to be done by a certied
installer. A maintenance program
is advisable.
Inspect the area around the gas
geyser to ensure that its in a safe
operating environment.
Make sure that the appliance has not
been damaged. If there are traces of
damage or denting contact your supplier
to check that the appliance is still
functioning properly.
Check for any abnormal sounds while
operating your appliance.
Check for gas/ water leaks.
The air and cold water supply lters should
be cleaned monthly.
NOTE
1. Before manually operating the relief
valve, make sure the gas geyser has not
been in operation, this is to avoid hot
water discharge from the relief valve.
2. If you don’t perform regular
maintenance the geyser can start
operating poorly which can cause
carbon monoxide poisoning, excessive
hot water temperatures or other
potentially hazardous conditions.
3. Make sure the electrical power to the
gas geyser is o to avoid electrocution
or damage to components.
4. Combustible materials, such as clothing,
cleaning materials, or ammable liquids,
etc. must not be placed against or next
to the gas geyser.
DO NOT
1. DO NOT continue to use the gas geyser
if you feel that there is something wrong
with it.
2. DO NOT allow children to operate or
handle the appliance.
After you have checked, maintained and/
or cleaned the appliance, make sure that it
is working properly by turning on the hot
water tap.

Page 18 of 24 Dewhot | Gas geyser manual
Cleaning
GENERAL
• Turn the appliance o and disconnect
the power supply before cleaning the
gas geyser.
• Clean the appliance and remote control
by using a damp soft cloth only. Gently
wipe the surfaces of the appliance and
any remaining moisture with a dry
soft cloth.
• Do not store household items near or on
top of the appliance
• Filters should be cleaned on a
monthly basis.
• DO NOT scrub the appliance with
a brush.
• Use only water, any chemicals can
damage the surface of the appliance.
• DO NOT remove any labels, including the
rating table when cleaning or servicing.
• DO NOT splash water on the remote
controls when cleaning.
•
•
CLEANING THE WATER
FILTER
• Turn the appliance o and disconnect
the power supply.
• Turn the water supply to the
appliance o.
• Unscrew the water lter and slide the
lter out.
• Do not tap the lter as it may damage it.
• Remove particles - use a soft brush and
rinse it with running water.
• Put the lter back and screw it in.
• Turn on rst the electrical power supply
and second the cold water supply.

Dewhot | Gas geyser manual Page 19 of 24
Dewhot | Gas geyser manual
CAUTION
Cleaning of the main burner should always
be performed by Registered LPG Installer.
A compressor can be used to clean
the burner.
VENT INSPECTION
The venting system should be checked
annually to ensure that all of the vent
sections are secure and air-tight.
DO NOT operate the appliance if vent
system shows signs of leaking.
Check to make sure that the AIR INTAKE
and the VENT TERMINAL has not been
blocked or contain debris.
BURNER INSPECTION
Visually check the main burners annually.
Use the sight glass to check the ame
picture, the ame should be a clean blue
ame only.
If a yellow ame occurs, the gas geyser
should be shut down and you should call a
qualied installer to assess the appliance.
Bubbles around a joint connection indicate
a seal leak.
VACATION AND EXTENDED
SHUT-DOWN
If the gas geyser is left for an extended
period of time, the power and gas to the
appliance should be turned o.
The gas geyser and piping should be
drained if they could be subjected to
freezing temperatures over this period.
After a long shut-down period, the gas
geyser needs to be serviced and checked.

Page 20 of 24 Dewhot | Gas geyser manual
Troubleshooting
Symptom Cause Solution
Not enough
or
no hot water
The water valve is not
completely open
Check the valve and make
sure its opened to its maximum.
The hot water tap is not
completely open
Make sure that the tap is
opened to its maximum.
(When the incoming water ow
below 2.5lt per min the main
burner shuts o).
The water pipes are frozen Let the pipes defrost
Appliance is not “ON” Turn the appliance “ON” by the
button on the remote control.
The temperature may be
set too low
Increase the temperature
setting on the controller.
Mixer malfunction Check and replace the mixer.
Error code displayed on
remote control panel
See Error Codes on page 23
and contact an installer.
Fan continues to
rotate after hot
water faucet
is closed.
This function is to remove
any burnt or unburned
gases from the
burning chamber.
Normal operation. There is no
need to call for service.