Smithco ADMP 40 G Manual

INSTALLATION INSTRUCTIONS
AND USER'S MANUAL
UNITED KINGDOM
WATER HEATERS
MODELS ADMP 40 G
ADMP 50 G
ADMP 60 G
ADMP 80 G
ADMP 90 G
ADMP 115 G

2
FOREWORD
Before attempting to install this water heater please read the installation instructions. Read the user’s manual before first
igniting the heater. Failure to follow these instructions meticulously could lead to risk of an explosion and/or fire and can
cause material damage and/or physical injuries.
An accredited installer must install the heater and commission it for the first time. The type of gas and the values are pre-
set (ex works) and are given on the model plate. The heater may only be installed in an area of which the available
clearances comply with the required ventilation regulations.
The ADMP models are fitted with a permanent pilot light.
A.O.SMITHCANNOTACCEPTANYRESPONSIBILITYFORGUARANTEE,SERVICEAND/ORPRODUCTLIABILITYINTHE
EVENTOFUNAUTHORISEDCHANGES, PRODUCT MODIFICATIONS OR REPAIRS.

3
CONTENTS PAGE
PILOT-LIGHTHEATERS(modellenADMP40t/m115)
1GENERAL
1.1 Description of the heater ................................................................................................................ 4
1.2 Technical safety equipment............................................................................................................ 5
1.2.1 Gas control block ............................................................................................................................ 5
1.2.2 Control box ...................................................................................................................................... 5
1.2.3 Thermal reflux safeguard (TRS) .....................................................................................................5
1.3 Technical description...................................................................................................................... 6
1.3.1 Dimensions .................................................................................................................................... 6
1.3.2 Technical data................................................................................................................................. 8
2 FORTHEINSTALLER
2.1 Installation instructions.................................................................................................................10
2.1.1 Installation.....................................................................................................................................10
2.1.2 Water connection ..........................................................................................................................10
2.1.3 Gas connection .............................................................................................................................12
2.1.4 Flue system...................................................................................................................................12
2.1.5 Flue-gas discharge.......................................................................................................................12
2.1.6 Thermal reflux safeguard (TRS) ...................................................................................................13
2.1.4 Electrical connection.....................................................................................................................13
2.2 Commissioning............................................................................................................................14
2.2.1 Filling the heater ...........................................................................................................................14
2.2.2 Commissioning ADMP models....................................................................................................14
2.2.3 Setting the pilot light......................................................................................................................14
2.3 Shutting down ...............................................................................................................................14
2.4 Operation/temperature control .....................................................................................................14
2.5 Setting the nominal loads.............................................................................................................15
2.6 Conversion to another gas ...........................................................................................................15
2.7 Maintenance..................................................................................................................................17
2.8 Anode ............................................................................................................................................17
2.9 Deliming........................................................................................................................................17
2.10 Condensation ...............................................................................................................................17
2.11 Spare parts ...................................................................................................................................17
3 FORTHEUSER
3.1 Instructions for use .......................................................................................................................18
3.1.1 Warning .........................................................................................................................................18
3.1.2 Filling the heater ...........................................................................................................................18
3.1.3 Commissioning ADMP models....................................................................................................18
3.2 Operation ......................................................................................................................................18
3.3 Shutting down ...............................................................................................................................18
3.4 Maintenace ....................................................................................................................................18
4 WHATTODOINCASEOFAFAILURE
4.1 General .........................................................................................................................................19
4.1.1 Overheat thermostat .....................................................................................................................19
4.1.2 Thermal Reflux Safeguard (TRS) .................................................................................................19
4.1.3 Wrong hot water temperature .......................................................................................................19
4.1.4 Water temperature too high ..........................................................................................................19
4.2 Fault overview................................................................................................................................20
5WARRANTY
5.1 Garantee in general ......................................................................................................................21
5.2 Garantee of the tank...................................................................................................................... 21
5.3 Conditions for installation and use ..............................................................................................21
5.4 Exclusions.....................................................................................................................................21
5.5 Range of the quarantee ................................................................................................................21
5.6 Claims...........................................................................................................................................21
5.7 No other quarantee or warranty either expressed or implied is made on behalf
of A.O.SMITHWATERPRODUCTSCOMPANY ...........................................................................21
Appendix1 Electrical scheme ADMP-models.................................................................................................22

4
Diagram 1- Cross-section ADMP-models
1 Draught diverter
2 High-limit and overheat
thermostat sensors
3 Hot-water outlet
4 Thermostat sensor
5 Control box
6 Cold-water inlet
7 Drain cock
8 Thermocouple
9 Pilot burner
10 Gas control block
11 Flue-pipe connection
12 Covering plate for flue-damper
assembly
13 Support for draught diverter
14 T&P connection (temperature
and pressure valve)
15 Anode
16 Flue tubes
17 Flue baffles
18 Insulation
19 Bar burners
20 Radiation shield/condensate
tray
PILOT LIGHT HEATERS (MODELS ADMP)
1. GENERAL
1.1 Description of heater
Construction methods and equipment of the heaters are
in accordance with the European standards for gasfired
hot water heaters for sanitary use (EN 89). The heaters
are therefore comply with the European Guidelines for
Gas Heaters and are therefore permitted to carry the CE
hallmark. These are open flued heaters without
mechanical ventilator, with a Thermal Reflux Safeguard
(TRS) (heater category B11BS ). The heaters are suitable
for use with a working pressure of up to 8 bar.
The cylindrical tank is made from sheet steel containing
a number of vertically placed flue tubes. For protection
against corrosion, the inside of the tank is enamelled.
The tank is also fitted with a number if magnesium
anodes for extra protection against corrosion. A thick PU
insulating layer between the tank and the steel jacket
helps to reduce unnecessary heat loss.
When the heater is completely filled with water, it is
under continual mains water pressure. When hot water
is drained from the heater, cold water immediately
enters the heater. For effective heat transfer flue baffles
have been included in the flue tubes. Heat from the flue-
gases is transferred to the water by means of radiation
and convection. The flue-gases are guided to the
chimney via a rotateable and removable draught diverter.
Flue-gases are discharged by thermal draught.
The atmospheric burner consists of a number of bar
burners. One injector is screwed into the manifold for
each bar burner. The function of the injectors in the inlet
venturi ensures a good mixture of gas and primary air.
Secondary air is drawn in between the bar burners. The
permanent piliot light ensures that the burner ignites as
soon as there is a demand for heat.
A radiation shield is fitted beneath the burner which also
serves to collect any condensate (see diagram 1)

5
1.2 TECHNICALSAFETYEQUIPMENT
1.2.1. Gas control block
the heaters are equipped with a gas control block which
regulates the flow of gas to the burner. The gas control
block is equipped with a safety valve, gas control valve,
pilot light pressure control and burner control (on a
standard natural gas setting). The safety valve is
controlled by the millivoltage generated when the
thermocouple is heated by the permanent pilot. To
ensure improved ignition the gas control valve opening
mechanism is fitted with a delay (softlite).
1.2.2. Controlbox
Temperature control for the water heater is housed in
the control box. For safety purposes, heaters are always
filled with three thermostats: a control thermostat, a
high-limit thermostat and an overheat thermostat. The
desired water temperature is set with the control
thermostat. The overheat thermostat prevents the water
reaching too high a temperature.
Diagram 2- Control box ADMP-models
Should both control and high-limit thermostats
malfunction, the overheat thermostat will automatically
shut down the heater. The overheat thermostat breaks
the thermocouple circuit, which closes the safety valve,
cutting of the supply of gas to the pilot burner which
extinguishes the pilot light.
The control thermostat can be set at settings 1-4
(approx. 40ºC to 73ºC). the switch temperature of the
high-limit thermostat is 84ºC; the overheat thermostat
cuts in at 93ºC. The sensor for the control thermostat is
located at the level of the control box; the sensors for the
high-limit and overheat thermostats are located near the
top of the heater.
The control box is fitted with an ON/OFF switch (I/O).
At setting I, the gas control block is controlled on the
basis of heat demand from the control thermostat. At
setting O the heater is switched off.
1.2.3. Thermal Reflux Safeguard
The heater is equipped with a Thermal Reflux Safeguard
(TRS), which consists of a temperature sensor and
thermostat fitted to the draught diverter. The function of
the TRS is to switch off the heater if flue gases pass
through the draught diverter and enter the area in which
the heater is installed instead of being expelled via the
chimney.

6
1.3 TECHNICALDESCRIPTION
1.3.1 Dimensions (see diagram 3)
The heaters must be connected to a flue with a
minimum of the prescribed diameter (see size G).
Connection to a pipe of a larger diameter by means of a
coupling is permitted.
Size
A
B
D
E
F
G
H
J
K
L
M
N
P
R
S
1
2
3
4
5
6
ADMP40
1900
1760
710
800
1100
150
660
1840
205
400
565
1605
730
500
1550
ADMP50
2100
1960
710
800
1100
150
660
2040
205
400
565
1810
730
515
1760
ADMP60
1900
1760
710
800
1100
180
660
1840
205
400
565
1605
730
500
1550
ADMP80
2100
1960
710
800
1100
180
660
2040
205
400
565
1810
730
515
1760
ADMP90
2000
1795
710
800
1105
225
675
1935
205
400
575
1640
740
525
1595
ADMP 115
2085
1870
710
800
1105
225
675
2010
205
405
650
1715
825
600
1660
Cold water inlet
Hot water outlet
Gas control block
Drain cock
T&P-connection (temperature and pressure valve)
Covering plate for inspection hatches
All measurements are given in millimetres (rounded off to the nearest 5 mm).

7
Diagramm 3 - dimensions ADMP

8
DESCRIPTION Unit ADMP 40 ADMP 50 ADMP 60 ADMP 80 ADMP 90 ADMP 115
NATURAL GAS DATA G20-20mbar
Nominal input (lower value) kW 38.0 50.9 59.8 74.3 88.5 114.0
Nominaloutput kW 32.3 42.8 50.2 62.4 74.395.8
Inlet pressure (G20) mbar 20 20 20 20 20 20
Burner pressure (G20) mbar 8.5 8.5 8.5 8.5 8.5 8.5
Gas consumption * (G20) m3/h 4.0 5.4 6.3 7.9 9.4 12.1
Diameter main injector (G20) mm. 3.20 3.20 3.10 2.95 3.20 3.20
Diameter pilot light injector (G20) mm 0.56/0.41 0.56/0.41 0.56/0.41 0.56/0.41 0.56/0.41 0.56/0.41
Heating time ∆T = 45K min. 30 26 19 17 12 8
BUTANE DATA G30 - 30 mbar
Nominal input (lower value) kW 38.4 51.0 62.9 74.5 88.7 114.0
Inlet pressure (G30) mbar 30 30 30 30 30 30
Burner pressure (G30) mbar 30 30 30 30 30 30
Gas consumption * (G30) kg/h 3.0 4.0 5.0 5.9 7.0 9.0
Diameter main injector (G30) mm. 1.70 1.70 1.70 1.50 1.70 1.70
Diameter pilot light injector (G30) mm. 0.25 0.25 0.25 0.25 0.25 0.25
Heating time ∆T = 45K min. - - -- --
PROPANE DATA G31 - 37 mbar
Nominal input (lower value) kW 35.3 47.0 58.2 71.5 82.4 104.0
Inlet pressure (G31) mbar 37 37 37 37 37 37
Burner pressure (G31) mbar 37 37 37 37 37 37
Gas consumption * (G31) kg/h 2.7 3.7 4.5 5.66.4 8.1
Diameter main injector (G31) mm. 1.70 1.70 1.70 1.50 1.70 1.70
Diameter pilot light injector (G31) mm. 0.25 0.25 0.25 0.25 0.25 0.25
Heating time ∆T = 45K min. - - -- --
1.3.2. Technical data
Heater categorie II2H3+
* Gas consumption at 1013,25 mbar and 15°C

9
GENERAL
Storage capacity litre 309 357 298 355 278 253
Numbers of bar burners - 3 4 5 7 7 9
Number of anodes - 2 2 2 3 3 4
Number of flue tubes - 5 6 7 9 12 16
Water connections - Rp 1½ Rp 1½ Rp 1½ Rp 1½ Rp 1½ Rp 1½
Gas connection - Rp ¾ Rp ¾ Rp ¾ Rp ¾ Rp ¾ Rp ¾
Drain cock - ¾"NPT ¾"NPT ¾”NPT ¾"NPT ¾"NPT ¾” NPT
Anode - ¾"NPT ¾"NPT ¾”NPT ¾"NPT ¾"NPT ¾”NPT
T&P - plug connection - 1"NPT 1"NPT 1"NPT 1"NPT 1"NPT 1"NPT
Maximum working pressure bar 8 8 8 8 8 8
Weight (empty) kg 195 221 209 238 244 270

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2. FOR THE INSTALLER
2.1. INSTALLATIONINSTRUCTIONS
This water heater must be fitted in a location which will
permit the provision of an approved flue system and
adequate ventilation.
The water heater must stand on a level surface resistant
to heat and with sufficient strength to support the weight
of the unit when full of water.
This water heater must not be installed in a bathroom,
bedroom or in a cupboard opening on to such rooms.
This water heater must not be installed in any area
where flammable materials are used or stored.
Insufficient ventilation may give rise to a risk of fire,
explosion or suffocation. If in doubt consult the national
and local regulations governing the installation of gas
appliances or your local British gas service department.
2.1.1 Installation
These water heaters must be installed by a qualified
competent installer, in accordance with the following
standards and regulations.
Gas safety (installation and use) regulations 1944.
BS 5440 part 1 1990
part 2 1989
Installation should be carried out in accordance with all
local authority and building regulations, local water
authority and fire regulations and the following British
standards: British Gas Publication UP1 and UP2.
BS 5482 part 1 1979
part 2 1979
part 3 1979
BS 6644
BS 6700
BS 6798
Some chemicals produce vapours which can cause
rapid failure of thermocouples, burners and storage
tanks if they ware drawn into the combustion air supply.
Therefore if this water heater will be used to supply hot
water to:
- hairdressers
- dry cleaners
- industrial degreasing processes
or any other area where compounds containing
halogens are used and stored, care should be taken
that all primary and secondary air is drawn from outside
atmosphere free of such contaminents.
For further advise contact A.O.Smith.
2.1.2 Water connections
A.O.Smith water heaters are suitable for connection to
vented, unvented and pumped pressurised systems. In
each case appropriate valves and fittings should be
used to ensure the system complies with the
requirements of the water by laws, and appropriate
building regulations.
When fitting it is essential the rules of ‘good practice’ are
applied at all stages of installation.
Vented systems
If the water heater is to be connected to a cold feed tank
of cistern the hot water supply pipe must include an
open vent which discharges over the cold feed cistern.
The cold feed cistern must have an actual capacity of
greater volume than the hourly recovery rate of the water
heater(s) which it supplies. The minimum actual
capacity is 50 gallons or 227 litres. See diagram 4.
Diagram 4 – Typical UK vented system
1 Gas cock
2 Stopvalve
3 Three way vent valve
4 T&Pvlave
5 Non-return valve
6 Circulation pump
7 Drain valve
A Gas Supply
B Hot Water
C Cold Water
D Overflow
E Return Circulation

11
Unvented
To install an A.O.Smith water heater on an unvented cold
water supply system a kit of valves and fittings listed by
the water research centre and complying with part G3 of
the current building regulations and BS 7206 should be
used. Installation should be carried out generally as
shown on diagram 5.
Diagram 5 – Connection diagram (unvented system)
1 Gas cock
2 Stopvalve
3 Expansion vessel
4 T&Pvalve
5 Non-return valve
6 Circulation pump
7 Drain valve
8 Pressure limiting
valve
9 Expansion valve
A Gas Supply
B Hot Water
C Cold Water
D Hot Water Supply
E Return Circulation
A.O.Smith water heaters are tested to a maximum
pressure of 12 bar and a maximum working pressure of
8 bar.
Dead legs on a hot water installation are undesirable.
Where possible they should be avoided. Where the
inclusion on the system of a dead leg is unavoidable the
following restrictions should be applied:
- for pipes not exceeding 19 mm. Inside diameter;
maximum length of dead leg permitted 12.0 metres;
- for pipes exceeding 19 mm. But not exceeding 25
mm. Inside diameter; maximum length of dead leg
7.5 metres;
- for pipes with an inside diameter exceeding 25 mm.
maximum dead leg 3.0. metres.
Depending on the length and insulation of the water
piping and the water demand frequency, it may be
necessary to install a circulation system on the drain
cock. The return pipe of the circulation piping can be
fitted on the top of the drain cock after the sealing plug
has been removed (see diagram 6).
Diagram 6 – Connection point for the return piping.

12
Depending on the water demand pattern (e.g., small
amounts frequently), it may be necessary to circulate the
water in the heater to prevent temperature stratification.
Therefore, we recommend that a circulation system is
installed in the event of such demand patterns (see
diagram 7)
1 Pump (type: Grundfos UP 20-15 N 150 or equivalent)
2 Non-return valve
3 Gatevalve
4 Drain valve
A Cold water
B Hot water
C Return circulation
D Gas supply
2.1.3 Gas connection
The gas supply to this appliance must be installed in
accordance with BS 6891 (1988) and British Gas
Publications Up1 and UP2.
Fit the ¾” gas supply cock supplied with this unit
immediately before the gas control block. No heat or
soldered joints should be applied in the vicinity of the
gas control block, as they could cause damage to the
control.
All connections and joints should be tested for gas
soundness with a suitable leak detector (do not use a
naked flame)
NB. When operating this unit on LPG a suitable gas
supply cock should be used)
2.1.4 Flue system
The water heater should be fitted with a flue system
connected to the draught diverter. The flue pipe should
rise for at least 50 cm. vertically before the inclusion of
any bends. If a horizontal run of flue is required this
should be kept to a minimum length possible and
incorporate a rise of 6 cm. per metre of run. A split clip or
flange should be provided in the flue close to the
draught diverter for ease of servicing.
All flue materials should be corrosion resistant i.e.
stainless steel or galvanised and must include a tested
and approved terminal to BS 5440 part I.
Diagram 7 – Connection diagram including
destratification circulation system
2.1.5 Flue-gas discharge
The horizontal draught diverter supplied separately must
be used to connect the heater to the chimney
The draught diverter can be turned to ensure that the
distance to the discharge duct is as short as possible.
Once the position has been determined, drill two small
holes (3.2 mm.) to fix the support bracket (fitted to the
pallet) below the draught diverter (see diagram 8).
Diagram 8 – Position draught diverter

13
2.1.7 Electrical connection
All electrical connections must be carried out in
accordance with IEE regulations by an accredited
electrical installation company. The control box of the
ADMP models must be connected to the mains by
means of a permanent electrical connection. A main
switch must be fitted in the phase between the
permanent connection and the heater. The feeder cable
must have cores of at least 3 x 1.0 mm². Always check
with a voltage tester if the phase and the zero have been
connected correctly in the control box. The electricity
supply must comply with the requirements below:
Electricity Frequency Electrically
supply fuse to a
minimumof
220/240 V AC 50 Hz 16 A
(-15% / +10%) (+/- 2%)
The electricity diagram can be found in the appendix
Then drill two small holes in the top lid of the heater and
fix the draught diverter with the two self-tapping screws
provided (see diagram 9).
The stainless steel discharge pipe must have at least
the same diameter as the connection on the draught
diverter. The discharge pipe must start from the draught
diverter with a vertical section of at least 0.5 m. No
modifications may be made to the draught diverter
discharge or any covers attached to it.
Diagram 9 – Fitting the draught diverter
2.1.6 Thermal Reflux Safeguard (TRS)
The temperature sensor and the thermostat of the
Thermal Reflux Safeguard (TRS) must be mounted on
the draught diverter in the correct way and in the proper
position. Do this as follows:
1 Remove the TRS from the packaging.
2 Insert the temperature sensor from the outside
through the hole in the draught diverter.
3 Mount the thermostat onto the draught diverter with
the self-tapping screws provided (see diagram 10)
4 Mount the temperature sensor at the correct position
on the lower edge of the draught diverter by means of
the clamps and the M4 screws provided (see
diagram 10)
5 Fix the TRS cabling on the draught diverter with two
clamps (see diagram 9).
6 Lead the TRS cabling to the cable duct on the heater.
Fix the cabling to the heater with the remaining
clamps.
Diagram 10 – Mounting the TRS on the draught diverter

14
2.2 COMMISSIONING
2.2.1 Filling the heater
1 Fit drain cock and check that it is closed
2 Open the cold-water tap to the heater and all hot-
water outlets in order to remove all air from the
system. The heater has been filled when cold water
runs out at all outlets.
3 Close all the hot-water taps. The heater is now under
mains pressure
2.2.2 Commissioning
ADMPmodels:
1 Switch the electrical supply to the control box off by
switching off the main switch
2 Check that the heater is filled with water and that the
gas supply to the heater is on.
3 Remove all air from the gas supply by opening the
pressure nipple at the inlet side of the gas control
block. Close the pressure nipple as soon as all the
air has been removed from the gas supply
4 Turn the temperature dial anti-clockwise as far as it
can go
5 Press the white control button on the gas control
block and keep it pressed in while pressing the
piezo ignition a number of times until the pilot light is
lit.
6 Press the white control button for about 30 seconds.
When it is released the pilot light must remain lit. If it
does not wait 5 MINUTES before repeating the
ignition procedure.
7 Switch on the electrical supply by switching on the
main switch.
8 Set the I/O button to I. The control light on the switch
will light up.
9 Turn the temperature control dial to the desired
position, position 3 (approx. 60ºC) is recommended.
The burner ignites; the heater will now operate
automatically
10 Check the inlet pressure and burner pressure on the
manometer which can be connected to the pressure-
test nipple. The heater must not be operational while
the manometer is being connected!
2.2.3 Setting the pilot light
The pilot light has been set at the factory
2.3 SHUTTINGDOWN
ADMPmodels:
For brief periods:
1. Turn the temperature control dial anti-clockwise as
far as it will go and set the I/O switch on O. The pilot
light will continue to burn.
For longer periods:
1. Press the red button on the gas control block (pilot
light goes out)
2. Close the gas tap in the feeder piping
3. Close the water inlet tap
4. Switch off the electricity supply
5. Empty the heater in case of imminent frost
2.4 OPERATION/TEMPERATURECONTROL
The temperature is regulated by the control box. The
control thermostat in the control box automatically
switches the gas supply to the burner via the gas control
box. This means that the gas supply to the burner is
opened when the water temperature reduces and that it
is closed when the set temperature is reached. The
temperature is indicated by the position of the
temperature dial:
Position 1 = approx. 40ºC
Position 2 = approx. 50ºC
Position 3 = approx. 60ºC
Position 4 = approx. 70ºC
Calcium deposition increases at high temperatures. In
addition, standby losses are greater when the
temperature is high. Therefore, we recommend that the
control thermostat is set at 60ºC. For safety reasons, the
heater is equipped with a high-limit and overheat
thermostat. The pilot light continues to burn when the
high-limit thermostat is activated. The pilot light is
extinguished when the overheat thermostat is activated.
Diagram 11 - operating the gas control block

15
2.5 SETTINGTHENOMINALLOADS
The nominal loads have been set at the correct values at
thefactory.
Dangerous situations can develop if the instructions
below are not followed meticulously. Setting the nominal
load is only necessary during burner pressure control. If
the burner pressure or loads must be checked, the
procedure below must be followed:
1 Shut down the heater by pressing the red button on
the gas control block.
2 Connect a U-pipe manometer to the pressure test
nipple to measure the burner pressure on the
manifold.
3 Activate the heater and allow the burner to ignite.
4 Check the burner pressure. If necessary, reset it by
means of the burner pressure adjusting screw (see
diagram 12). Turning it anti-clockwise as far as it will
go, reduces burner pressure. Turning it clockwise,
increases burner pressure.
5 Shut down the heater, remove the U-pipe manometer
and close the pressure test nipple.
6 Restart the heater.
2.6 CONVERSIONTOANOTHERGAS
Attention: mount a gas cock which is suitable
for the gas supply to be used.
If the heater has to function on a gas category (LP gas or
natural gas) other than the gas set as standard (ex
works), the heater must be converted to the applicable
gas category with the conversion kits provided.
Diagram 12 – Setting the nominal loads/burner
pressure
Only an accredited installer may convert the heater. Al
the injectors of the bar burners and the pilot light must
be replaced.
All natural gas units require a burner pressure regulator,
but LP gas units do not. The burner pressure regulator,
but LP gas units do not. The burner pressure regulator
of the gas control block (if present) must be dismantled
when converting the heater for the use of LP gas. The
burner pressure regulator must be mounted on the gas
control block when converting to natural gas. The table
below shows which injectors must be mounted for the
gas in question.
The following procedure should then be followed
meticulously:
1 Shut the heater down. Close the main gas tap in the
gas supply and switch off the electricity supply at the
main switch.
2 Dismantle the bar burners including the bar burners
including the bar burner on which the pilot light is
mounted. To do this, dismantle the pilot light gas
pipe and the thermocouple connection of the gas
control block.
3 Replace the injectors in the manifold and the pilot
burner with the injectors from the appropriate
conversion kit. Use the table on page 22 to check
that the diameter of the injectors is correct
4 Remount the bar burners.
5 Reconnect the pilot light gas pipe and the
thermocouple connections to the gas control block.
6Converting from natural gas to LP gas:
- Dismantle the burner pressure control on the gas
control block. Remove the burner pressure
control and replace it with the flat covering plate
with sealing packing in the conversion kit for LP
gas (see diagram 13).
- Replace the gas cock by one, which is suitable
for LP gas installations.
- Open the main gas tap.
- Check the burner pressure
Diagram 13 – Dismantling the burner pressure control

16
Converting from LP gas to natural gas:
- Replace the gas cock by one which is suitable for
natural gas installations.
- Mount the burner pressure control on the gas
control block. To do this, remove the flat covering
plate on the gas control block and replace it with
the burner pressure control in the conversion kit
for natural gas (see diagram 14)
- Open the main gas tap
- Set the correct burner pressure according to the
table above.
7 Check the operation of the heater
8 Fix the conversion sticker in the conversion kit to the
heater (below the type plate) so that it is clear on
which gas category the heater operates.
Diagram 14 – Mounting the burner pressure control
Unit ADMP40 ADMP50 ADMP 60
G20 G30 G31 G20 G30 G31 G20 G30 G31
Inlet pressure mbar 20 30 37 20 30 37 20 30 37
Burner pressure mbar 8.5 30 37 8.5 30 37 8.5 30 37
Diameter injectors mm 3.20 1.70 1.70 3.20 1.70 1.70 3.10 1.70 1.70
Diameter pilot mm 0.56/ 0.25 0.25 0.56/ 0.25 0.25 0.56/ 0.25 0.25
light injectors 0.41 0.41 0.41
Unit ADMP 80 ADMP 90 ADMP 115
G20 G30 G31 G20 G30 G31 G20 G30 G31
Inlet pressure mbar 20 30 37 20 30 37 20 30 37
Burner pressure mbar 8.5 30 37 8.5 30 37 8.5 30 37
Diameter injectors mm 2.95 1.50 1.50 3.20 1.70 1.70 3.201.70 1.70
Diameter pilot mm 0.56/ 0.25 0.25 0.56/ 0.25 0.25 0.56/ 0.25 0.25
light injectors 0.41 0.41 0.41
G20 = natural gas
G30 = butane
G31 = propane

17
2.7 MAINTENANCE
The heater must be checked and cleaned regularly (at
least once a year) by an accredited installer, so that
proper operation is guaranteed. The bar burners, the pilot
burner and the control and safety valves must also be
checked.
2.8 ANODE
The life of the anode is determined by the quality and
quantity of the water flowing trough the heater. Therefore,
we recommend that the anode is checked regularly –
preferable simultaneously with an internal inspection of
the enamelled tank. In order to determine the frequency
with which the anodes must be replaced, the water side
of the boiler must be checked three months after
installation. The anodes must be replaced if more than
60% has dissolved at any point on their length.
To inspect the tank:
1 Close the cold-water inlet tap
2 Empty the heater completely by opening the drain
cock.
3 Remove the covering plates from the inspection
hatches on the heater’s outer jacket
4 Open the handholes and inspect the anodes.
Replace the cardbord gaskets, rubber o-rings,
washers and bolts, to ensure the handholes are
watertight if they have been open (see figure 15).
Fasten the bolts with a maximum torque of 50 Nm.
Diagram 16 – Replacing the anodes
5 Assemble everything in reverse order
6 Fill the heater
2.9 DELIMING
Calcium deposition depends on the type of water and the
demand. In addition, calcium deposition increases at
high water temperatures. A temperature setting of 60ºC is
recommended, which will keep calcium deposition to a
minimum.
Inspection hatches are located on the right and left sides
for inspecting and deliming the tank. The inspection
hatches can be reached via the covering plates on the
outer jacket.
Empty the heater before opening the inspection hatches.
Deliming must be carried out with a suitable substance.
Consult the supplier or installer. Replace the cardbord
gaskets, rubber o-rings, washers and bolts, to ensure the
handholes are watertight if they have been open (see
figure 15). Fasten the bolts with a maximum torque of 50
Nm.
2.10 CONDENSATION
When the heater is filled with cold water or the hot-water
consumption is very high, the flue-gases will condense
on the cold surfaces of the combustion chamber and the
flue-gases discharge pipes. The drops of water will fall
on the burner and cause a hissing sound. This is normal
and will stop as soon as the operating temperature has
been reached.
2.11 SPAREPARTS
It is important to mention the heater, type, model and full
serial number when ordering spare parts. The spare
parts can be determined according to these numbers.
Diagram 15 – Closing the inspection hatches
To inspect the anodes:
1 Dismantle the draught diverter
2 Unscrew the fastening screws on the lid edge.
3 Remove the lid. The mounting brackets the anodes
are now visible (see diagram 16)
4 Unscrew the anodes with the appropriate tools and
replace with new anodes if required.
Attention: the anodes must make contact with the tank
(metal on metal). If the tank and the
anodes are separated electrically (as a result of the
sealing material used), the anode cannot function.
This could have a negative effect on the operating life
of the tank.
IMD 0235

18
3 FOR THE USER
3.1 INSTRUCTIONSFORUSE
3.1.1 Warning:
An accredited installer must install and commission the
heater for the first time
3.1.2 Filling the heater
1. Fit drain cock and check that it is closed
2. Open the cold-water tap to the heater and all hot-
water outlets in order to remove all air from the
system. The heater has been filled when cold water
runs out at all outlets.
3. Close all the hot-water taps. The heater is now under
mains pressure. The relief valve may not release any
water at this pressure, which can be read on the
manometer.
3.2 COMMISSIONING
ADMPMODELS:
1. Switch the electricity supply to the control box off by
switching off the main switch.
2. Check that the heater is filled with water and that the
gas supply heater is on.
3. Tum the temperature dial anti-clockwise as far as it
can go.
4. Press the white control button on the gas control
block and keep it pressed in while pressing the
piezo ignition a number of times until the pilot light is
lit. The pilot light can be seen through the inspection
window above the burner assembly.
5. Press the white control button for about 30 seconds.
When it is released the pilot light must remain lit. If it
does not wait 5 minutes before repeating the ignition
procedure.
6. Switch on the electricity supply by switching on the
main switch.
7. Set the 1/O button to I. The control light on the switch
will light up.
8. Turn the temperature control dial to the desired
position, position 3 (approx. 60ºC) is recommended.
The burner ignites; the heater will now operate
automatically.
3.2 OPERATION
The temperature is regulated by the control box. The
control thermostat in the control box automatically
switches the gas supply to the burner via the gas control
box. This means that the gas supply to the burner is
opened when the water temperature reduces and that it
is closed when the set temperature is reached. The
temperature is indicated by the position of the
temperature dial:
Position 1 = approx. 40ºC
Position 2 = approx. 50ºC
Position 3 = approx. 60ºC
Position 4 = approx. 70ºC
Calcium deposition increases at high temperatures. In
addition, standby losses are greater when the
temperature is high. Therefore, we recommend that the
control thermostat is set at 60ºC. For safety reasons, the
heater is equipped with a high-limit and overheat
thermostat. The pilot light continues to burn when the
high-limit thermostat is activated. The pilot light is
extinguished when the overheat thermostat is activated.
The pilot light must be relit before the heater can be
operational once again.
3.3. SHUTTINGDOWN
ADMPmodels:
For brief periods:
1. Turn the temperature control dial anti-clockwise as
far as it will go and set the I/O switch on O. The pilot
light will continue to burn.
For longer periods:
1. Press the red button on the gas control block (pilot
light goes out)
2. Close the gas tap in the feeder piping
3. Close the water inlet tap
4. Switch off the electricity supply
5. Empty the heater in case of imminent frost
3.4 MAINTENANCE
Maintenance should be carried out at least once per
year in accordance with the recommendations of
A.O.Smith. Failure to carry out adequate maintenance
may render the warranty void. We recommend that you
take out a maintenance contract with your installer.

19
4 WHAT TO DO IN CASE OF A FAILURE
4.1 GENERAL
If faults occur, check the following points:
4.1.1 Overheat thermostat
The heaters are equipped with an overheat thermostat,
which shuts off the gas supply if the water temperature
becomes too high. The overheat thermostat remains
engaged until the water temperature falls below the
overheat thermostat shut-off point. The heater must then
be restarted, as the pilot light is also extinguished for
reasons of safety. Remember to set a lower water
temperature on the control thermostat.
4.1.2. Thermal Reflux Safeguard (TRS)
If the TRS shuts the heater down, the heater can be
restarted using the following method:
1. Allow the temperature sensor to cool down until the
temperature falls below the sensor switching
temperature.
2. Operate the RESET button on the TRS by pressing
the small black catch on the thermostat until you feel
a slight click (see diagram 17)
3. The heater restarts and can be operated again.
If the TRS repeatedly shuts down the heater, this
indicates a flue-gas discharge problem. The only
solution is to track down the cause of these problems
(e.g., blocked chimney) and rectify it.
4.1.3. Wrong hot water temperature
1 Check the control thermostat setting.
2 Check that the pilot light is lit. If necessary, relight the
pilot light.
3 Check that there are no leaks or if any taps are open.
4 Check the water temperature just out of the heater to
ensure that low water temperature is not being
caused by cold water being mixed in the pipes.
5. Ask the installer or gas company to check if there is
sufficient gas supply and gas pressure. If the load is
too low this will result in low water temperature
6. Is more hot water being used than was originally
estimated?
7. Inspect the heater for calcium desposition.
4.1.4. Water temperature too high
Check if the control thermostat has been set too high.
Diagram 17 – Resetting the Thermal Reflux System

20
Fault Possible cause Measure
Smelt of gas Gas leak. If you smell gas, close the main gas tap immediately,
do not light any flames, switch on any lights or operate any
other electrical switches or bells. Open windows. Contact
your installer or local gas company immediately.
Pilot light will Dirty pilot burner. Clean pilot burner.
not light or
goes out Blocked chimney. (Get someone to) Investigate the cause and rectify it.
Overheat thermostat is engaged. Allow the water in the heater to cool off and set a lower
water temperature
Faulty thermocouple. Replace thermocouple.
Thermocouple does not make contact. Repair connection.
Gas supple shut off. Open gas tap.
Faulty piezo ignition. Replace electrode.
Insufficient hot Temperature setting too low. Set a higher temperature.
water, or none
at all. Pilot light extinguished. Start heater.
Therminal Reflux Safeguard (TRS) has After resetting the TRS, restart the heater. If this happens
shut down heater. more often, call your installer.
Gas supply shut off. Open gas tap.
Overheat thermostat is/has been If necessary, allow the water in the heater time to cool
engaged. down and then set a lower temperature.
Supply of hot water exhausted. Reduce hoy water use. Give the heater time to heat up
the water.
Unidentifiable cause. Press red button all the way in. Close gas tap and call
your installer.
Water leakage Flue-gas condensation. See 'Condensation'
Water connections inadequately Tighten the screw thread connections.
sealed (screw thread)
Leakage from other water heaters or Track down the cause.
pipes in the vicinity
Explosive Wrong inlet gas pressure and/or burner Set correct inlet pressure and/or burner pressure.
ignition pressure.
Dirty injectors Clean injectors.
Poor flame Wrong inlet pressure and/or burner Set correct inlet pressure and/or burner pressure.
image pressure.
Inadequate air supply Improve air supply (ventilation).
4.2 FAULTOVERVIEW