andrews RSC 9/145 User manual

INSTALLATION AND SERVICE MANUAL
Pleasereadandunderstandtheseinstructionsbeforecommencinginstallationandleavethismanualwiththecustomerforfuturereference. 
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Andrews.Builttoperform.
CLASSICflo Balanced range
Issue 4 21042018

Andrews Water Heaters
Reproduction of any information in this publication by any
method is not permitted unless prior written approval has been
obtained from Andrews Water Heaters.
Andrews Storage Water Heaters have been designed and
manufactured to comply with current international standards of
safety. In the interests of the health and safety of personnel and
the continued safe, reliable operation of the equipment, safe
working practices must be employed at all times. The attention
of UK users is drawn to their responsibilities under the Health
and Safety Regulations 1993.
All installation and service on Andrews Water Heaters must be
carried out by properly qualified personnel and, therefore, no
liability can be accepted for any damage or malfunction caused
as a result of intervention by unauthorised personnel.
Andrews Water Heaters’ policy is one of continuous product
improvement and, therefore, the information in this manual,
whilst completely up to date at the time of publication, may be
subject to revision without prior notice.
Further information and assistance can be obtained from:
Customer support
Monday - Friday
8am - 5pm
Sales: 0345 070 1055
Technical: 0345 070 1057
Email: [email protected]
Website: www.andrewswaterheaters.co.uk
Twitter: @andrewsWH
Note
The Andrews Water Heaters covered in this manual
are for use with natural gas only
Copyright Andrews Water Heaters 2018
Issue 4 21042018

Contents

1.1General Information ............................................................................................................................ 4
1.2British Standards and Codes of Practice ............................................................................................ 4
1.3Health and Safety Regulations 1993 .................................................................................................. 5
1.4Effectiveness in Combating Legionella ............................................................................................... 5
2Technical Data............................................................................................................................................ 6
2.3ErP data .............................................................................................................................................. 9
3.2Location ............................................................................................................................................ 10
3.3Flue System ...................................................................................................................................... 10
3.4Flue Fitting Instructions..................................................................................................................... 12
3.5Air Supply.......................................................................................................................................... 13
3.6Important........................................................................................................................................... 14
3.7Water Quality and Treatment ............................................................................................................ 15
3.8Water Connections - General............................................................................................................ 16
3.9Gas Connections .............................................................................................................................. 19
3.10Electrical Supply ............................................................................................................................... 19
3.11Wiring Diagram ................................................................................................................................. 20
4Commissioning......................................................................................................................................... 21
4.1Commissioning ................................................................................................................................. 21
4.2Users Safety Guide........................................................................................................................... 22
5Operation ................................................................................................................................................. 23
5.1Burner Assembly
............................................................................................................................... 23
5.2Burner flame check ........................................................................................................................... 24
5.4Temperature selection procedure ..................................................................................................... 25
6.1Introduction ....................................................................................................................................... 30
6.2Burner Assembly............................................................................................................................... 32
6.3Gas Control Valve ............................................................................................................................. 33
6.4Magnesium Anode ............................................................................................................................ 34
6.5Descaling Information ....................................................................................................................... 34
6.6Accessing service mode on the water heater display (Service personnel only) ............................... 35
6.7How to reset the control from Lockout conditions ............................................................................. 44
6.8Diagnostic error codes and troubleshooting procedures for Honeywell integrated........................... 47
7Fault Finding ............................................................................................................................................ 49
7.1Fault Finding ..................................................................................................................................... 49
8Parts List .................................................................................................................................................. 50
8.1General Assembly............................................................................................................................. 50
8.2Control Box Assembly....................................................................................................................... 52
8.3General Assembly Parts List............................................................................................................. 53
9Appendix .................................................................................................................................................. 55
9.1Dismantling, Disposal and Recycling................................................................................................ 55
© Copyright ..................................................................................................................................................... 55
Issue 4 21042018

1 General and Safety Information
1.1 General Information
The Andrews Water Heater has been designed for use with
NATURAL GAS only and is manufactured to give an
efficient, reliable and long service life.
To ensure the continued, trouble-free operation of your heater at
maximum efficiency, it is essential that correct installation,
commissioning, operation and service procedures are carried
out strictly in accordance with the instructions given in this
manual. By law, installation and commissioning of the heater
must be carried out by properly qualified personnel.
The heater(s) must be installed in accordance with the following
requirements;
The current GAS SAFETY (INSTALLATION AND USE)
REGULATIONS
The current BUILDING REGULATIONS
The Water Supply (WATER FITTINGS) REGULATIONS 1999
Additionally, installation should be performed in accordance with
all relevant requirements of the Gas Supplier, Local Authority
and recommendations of the British Standards and Codes of
Practice detailed below.
1.2 British Standards and Codes of Practice
1.2.1 CLASSICflo Balanced
BS 6700: Specification for design, installation, testing
and maintenance of services supplying water
for domestic use within buildings and their
curtilages. This standard supersedes the
following British Standards and Codes of
Practice: CP99, CP310, CP324, 202, CP342
Part 2, Centralised Hot Water Supply.
BS 5440: Installation of flues and ventilation for gas
appliances of rated output not exceeding
60kW.
Part 1: Specification for installation of flues.
Part 2: Specification for installation of ventilation for
gas appliances.
BS 5546: Installation of gas hot water supplies for
domestic purposes.
BS 6891: Installation of low pressure gas pipework of up
to 28mm in domestic premises.
BS 7206: Specification for unvented hot water storage
units and packages.
BS EN 806 (Parts 1 - 5) Specifications for installations
inside buildings conveying water for human
consumption.
BS 6644 Installation of gas fired water boilers of rated
inputs between 70kW and 1.8MW.
BS EN 12897 Water supply. Specification for indirectly
heated unvented (closed) storage water
heaters.
IGE/UP/1A,1B Strength/tightness testing and direct purging.
IGE/UP/2 Installation pipework.
IGE/UP/10 - 1 (Edition 4): Installation of gas appliances in
industrial and commercial premises.
Note
Consideration should be given to amendments or
updates to the above standards.
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1.3 Health and Safety Regulations 1993
It is the duty of manufacturers and suppliers of products for use
at work to ensure, so far as is practicable, that such products
are safe and without risk to health when properly used and to
make available to users, adequate information about their safe
and proper operation.
Andrews Water Heaters should only be used in the manner and
purpose for which they were intended and in accordance with
the instructions in this manual. Although the heaters have been
manufactured with paramount consideration to safety, certain
basic precautions specified in this manual must be taken by the
user.
It is imperative that all users of the heater must be provided with
all the information and instruction necessary to ensure correct
and safe operation.
1.4 Effectiveness in Combating Legionella
Water systems in buildings have been associated with outbreaks
of Legionnaires' Disease, particularly in health care facilities
where occupants are significantly more susceptible to infection.
In recognition of the risks in hospitals, a Code of Practice for the
Control of Legionella in Health Care premises has been issued
by the Department of Health (1991). Codes of Practice
applicable to other premises have been published by other
organisations, principally the Health and Safety Executive
(HS)(G70) and the Chartered Institute of Building Services
Engineers (CIBSE, TM13).
All Codes of Practice draw attention to the design and operation
of water systems with reference to avoidance of factors that
favour colonisation by legionella bacteria. These factors include
stagnation, lukewarm conditions (20°C to 45°C) and the
accumulation of debris, scale and corrosion in the base of tanks
and calorifiers.
Andrews Water Heaters has commissioned an independent
evaluation of their products to investigate their resistance to
build-up of legionella bacteria.
Experiments were conducted to determine whether, following a
substantial challenge by legionella pneumophilia, after overnight
and stagnation conditions, the system was rendered free from
viable recoverable legionella. It was found that at 61°C, following
a challenge of approximately 107 organisms per litre, within one
hour, more than 99.999% of organisms had been killed. After a
subsequent stagnation period, sampling did not reveal any
residual contamination. The design of the base of the water
heater precludes legionella colonisation, even after build-up of
debris. The burner positioning ensures that the water at the
bottom of the heater reaches the same, or higher temperature
as in the rest of the heater.
Based on data obtained through experiment, the Andrews Water
Heater can be described as legionella resistant as it is
considered unlikely that, at the temperature tested, the organism
would colonise the water heater and present a possible health
risk.
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2 Technical Data
2.1 Appliance Dimensions
Model RSC 9/145 RSC 18/270
Amm 1276 1505
Bmm 559 559
Cmm 461.6 461.6
Dmm 1961 2190
Emm 1226 1226
Fmm 750 750
Gmm 854 854
Hmm 194 194
Imm 305 305
Jmm 610 610
Kmm The flue outlet can be installed in any
configuration through 180º as long as
proper service clearances are observed.
Lmm 203.2 203.2
Mmm 170 170
Fig.1
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2.2 CLASSICflo Balanced connections & technical data
Natural Gas
Andrews Models Unit RSC 9/145 RSC 9/180
Input (gross) kW 11.1 11.1
Input (net) kW 10.0 10.0
Output (gross) kW 8.88 8.88
Efficiency (Net CV) %88.80 88.80
Efficiency (Gross. thermal) %80 80
Gas Flow Rate m3/hr 0.93 0.93
Nominal Gas Inlet Pressure mbar 18 - 25 18 - 25
Main Burner Pressure mbar 12.0 12.0
NOx ppm 812
NOx mg/kWh 15 21
CO2 Flue Gas %7.50 - 9.00 7.50 - 9.00
Noise Level dBA 40 40
Recovery Rate (through 50°C rise) l/h 152 152
Recovery Rate (through 56°C rise) l/h 136 136
Minimum Flow Rate l/s N/A N/A
Water Content Litres 145 179
Weight Empty kg 71 79
Weight Full kg 216 258
Shipping Weight kg 80 89
Storage Losses kWh/l/day N/A N/A
Inlet/Outlet Connections Inch BSP 3/4” 3/4”
Return Connection Inch BSP 3/4” 3/4”
Gas Connection Inch BSP 1/2” 1/2”
Condensate Connection mm N/A N/A
Twin Pipe Conventional mm N/A N/A
Flue Diameter (concentric) mm 80 - 125 80 - 125
Ionisation Current (min) A0.8 0.8
Ionisation Current (max) A30 30
Electrical Requirements V230 230
Power Consumption W120 120
Fuse Rating A55
Maximum Flue Gas Temperature °C 300 300
Flue Static Pressure mbar N/A N/A
Waterside Pressure Loss kPa N/A N/A
Maximum Outlet Temperature °C 80 80
Maximum Working Pressure Bar 10.3 10.3
Minimum Working Pressure Bar 1.0 1.0
Diameter mm 559 559
Water Heater Height mm 1276 1505
Height to Vent Connection mm 1613 1842
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8
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2.3 ErP data
CLASSICflo Balanced Natural Gas RSC 9/145 RSC 9/180
Daily electricity consumption Qelec kWh
Declared load profile XL XL
Sound power level, indoors LWA dB 40 40
Daily fuel consumption Qfuel kWh 3030
Emissions of nitrogen oxides NOxmg/kWh 1521
Weekly fuel consumption with smart controls Qfuel, week, smart kWh --
Weekly electricity consumption with smart controls Qelec, week, smart kWh --
Weekly fuel consumption without smart controls Qfuel, week kWh --
Weekly electricity consumption without smart controls Qelec, week kWh --
Storage volume VI208 212
Mixed water at 40 °C V40 I165 193
Harmonised standards applied EN: 13203-2
Specific precautions that shall be taken when the water
heater is assembled, installed or maintained:
Before any assembly, installation or maintenance
the installation and operation manual has to be read
attentively and be followed
CLASSICflo Balanced RSC 9/145 RSC 9/180
Declared load profile XL XL
Water heating energy efficiency class
B
Water heating energy efficiency %6867
Annual energy consumption
kWh
(1)
6262
Annual energy consumption
GJ
(2)
2222
Other load profiles for which the water heater is suitable to use and the
corresponding water heating energy efficiency and annual electricity
- -
Thermostat temperature setting °C 60 60
Sound power level LWA indoors dB 40 40
Ability to off-peak hours functioning(3) --
Enables smart control settings(4) --
(1) Electricity
(2) Fuel
(3) If applicable.
(4) If smart control settings value is "1", the water heating energy efficiency and annual electricity and fuel consumption only relate to enabled smart control settings.
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3 Installation
3.1 Introduction
The law requires that installation is carried out by a
properly qualified person
Install in accordance with current British Standard Code of
Practice 342 part 2 and British Standards 5440, 5546, 6644,
6700, 6798 and 6891.
3.2 Location
The location chosen for the heater must permit the provision of a
satisfactory flue and an adequate air supply.
The heater must not be installed in a room which contains a
bath or a shower and must not be installed in a bedroom or
bedsitting room.
A clearance of 300mm should be left around the heater for fitting
and servicing purposes and 762mm above the heater for
removal of the flue baffle. The above clearances are
recommended for ease of servicing. They can be reduced if
necessary but a clearance of 300mm must be left in front of
heater for access to the burner and controls. The flue baffle
clearance should also be maintained if possible to avoid
servicing problems.
The floor on which the heater is installed must be flat, level and
of sufficient strength to withstand the weight of the heater when
filled with water, and should satisfy the requirements of the Local
Authority & Building Regulations.
Any combustible material adjacent to the heater must be so
placed or shielded as to ensure that its temperature does not
exceed 65°C.
3.3 Flue System
See
Detailed recommendations for flueing are given in British
Gas booklet IM/11 and BS 5440 part 1. The following
notes are intended to give general guidance:
Note
•Route. The route of the flue is not critical but, when
planning horizontal runs, potential condensate traps
must be avoided by maintaining a fall of 3° back to the
appliance.
When calculating maximum flue runs, a reduction
must be made of 2m per 90° bend and 1.5m per 45°
bend.
• Location. The siting of the flue terminal is not critical
with respect to the performance of the unit. However,
areas where the discharge of combustion products
would cause a nuisance should be avoided and it
should be positioned in the wall or roof correctly using
appropriate wall cover plates and flashing kits.
In accessible positions a suitable guard should be
provided.
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Fig. 2
Detailed recommendations for flueing are given in
British Gas booklet IM/11 and BS 5440 part 1.
The following notes are intended to give general
guidance:
Note
• A horizontal or vertical flue kit is supplied
with each heater. Flue fitting instructions on
page 12.
• Location. The siting of the flue terminal is
not critical with respect to the performance of the
unit. However, areas where the discharge of
combustion products would cause a nuisance
should be avoided. In accessible positions a
suitable guard should be provided. (see page 12).
• Route. The route of the flue is not critical,
with three installation options available. See below
for permissible flue lengths. Where installation
options 2 or 3 are used we recommend that the
flue outlet can be installed in any configuration
through 180° as long as proper service clearances
are observed, see fig.2.
Model RSC 9/145
Flueing Option Installation 1 Installation 2 Installation 3
Type of Flueing C31 C31 C11
Flue Restrictor Ø 45mm Ø 50mm Ø 60mm
A≤2.0 -≥0.5m and ≤1.0m
B-≤1.0m ≤1.0m
Model RSC 9/180
Flueing Option Installation 1 Installation 2 Installation 3
Type of Flueing C31 C31 C11
Flue Restrictor Ø 48mm Ø 55mm No restrictor required
A≤2.0 -≥0.5m and ≤1.0m
B-≤1.0m ≤1.0m
Roo B
600mm
A B
A Wall
Installation 1 Installation 2 Installation 3
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3.4 Flue Fitting Instructions
1. Fit heater adaptor D1 to heater ensuring correct location on
primary flue spigot from heater. (Use 4 self tapping screws
Fig. 3 provided).
2. Fit flue restrictor ring D7 into heater adaptor D1. The
correct size of restrictor for each heater model and
installation is shown on page 11.
3. Fit flue section D2 into heater adaptor D1.
4. Fit elbow D4 into flue section D2 for horizontal flue runs.
5. Determine correct position of flue outlet and fit outer wall
plate and inner wall plate. Fit flue outlet guard if required.
(Fixings not supplied).
6. Fit horizontal terminal D3 or make up lengths of flue required
(see page 11) into elbow D4. Each joint must be secured
with a sealed clamp D6.
7. For vertical installations fit flue lengths required (see page
11) into heater adaptor D1.
8. Determine correct position of flue terminal and fit either D8 or
D9 roof plates.
9. Fit D5 vertical terminal through roof plate into vertical flue
pipe.
10. Fit D6 sealed clamps on all joints.
11. On all installations the lengths of flue pipes may be cut to
obtain correct length of flue route required.
D8 D4
D9
D5
D2
D6
D6 D3 D10
D1 D7
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3.5 Air Supply
See
Detailed recommendations for air supply are given in BS
5440 part 2.
The following notes are intended to give general guidance:
Where the heater is to be installed in a room or internal space
the heater requires the room or internal space containing it to
have a permanent air vent. The vent must be either direct to
outside air or to an adjacent room or internal space which must
itself have a permanent vent of at least the same size direct to
outside air. The minimum effective area of the permanent air
vent(s) required is as follows:
5 cm
2
per kW in excess of 7 kW
Where the heater is to be installed in a compartment, permanent
air vents are required in the compartment at high and low level.
These air vents must either communicate with a room or internal
space or be direct to outside air.
The minimum effective areas of the permanent air vents
required in the compartment are as follows:-
Air Vent Areas
Position of Air Vents Air from room or internal space Air direct from outside
High Level 10cm
2
per kW 5cm
2
per kW
Low Level 20cm
2
per kW 10cm
2
per kW
Note
Both air vents must communicate with the same room or
internal space or must both be on the same wall to
outside air.
Where compartment air vents are open to a room or internal
space, the room or internal space must itself have a permanent
air vent(s) as previously specified.
For multiple installations where the total heat input exceeds 60
kW (204,720 BTU’s/hr), reference must be made to BS 6644.
The table on p7 should be used to calculate requirements.
Detailed recommendations are given in BS 6644 Clause 19.
The following notes are intended to give general guidance.
Ventilation shall prevent the heater environment from exceeding
32°C.
The purpose provided space housing the heater(s) must have
permanent air vents communicating directly with the outside air,
at high and low level. Where communication with the outside air
is possible only by means of high level air vents, ducting down
to floor level for the lower vents should be used.
For an exposed building, air vents should be fitted preferable on
all four sides, but on at least two sides.
Air vents should have negligible resistance and must not be
sited in any position where they are likely to be easily blocked or
flooded or in any position adjacent to an extraction system which
is carrying flammable vapour or other contaminated air.
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3.6 Important
The supply of air to a space housing the heater(s) by
mechanical means should be:-
a) Mechanical inlet with natural extraction.
b) Mechanical inlet with mechanical extraction.
NB - Natural inlet with mechanical extraction must not
be used.
Where a mechanical inlet and mechanical extraction system
is used, the design extraction rate must not exceed one third
of the design inlet rate.
All mechanical ventilation systems must be fitted with
automatic gas shut off safety systems which cut off the
supply of gas to the heater(s) in the event of failure of either
the inlet or extract fans.
NB - The vapours given off by halogen based
compounds can, if drawn into the combustion air, cause
corrosion of the Storage Vessel and premature failure of
the thermocouple.
If water heaters are to be installed in locations where
halogens are likely to be present they should be isolated
from such compounds and ventilated from and to outside,
uncontaminated, atmosphere.
Some of the vulnerable areas are listed below:-
i) Hairdressing salons and adjoining rooms and basements.
ii) Establishments where dry cleaning solutions are used or
stored.
iii) De-greasing pl ants using hydr ocarbon solvents.
iv) Premises where refrigerant gases are used or stored.
v) Environments with dust laden atmosphere
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3.7 Water Quality andTreatment
Where extreme conditions of water hardness exist, scale can
form in any water heating equipment, especially when the heater
is working under conditions of constant heavy demand and at
high temperatures.
Each water heater is fitted with one or more magnesium
anode(s) which protect the tank from corrosion caused by
electrolytic action. Magnesium anodes are sacrificial in that they
corrode as they protect. When the anode has eroded to less
than 50% of it's original diameter, it may not offer protection.The
anodes should be inspected annually and replaced as
necessary. Frequency of anode replacement will vary dependent
on water quality.
Andrews Water Heaters offer CorrexTM UP powered anodes as
an alternative to the standard magnesium anodes. These
anodes do not need maintenance or replacement. The
potentiostat which regulates the current to the CorrexTM anode,
features an indicator light which shows green to indicate correct
function and red to indicate malfunction. These anodes are
available as an optional extra on all Andrews heaters.
In hard water areas, scale formation can occur in hot water
systems and hot water heaters and the higher the temperature
and volume of water used, the more problematic the scale build-
up can be. Water treatment is normally recommended when the
hardness reaches 100 - 150ppm (7 - 10 degrees Clark) and
above. This problem can be minimised by reducing the water
temperature in the heater and by fitting suitable water pre-
treatment equipment.
Note
When installing Andrews Water Heaters in hard water
areas we would recommend that a water treatment
specialist is consulted.
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3.8 Water Connections - General
Fig. 4
3.8.1 Hydrojet® System
The heater is fitted with the Hydrojet® Total Performance System
incorporated in the cold inlet dip tube. The tube is designed to
increase turbulence and reduce sediment build up, reduce
thermal stacking and increase delivery.
The upper “jet ports”
direct the flow outward
to begin the dynamic
mixing action.
Fig. 5
The lower “jet ports”
direct the flow inward
to increase the
turbulence.
3.8.2 Water Connections - VentedSystems
The water heater must be supplied from a cold water feed
cistern and the hot water supply pipe must be fitted with an open
vent pipe in accordance with BS 5546. Local regulations and by-
laws must be observed when installing the system but typical
water service layouts are shown in Figs. 5.
The cold water feed cistern must have an actual capacity
greater than the hourly recovery rate of the heater or heaters to
which it is fitted, the minimum actual capacity allowed for a feed
cistern is 227 litres.
The actual cistern capacity is the capacity to the normal water
line of the cistern. All cisterns used should be to the relevant
British Standard and the distance from the normal water line to
the top of the cistern should be as laid down by the water
authorities.
The cold water inlet and hot water outlet are identified on top of
the heater. Connect the cold water feed and hot water outlet to
these nipples with union adaptors for ease of servicing.
See
See Servicing Section 6.
Caution
Do not apply heat to these nipples if making capillary
soldered joints as they are fitted with plastic inserts. Make
the capillary joints to the pipes before connecting to the
heater. A drain cock is supplied with the heater and this
should be fitted to the appropriate boss as shown on the
drawing.
After installation of the water system open the main water supply
valve, flush the system and fill the heater. Open the hot taps to
allow air to escape from the system. When the system is free of
air, close the taps and check for leaks at the gas control
thermostat, drain cock and pipe connections at the top of the
heater.
Stop valve
Open vent
Overflow
Hot water
service pipe
Cold water
feed
Cold water cistern
Cold water
inlet valve
Flue
Union
adaptor
Gas control thermostat
Secondary return
Check valve
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Fig. 6
Open vent
3.8.3 Water Connections - Unvented Systems
Unvented Systems should be fitted by an Approved Installer.
When used in an unvented system, the Andrews Water Heater
will supply hot water at a pressure of 3.5bar (50.8lbf/in
2
)
provided that this pressure is available at the mains feed. During
conditions of no-flow, system pressure may rise to a maximum
of 6bar (87lbf/in
2
) whilst the burner is operating. When testing
the system, it is recommended that a maximum test pressure of
8.62bar (125lbf/in
2
) is employed.
The heater can be used on unvented hot water storage systems,
with the addition of an Unvented Systems Kit, part number B171
available from Andrews Water Heaters.
All fittings and materials must be suitable for use with drinking
water and listed in the current Water Research Centre "Materials
and Fittings Directory".
Installation of unvented hot storage water systems must comply
with part G of Schedule 1 of the Current Building Regulations.
See
Fig.8 lists and illustrates the component parts of the
Unvented Systems Kit.
Fig.6 illustrates the general arrangement of the
components.
The Wall Mounting Kit is available as an optional extra.
Items D4/D6 must be fitted into the Temperature Relief
port (see Fig.6).
When assembling items D1 and D2 care must be taken to
ensure that the flow arrows marked on the components are
pointing in the direction of flow i.e. towards the water heater.
The cold water for services may be drawn from the 22mm
compression port on item D1(a). The water pressure at this point
will be similar to that available at the hot water outlet of the
water heater. If port (a) is not used it should be sealed with the
blanking plug supplied.
If higher flow rates are required for the cold water services a
suitable “tee” fitting should be included in the pipework upstream
of item D1.
The pipework fitted to both tundish outlets should be at least
28mm diameter and should be terminated at a suitable drain
(see Current Building Regulations Approved Document G3).
D3
Expansion
vessel
Balanced cold
water take-off
(if required)
D4
Temperature
pressure relief
valve
D7 Hose
assembly
D6
Cold water
inlet of
water
heater
D2 Check valve/
expansion valve
D5 tundish
D2 Pressure
reducing
valve
strainer
Cold water feed
Fig. 7
F3
Hot water service pipe F1
F5
F4
F2
Cold water
take off
F6
Secondary
return
Cold water inlet
Check valve
To drain
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F3
F4
F1
F7
F2
F5
F6
3.8.4 Unvented Systems Kit
Fig. 8
3.8.5 Unvented Systems Kit - Parts List
Ref. Part No. Description Qty
7703928 Unvented Systems Kit Complete 1
Comprises
F1&2 7705036 Pressure Reducing /Check/Exapnsion Valv
e
1
F3 7705037 Expansion Vessel 24L 1
F4 7705038 T/P Relief Valve 7 bar/95ºC x 3/4" 1
F6 7705039 Tundish 1
F5 7705040 Adaptor 3/4" 1
F7 7705041 Hose Assy 1
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3.9 Gas Connections
THE APPLIANCE MUST ONLY BE USED WITH NATURAL
GAS.
The installation of the gas supply should conform to the
requirements of IM/16 published by British Gas p.l.c. or BS
6891. Jointing compound used must conform to BS 5292 pt 5.
Caution
Do not apply heat in close proximity to the gas control as
this will result in damage occurring to the control.
Fit the 1⁄2 m/f elbow into the gas control valve. Fit the 1⁄2 gas
supply cock immediately upstream of the gas control and elbow
and connect to the gas supply. Pressure test the gas installation
for soundness. If any doubt exists as to size of gas supply pipe,
consult your local Gas Region.
It is recommended that a pressure test point is fitted on the input
next to the gas supply valve.
3.10 Electrical Supply
The method of connection to the mains electricity supply should
facilitate complete electrical isolation of the appliance preferably
by use of an unswitched fused spur.
Alternatively, a fused double pole switch or fused spur box,
serving only the heater, may be used. A 3mm separationis
required between each pole.
The point of connection to the mains should be readily
accessible and adjacent to the appliance.
Wiring external to the water heater must be installed in
accordance with the I.E.E. Regulations for the wiring of buildings
and to any local regulations that may apply.
The Heater is designed to run off a permanent 220/240V 1 Ph
50 Hz supply and the fuse rating is 3 Amp.
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3.11 Wiring Diagram
Fig. 9
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Issue 4 21042018