andrews 10/105 Manual

Issue 4 21/04/18
Please read and understand these instructions before commencing installation and leave this manual with the customer for future reference.
Andrews. Built to perform.

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: comm[email protected]
Website: www.andrewswaterheaters.co.uk
Twitter: @andrewsWH
Note
The Andrews Water Heaters covered in this manual
are for use with natural gas and LPG only
Copyright Andrews Water Heaters 2018

Contents
1.1 General Information.......................................................................................................................... 5
1.2 British Standards and Codes of Practice .......................................................................................... 5
1.3 Health and Safety Regulations 1993 ................................................................................................ 6
1.4 Effectiveness in Combating Legionella ............................................................................................. 6
2 Technical Data ......................................................................................................................................... 7
2.3 ErP data ......................................................................................................................................... 10
3 Installation ............................................................................................................................................. 11
3.1 Introduction .................................................................................................................................... 11
3.2 Location.......................................................................................................................................... 11
3.3 Assembling the draught diverter ..................................................................................................... 11
3.4 Air Supply....................................................................................................................................... 14
3.5 Important ........................................................................................................................................ 15
3.6 Water Quality and Treatment.......................................................................................................... 16
3.8 Water Connections - General ......................................................................................................... 17
3.8.1 Hydrojet® System ................................................................................................................... 17
3.9 Gas Connections............................................................................................................................ 20
3.10 Electrical Supply............................................................................................................................. 20
3.11 Wiring Diagram............................................................................................................................... 21
4 Commissioning...................................................................................................................................... 22
4.1 Commissioning............................................................................................................................... 22
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 .................................................................................................................... 53
8.3 General Assembly Parts List........................................................................................................... 54

9 Appendix ............................................................................................................................................... 57
9.1 Dismantling, Disposal and Recycling.............................................................................................. 57
© Copyright .................................................................................................................................................. 57

1 General and Safety Information
General and Safety Information 1
1.1 General Information
The Andrews Water Heater has been designed for use with
NATURAL GAS & LPG 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
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.
5

1 General and Safety Information
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.
6

2 Technical Data
Technical Data 2
2.1 Appliance Dimensions
Fig. 1
CLASSICflo 10/105, 10/145, 14/175
CLASSICflo 15/270 & 20/360
7

Recommended service clearance
Model 10/105 10/145 14/175 15/270 20/360
Amm 406.5 406.5 406.5 456.9 509.3
Bmm 200 200 200 262 260.4
Cmm 981 1041 1267 1319 1492
Dmm 1140 1222 1439 1515 1646
Emm 508 559 559 660 718
Fmm 1220 1303 1540 1595 1776
Gmm 762 762 762 1143 1270
Hmm 102 102 102 125 125
Imm 203 203 279 279 406
Jmm 305 305 305 305 305
Kmm 610 610 610 610 610
Lmm --- --- 340 424 435
8

2 Technical Data
2.2 CLASSICflo connections & technical data
Natural Gas
Andrews Models Unit CLASSICflo
CLASSICflo
CLASSICflo
CLASSICflo
CLASSICflo
10/105 10/145 14/175 15/270 20/360
Input (gross) kW 12.3 12.9 17.6 19.0 24.9
Input (net) kW 11.1 11.6 15.8 17.1 22.4
Output (gross) kW 9.84 10.32 14.08 15.2 19.92
Efficiency (net) %88 88 88 88 88
Efficiency (gross) %80 80 80 80 80
Gas Flow Rate (NG) m3/hr 1.03 1.08 1.47 1.59 2.08
Gas Flow Rate (LPG) m3/hr 0.38 0.42 0.55 0.60 0.79
Main Burner Pressure mbar 12.0 12.0 12.0 12.0 12.0
NOx (NG) ppm 12 19 23 14 17
NOx (NG) mg/kWh 21 33 40 25 31
NOx (LPG) ppm 96 148 70 98 93
NOx (LPG) mg/kWh 169 260 123 173 164
CO2 Flue Gas (NG) %7.00 - 9.00 8.00 - 9.00 8.50 - 9.90 8.00 - 9.00 7.50 - 9.70
CO2 Flue Gas (LPG) % 8.50 - 9.50 10.00 - 10.50 8.50 - 9.50 9.00 - 9.50 8.50 - 9.50
Noise Level dBA 40 40 40 40 40
Recovery Rate (through 50°C rise) l/h 169 177 241 261 341
Recovery Rate (through 56°C rise) l/h 151 158 216 233 305
Minimum Flow Rate l/s N/A N/A N/A N/A N/A
Water Content Litres 105 144 175 270 360
Weight Empty kg 55 65 82 111 153
Weight Full kg 159 209 257 380 512
Shipping Weight kg 64 74 91 120 188
Storage Losses kWh/l/day 0.14 0.14 0.19 0.23 0.32
Inlet/Outlet Connections Inch BSP 3/4” 3/4” 3/4” 1” 1.25”
Return Connection Inch BSP 3/4” 3/4” 3/4” 1” 1.25”
Gas Connection Inch BSP 1/2” 1/2” 1/2” 1/2” 1/2”
Condensate Connection mm N/A N/A N/A N/A N/A
Twin Pipe Conventional mm N/A N/A N/A N/A N/A
Flue Diameter (secondary) mm 100 100 100 125 125
Flue Diameter (concentric) mm N/A N/A N/A N/A N/A
Ionisation Current (min) µA0.8 0.8 0.8 0.8 0.8
Ionisation Current (max) µA30 30 30 30 30
Electrical Requirements V230 230 230 230 230
Power Consumption W120 120 120 120 120
Fuse Rating A33333
Maximum Flue Gas Temperature °C 300 300 300 300 300
Flue Static Pressure mbar N/A N/A N/A N/A N/A
Waterside Pressure Loss kPa N/A N/A N/A N/A N/A
Maximum Outlet Temperature °C 80 80 80 80 80
Maximum Working Pressure Bar 10.3 10.3 10.3 10.3 10.3
Minimum Working Pressure Bar 1.0 1.0 1.0 1.0 1.0
Diameter mm 508 559 559 660 718
Water Heater Height mm 1130 1200 1432 1527 1692
Height to Vent Connection
mm
1242 1311 1532 1629 1845
9

2.3 ErP data
CLASSICflo 10/105
10/145 14/175 15/270 20/360
Declared load profile XL
XL
XL
XL
XL
Water heating energy efficiency class
B
Water heating energy efficiency %63 64 63 60 62
Annual energy consumption
kW
h
(1)
63 64 60 65 61
Annual energy consumption
GJ
(2) 23 22 24 24 24
Other load profiles for which the water heater is suitable to use and the corresponding
water heating energy efficiency and annual electricity consumption(3)
-----
Thermostat temperature setting °C 60 60 60 60 60
Sound power level L
WA
indoors
dB
40
40 40 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.
CLASSICflo Natural Gas
10/105
10/145
14/
175
15/270
20/360
Daily electricity consumption Qelec kWh 0.17 0.17 0.16 0.18 0.17
Declared load profile
Sound power level, indoors LWA dB
40
40 40 40 40
Daily fuel consumption Qfuel kWh 33 33 33 35 36
Emissions of nitrogen oxides NOxmg/kW
h
21 33 40 25 31
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 VI105 144 175 270 360
Mixed water at 40 °C V40 I120 195 240 498 1075
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
10

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 suitable clearance should be left around the heater for fitting
and servicing purposes. The above clearances given on page 7
are recommended for ease of servicing. They can be reduced if
necessary but a clearance of 610mm 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 Assembling the draught diverter
The draught diverter must be assembled with the legs provided.
Attach the legs to the draught diverter with the nuts and bolts
provided.
Fit the draught diverter (1) as shown in Fig.1 to the water
heater using the screws provided. For Standard Range fit the
draught diverter to the top of the water heater using the
location holes
In some cases, it may be necessary to drill the fixing holes in
the top cover to fit the draught diverter to the water heater.
By using the draught diverter as a template, position
carefully over the flueway and mark the hole positions to be
drilled 4mm
Fit the adaptor socket (2) and seal into the draught diverter
as shown and attached flue spillage thermostat (3) to the
draught diverter with the bolts provided
2
1
Outlet Intlet
Fig.1
3
11

3 Installation
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Guidance for flue installation are given in BS 6644, BS5440
Pt 1 and British Gas publication IM/11 - Flues for Commercial
and Industrial Gas Fired Boilers and Air Heaters.
The flue connection is designed for BS 835 type heavy duty
flue, but light quality flue pipe, mild steel or stainless steel
sheet may be used using the appropriate adapter. Flue pipes
etc. shall be fitted socket-up to keep any condensate within
flue and appliance. Flues up to 200mm diameter should be
fitted with a suitable British Gas Certified terminal.
Fig 2.
The terminal position is most important and must be at least
1000mm above roof surfaces or at least 600mm above any
parapet and clear of any adjacent obstruction as well as
being clear of any openable windows, ventilators or features
which could allow re-entry of flue products into the building.
Pressure areas should also be avoided to prevent
blowdown.
See recommendations in BS 6644. BS 5440 Part 1
also provides useful additional advice.
Flue materials, including jointing materials and fittings shall
be asbestos-free, robust, durable, corrosion resistant and
non- combustible and shall comply with BS 5854 and BS 715
or BS 4076 as appropriate, as well as being of a type
accepted by the Local Gas Authority.
When passing up through or adjacent to combustible
materials, measures shall be taken to prevent the temperature
of the combustible material from exceeding 60°C. The flue
shall not be closer than 50mm to any combustible material
except when passing through, when it must be enclosed by a
non- combustible sleeve and separated from the sleeve by not
less than 25mm air space.
Flues shall be of a size not less than specified in Section 2,
Technical Data (i.e. nominal flue size) and fitted so that there
is no risk to persons in the building or from accidental damage
Fig 3.
If using an existing brick chimney, it should be swept and
lined and checked for soundness before connecting the flue
and should take the shortest possible route and rise
continuously to the terminal avoiding the use of 90° bends
where a change of direction is required. Horizontal and very
shallow runs of flue should be avoided since they impede the
flow of gases and increase local cooling.
*A minimum of 600mm of vertical flue directly above the
draught diverter should be provided where possible on all
natural draught flue installations. If this dimension cannot be
achieved please contact Andrews Water Heaters.
Note
Please note this is not required where a common flue
header is used on multiple installations.
Terminal
1000mm
Minimum
Roof
1 2 3
Split flue clip
600mm*
1. This flue run
must not be used
2 & 3 are recommended flue runs
Fig.2
Fig.3
12

Minimum Heights from Roof to Base of Flue Terminal
Type of Roof
Not within 1.5m of a
vertical surface of a
structure = on the roof
Within 1.5m of a
vertical surface of a
structure = on the roof
Internal Route External
Route
Internal
Route
External
Route
On Ridge Not on Ridge
Pitched
Pitch
exceeding
45°
At or
above
ridge
level
1m
above roof
intersection
1m
above roof
intersection
The base of the
terminal should
be 600mm
above the level of
the adjacent roof
edge
Pitch not
exceeding
45°
600mm
above roof
intersection
The base of
the terminal
should be
600mm
above the
level of the
adjacent
roof edge
Flat
With
parapet
Not
applicable
600mm
above roof
intersection
Without
parapet
250mm
above roof
intersection
Each unit has an
atmospheric burner
system & uses natural
gas.
Heater with
highest usage
fitted nearest to
main flue
(if applicable)
Fig 4.
Common flues may be used on multiple installations
only if all the heaters are of the same burner system
and fuel type and should be sized to ensure complete
evacuation of the flue products from the installation.
Where one flue is to be used more regularly or for
longer periods than the others in the group, it should
be connected at the point nearest to the main flue
See BS 6644 Clause 20 for further
information and recommendations on this
as well as general flue requirements.
Fit a flue clip or flange joint close to the diverter
so that it is secure but can be disconnected for
servicing. The weight of the flue must be borne
by securing clips, etc. and not by the heater
Fig.4
13

3.4 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 cm2 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 10cm2 per kW 5cm2 per kW
Low Level 20cm2 per kW 10cm2 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.
14

3.5 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 plants using hydrocarbon solvents.
iv) Premises where refrigerant gases are used or stored.
v) Environments with dust laden atmosphere
15

3.6 Water Quality and Treatment
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.
16

3.8 Water Connections - General
Fig. 5
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. 6
The lower “jet ports”
direct the flow inward
to increase the
turbulence.
3.8.2 Water Connections - Vented Systems
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
bye-laws must be observed when installing the system but
typical water service layouts are shown in Figs. 6 and 8.
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.
17

Fig. 7
Fig. 8
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/in2)
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/in2) whilst the burner is operating. When testing
the system, it is recommended that a maximum test pressure of
8.62bar (125lbf/in2) is employed.
The heater can be used on unvented hot water storage systems,
with the addition of an Unvented Systems Kit, 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.7).
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
18

D3
D4
D1
D2
D7
D6
D5
3.8.4 Unvented Systems Kit
Fig. 9
3.8.5 Unvented Systems Kit - Parts List
Ref. Part No. Description Q
t
7703928 Unvented Systems Kit Complete 1
D1 7705036 Pressure Reducing Valve / Check Valve / Expansion Valve 1
D2 7705037 Expansion Vessel 24L 1
D3 7705038 Temperature / Pressure Relief Valve 1
D4 7705039 Tundish 1
D5 7705040 Adaptor 1
D6 7705041 Hose Assembly 1
19

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 separation is
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.
20