andrews RFF190 User manual

NATURAL GAS
FIRED STORAGE
WATER HEATERS
Models RFF190
RFF280
‘B’ Series
INSTALLATION
GUIDE,
OPERATION
AND SERVICE
MANUAL
THIS MANUAL MUST BE KEPT WITH THE APPLIANCE
June 2004 Part No. E515

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© Copyright Andrews Water Heaters 2004
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 U.K. users is
drawn to their responsibilities under the Health and Safety Regulations 1993.
All installation and service on the Andrews Water Heater 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.
The 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:
Andrews Water Heaters
Wednesbury One, Black Country New Road
Wednesbury, West Midlands WS10 7NZ
Tel: [phone] Fax: [phone]
Email: [email protected]
Website: www.andrewswaterheaters.co.uk
THE ANDREWS WATER HEATERS COVERED IN THIS MANUAL
ARE FOR USE WITH NATURAL GAS ONLY

CONTENTS
SECTION 1 GENERAL AND SAFETY INFORMATION
General Information 2
British Standards 2
Health and Safety Regulations 1993 3
Legionellae in Water Heaters 3
SECTION 2 TECHNICAL DATA
Appliance Dimensions 4
SECTION 3 INSTALLATION
Location 6
Flue Systems 6
Air Supply 7
Water Quality and Treatment 9
Water Connections 10
Vented Systems 10
Unvented Systems 11
Gas Connection 14
Electrical Supply 14
SECTION 4 COMMISSIONING
To light the Burner 16
To Shut Off the the Burner 16
Users Safety Guide 17
SECTION 5 OPERATION
To Check Main Burner Pressure 18
SECTION 6 SERVICING
Burner Assembly 19
Gas Control Valve 20
Flue Ways 20
Magnesium Anode(s) 21
Descaling Information 21
SECTION 7 FAULT FINDING 22
SECTION 8 PARTS LISTS AND ILLUSTRATIONS 24
PAGE

GENERAL AND SAFETY INFORMATIONSECTION 1
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.
BS 6700: 1997 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 1:2000 Specification for installation of flues.
Part 2:1989 Specification for installation of ventilation for gas appliances.
BS 5546:1990 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 7206:1990 Specification for unvented hot water storage units and packages.
I/M2 Purging procedures for non-domestic gas installations.
I/M5 Soundness testing procedures for industrial and commercial gas
installations.
I/M11 Flues for commercial and industrial gas fired boilers and air heaters.
I/M16 Notes on installation of gas pipework
(excluding 25mm and below).
NOTE: Consideration should be given to amendments or updates to the
above standards.
GENERAL
INFORMATION
BRITISH
STANDARDS
AND CODES OF
PRACTICE
2

GENERAL AND SAFETY INFORMATION SECTION 1
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.
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 Legionellae
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 (C1BSE, 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 Legionellae bacteria. These
factors include stagnation, lukewarm conditions (20ºC to 45ºC) 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 legionellae bacteria.
Experiments were conducted to determine whether, following a substantial challenge by
legionellae pneumophilia, after overnight and stagnation conditions, the system was
rendered free from viable recoverable legionellae. It was found that at 61ºC, 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
legionellae 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 legionellae resistant as it is considered unlikely that, at the temperature tested, the
organism would colonise the water heater and present a possible health risk.
HEALTH AND
SAFETY
REGULATIONS
1993
EFFECTIVENESS
IN COMBATING
LEGIONELLAE
3

TECHNICAL DATASECTION 2
APPLIANCE
DIMENSIONS
4
MODEL RFF190 RFF280
A mm 1448 1524
inches 57 60
B mm 158 158
inches 61⁄461⁄4
C mm 559 660
inches 22 26
D mm 279 279
inches 11 11
Emm 80 80
inches 3 3
F mm 1397 1397
inches 55 55
G mm 432 490
inches 17 191⁄4
H mm Min - Max 150 -300 150 - 300
inches Min - Max 6 - 12 6 - 12
J mm Min - Max 483 - 7000 533 - 4000
inches Min - Max 19 - 276 21 - 156
K mm 310 310
inches 121⁄4121⁄4
L mm 305 305
inches 12 12
M mm 345 396
inches 131⁄2151⁄2
N mm 275 326
inches 11 13
O mm 610 610
inches 24 24
J
HE
B
A
C
D
G
F
K
L
L
NO
L
M
MINIMUM SERVICE CLEARANCE
RECOMMENDED SERVICE CLEARANCE
RECOMMENDED SERVICE CLEARANCE
RECOMMENDED SERVICE CLEARANCE
RECOMMENDED SERVICE CLEARANCE
Fig 1.

Storage Capacity litre 190 280
gallons 42 62
Recovery thro' 44ºC/80ºF l/h 291 339
gal/h 64 75
Recovery thro' 56ºC/100ºF l/h 232 272
gal/h 51 60
Heat Input kW (Hs) 19.5 23
Btu/hr 66,534 78,476
Gas Flow Rate m3/hr 1.82 2.15
ft3 /hr 64.3 76
Flue Gas Temp. (Approx) ºC70 70
ºF 158 158
Flue Gas Volume m3/hr 32 29
Inlet & Flow Connections R 3/4 3/4
R (in BSPT/Ext) 3/4 3/4
Return Connection R (in BSP/Int) 3/4 3/4
Rp (in BSP P/Int) 3/4 3/4
Weight Empty kg 75 132
lb 165 292
Weight Full kg 273 418
lb 603 908
Max Working Pressure bar 10 10
psi 150 150
Max Test Pressure bar 20.6 20.6
psi 300 300
Gas Family 12H (Natural)
Gas Connection Rp 1/2 1/2
BSPT 1/2 1/2
Burner Pressure mbar 10.0 10.0
wg 4.0 4.0
Injector Diameter mm 3.90 4.20
No 24 19
Shipping Weight kg 84 144
lb 185 317
Shipping Dimension Carton mm 1785 x 600 x 660 1840 x 680 x 755
H x W x D in 70 x 24 x 26 72 x 27 x 30
Mains Voltage 220/240 - IP20
Frequency 50Hz
Power Consumption 236W
Fuse 5 amp
ANDREWS MODEL NO. RFF190 RFF280
TECHNICAL DATA SECTION 2
5

LOCATION
FLUE SYSTEM
RFF190 &
RFF280 FLUE
FITTING
INSTRUCTIONS
INSTALLATIONSECTION 3
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.
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 3OOmm (l2in) should be left around the heater for fitting and servicing
purposes and 762mm (3Oin) 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 3OOmm (12in) 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 65ºC (150ºF).
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:
•Route. The route of the flue is not critical but, when planning horizontal runs,
potential condensate traps must be avoided.
When calculating maximum flue runs, a reduction must be made of 1 metre run per
90°elbow and a 1/2 metre run per 45°elbow.
•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.
1. Fit spigot adaptor E4 to heater flue spigot in the direction shown. Note! Fire resistant
silicon sealant should be used on this joint.
2. Fit elbow E3 into spigot adaptor E4 for horizontal flue routes or E2 for vertical flue
routes.
3. Fit flue pipe into E2 to give required length of flue route. Refer to manual for
maximum horizontal and vertical flue routes.
4. Determine correct position and fit outer wall plate using 4 screws and rawplugs
provided. Cut flue sleeve to suit wall thickness and fit flue pipe through wall to outer
wall plate. Fit inner wall plate and fix using 4 screws and rawplugs provided.
5. The lengths of flue pipe may be cut to obtain correct length of flue route required.
6. On vertical flue installations it is important to fit the correct flue terminal E4 supplied
by Andrews Water Heaters.
7. For further information contact Andrews Technical Dept.
INTRODUCTION
6
E5
E1
E2 E2
E2
E3
E4
E2 Components
supplied
in Flue Kit

INSTALLATION SECTION 3
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 cm2per 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:-
7
AIR SUPPLY
FLUE SYSTEM
Air Vent Areas
Position of Air from room or Air direct from
Air Vents internal space outside
High Level 10 cm2per kW 5cm2per kW
Low level 20cm2per kW 10cm2per kW
(a Max)
(b Max)
0.3m
Fig 2.
Typical Flue
Installation
Size RFF190 RFF280
a8m 5m
b7m 4m

INSTALLATIONSECTION 3
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 (90°F).
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.
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
AIR SUPPLY
IMPORTANT
8

INSTALLATION SECTION 3
9
WATER
CONNECTIONS -
GENERAL
HYDROJET
SYSTEM
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.
When installing Andrews Water Heaters in hard water areas we would recommend
that a water treatment specialist is consulted.
The upper “jet ports”
direct the flow outward
to begin the dynamic
mixing action.
The lower “jet ports”
direct the flow
inward to increase
the turbulence.
How the system works
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.

INSTALLATIONSECTION 3
10
Fig 3.
WATER
CONNECTIONS -
VENTED
SYSTEMS
Open Vent
Overflow
Stop Valve
Cold Water Feed
Cold Water Cistern
Cold Water
Inlet Valve
Union
Adaptor
Hot Water
Service Pipe
Flue
Thermostat
Drain Cock
Gas Cock
Gas Control
Gas Supply Pipe
Check Valve
Secondary return via
Tee in Drain Port
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. 3 and 6.
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 (50 gall).
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 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.

INSTALLATION SECTION 3
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, 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.
Fig.4 p12 lists and illustrates the component parts of the Unvented Systems Kit.
Fig.5 p13 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, p13).
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).
11
WATER
CONNECTIONS -
UNVENTED
SYSTEMS

INSTALLATIONSECTION 3
12
Fig 4.
Unvented
Systems Kit
Unvented
Systems Kit
Ref. Part No. Description Qty
B171 Unvented Systems Kit Complete 1
D1 C780 Pressure Reducing Valve/Strainer 1
D2 C781 Check Valve / Expansion Vessel 1
D3 C782 Expansion Vessel 1
D4 E462 Temperature/Pressure Relief Valve 1
D5 C783 Tundish 1
D6 C772 Adaptor 1
B173 Wall Mounting Kit for Expansion Vessel
D7 C788 Hose Assembly 1
D8 C787 Wall Bracket Assembly 1

INSTALLATION SECTION 3
13
D3
D6 D2
D4
D5
D1
Fig 5.
Fig 6.
Cold Water Inlet
Cold Water Take Off
Hot Water Service Pipe
Check Valve
Secondary return via
Tee in Drain Port

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 1⁄2m/f elbow into the gas control valve. Fit the 1⁄2gas 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.
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 5 Amp.
Important Note
If the electrical power supply cable needs to be replaced it must be purchased from
the heater manufacturer.
INSTALLATIONSECTION 3
GAS
CONNECTIONS
ELECTRICAL
SUPPLY
14

WARNING -
DO NOT SWITCH OFF HEATER ELECTRICAL SUPPLY UNLESS CARRYING OUT
MAINTENANCE
INSTALLATION SECTION 3
15
Fig 7.