VOKERA AquaNova Release note

Installation
& Servicing
Instructions
THESE INSTRUCTIONS
TO BE RETAINED
BY USER
Vokèra is a licensed member of the Benchmark scheme
which aims to improve the standards of installation and
commissioning of domestic hot water systems in the UK.
AquaNova
Water heater

Contents
Design principles & operating sequence Page
1.1 Principle components 2
1.2 Mode of operation 2
1.3 Safety devices 2
Technical data Page
2.1 Performance 3
2.2 Gas pressure 3
2.3 Dimensions 3
2.4 Clearances 3
2.5 Connections 3
2.6 Electrical 3
2.7 Flue details 3
General requirements Page
3.1 Related documents 4
3.2 Location of appliance 4
3.3 Gas supply 4
3.4 Flue system 4
3.5 Air supply 4
3.6 Water pipe work 4
3.7 Electrical supply 5
3.8 Timber framed buildings 5
Installation Page
4.1 Delivery 5
4.2 Contents 5
4.3 Unpacking 5
4.4 Preparation for mounting the appliance 5
4.5 Fitting the flue 6
4.6 Connecting the gas & water 10
4.7 Electrical connections 10
Commissioning Page
5.1 Gas supply installation 11
5.2 Water pipe work 11
5.3 Pre-operation checks 11
5.4 Initial lighting 11
5.5 Checking the burner pressure 11
5.6 Setting the outlet temperature 11
5.7 Final checks 11
5.8 Instructing the user 11
Servicing Page
6.1 General 12
6.2 Routine annual servicing 12
6.3 Replacement of components 12
6.4 Component removal procedure 12
6.5 NTC thermistors removal 12
6.6 High limit thermostat removal 12
6.7 Flow switch removal 12
6.8 Gas valve removal 13
6.9 Burner, injectors and spark/sense electrode removal 13
6.10 Flue fan removal 13
6.11 Heat exchanger removal 14
6.12 Air pressure switch removal 14
Checks, adjustments, and fault finding Page
7.1 Checking appliance operation 14
7.2 Appliance mode of operation 14
7.3 Checking/adjusting burner pressure 14
7.4 External faults 15
7.5 Electrical checks 15
7.6 Fault finding 15
7.7 Fault codes 16
Wiring diagrams Page
8.1 External wiring 21
Exploded diagrams Page
9.1 Table 1 23
9.2 Table 2 24
L.P.G. instructions Page
10.1 Technical data 25
10.2 Related documents 25
10.3 Gas supply 25
10.4 Gas supply installation 25
10.5 Checking/Adjusting the burner pressure 25

1
INTRODUCTION
General layout
1 Gas valve
2 High limit thermostat
3 Electrode
4 NTC sensor
5 Pressure differential switch
6 Silicone pressure tube (+)
7 Silicone pressure tube (-)
8 Fan assembly
9 Heat exchanger
10 Main burner
11 Flow switch
TheVokeraAquaNovaisaninstantaneouswaterheater,
which - by design - incorporates electronic ignition, NTC
temperature control, continuous gas modulation, and
status/fault indicators.
Itisproducedasaroomsealed,categoryII2H3+appliance,
suitableforwallmountingapplicationsonly.Itisprovided
with a fan powered flue outlet with an annular co-axial
combustionairintakethat can be rotated – horizontally–
through 360 degrees for various horizontal or vertical
applications.
TheAquaNovacanalsobeusedwiththeVokeratwinflue
system.
Fig. 1

2
SECTION 1 DESIGN PRINCIPLE AND OPERATING SEQUENCE
1.1 PRINCIPLE COMPONENTS
●A fully integrated electronic control board
featuring electronic temperature control, self-
diagnostic fault indicator, continuous gas
modulation.
●Electronic ignition with flame supervision.
●Fan.
●Differential air pressure switch.
●Two-stage gas valve.
1.2 MODE OF OPERATION
When there is a request for hot water via a hot
water outlet or tap, the water flow switch senses
water movement thereby energising the fan, the
fan proves the differential air pressure switch
whichin-turnallowsanignitionsequencetobegin.
Ignition is sensed by the electronic circuitry to
ensure flame stability at the burner. Once
successful ignition has been achieved, the
electronic circuitry increases the gas rate to
maximumormodulatestosuitthesetrequirement.
When the appliance reaches the desired
temperaturetheburner will modulatetomaintain
thedesiredtemperature.Shouldthetemperature
continuetoincrease,theburnerwillshutoffwhen
the maximum operating temperature is attained.
Whentherequestforhotwaterhasbeensatisfied
the appliance fan may continue to operate to
dissipate any residual heat within the appliance.
1.3 SAFETY DEVICES
When the appliance is in use, safe operation is
ensured by:
●a high limit thermostat that over-rides the
temperaturecontrolcircuittopreventorinterrupt
the operation of the burner;
●adifferentialairpressureswitchthatchecksthe
operation of the fan and flue thereby allowing
safe operation of the burner;
●a flame supervision device that will shut off the
gas supply to the burner if there is no flame
sensed within 7 seconds.
Fig. 2
inlet cold water
Fan assembly
Air pressure switch
outlet cold water
Heat exchanger
Burner
Flow regulator
Gas
Flow switch
High limit thermostat
NTC sensor

3
SECTION 2 TECHNICAL DATA
2.1 Performance
Heat input 32,0 kW
Heat output (max) 28,8 kW
Heat output (min) 10,0 kW
Minimum working pressure 0,15 kW
Maximum working pressure 10,0 bar
Minimum flow rate 2 litres per minute
Hot water - 35°C temperature rise 11,8 litres per minute
2.2 Gas pressure
Inlet pressure (G20) 20,0 mbar
Maximum burner pressure 12,0 mbar
Minimum burner pressure 1,5 mbar
Gas rate 3,5 m3/h
Injector size 15 x 1,30mm
2.3 Dimensions
Height 640 mm
Width 400 mm
Depth 246 mm
Weight 20 kg
2.4 Clearances
Top 150 mm from casing or 25 mm above
flue elbow (whichever is applicable)
Bottom 150 mm
Sides 50 mm
Front 600 mm
2.5 Connections
Cold water inlet 15 mm (compression)
Hot water outlet 15 mm (compression)
Gas 15 mm copper
2.6 Electrical
Voltage 230V/~ 50hz
Power consumption 85 W
Internal fuse 2 AF
External fuse 3 A
2.7 Flue details
Maximum horizontal flue length (concentric) 2,4 metres
Minimum horizontal flue length (concentric) 0,4 metres
Maximum vertical flue length (concentric) 3,6 metres
Minimum vertical flue length (concentric) 1,0 metres
Maximum twin flue length (horizontal or vertical) 5m/5m + terminal
Fig. 3
Terminal position for fan assisted boiler
(minimum distance) mm
A - Directly above or below an open window 300
or other opening (e.g. air brick)
B - Below gutters, soil pipes or drain pipes 25
C - Below eaves 25
D - Below balconies or car port roof 25
E - From vertical drain pipes and soil pipes 75
F - From internal or external corners 25
G - Above ground or below balcony level 300
H - From a surface facing a terminal 600
I - From a terminal facing a terminal 1200
J - From an opening in the car port (e.g. door
window) into dwelling. 1200
K - Vertically from a terminal on the same wall 1500
L - Horizontally from a terminal on the same wall 300
M - Horizontally from a vertical terminal to a wall 300
N - Horizontally from an opening, airbrick,
openable window, etc. 300
NOTE: The flue must be terminated in a place not likely to cause a
nuisance.
N
New minimum distance

4
This appliance must be installed by a competent
personinaccordancewiththeGasSafety(Instal-
lation & Use) Regulations.
3.1 RELATED DOCUMENTS
The installation of this water heater must be in
accordancewiththerelevantrequirementsofthe
Gas Safety (Installation & Use) Regulations, the
Water supply (water fittings) Regulations, the
WaterByelawsScotland,theBuildingStandards
(Scotland) Regulation and Building Standards
(Northern Ireland) Regulations.
Itshouldbeinaccordancealsowithanyrelevant
requirementsofthelocalauthorityandtherelevant
recommendationsofthefollowingBritishStandard
Codes of Practice.
3.2 LOCATION OF APPLIANCE
The appliance may be installed in any room or
internal space, although particular attention is
drawn to the requirements of the current I.E.E.
wiringregulations,and in Scotland, the electrical
provisions of the Building Regulations, with
respect to the installation of the appliance in a
roomorinternalspacecontainingabathorshower.
When an appliance is installed in a room or
internal space containing a bath or shower, the
appliance or any control pertaining to it must not
be within reach of a person using the bath or
shower.
Thelocationchosenfortheappliancemustpermit
the provision of a safe and satisfactory flue and
termination. The location must also permit an
adequate air supply for combustion purposes
and an adequate space for servicing and air
circulation around the appliance. Where the
installation of the appliance will be in an unusual
location special procedures may be necessary,
BS 6798 gives detailed guidance on this aspect.
A compartment used to enclose the appliance
must be designed and constructed specifically
for this purpose. An existing compartment/cup-
board may be utilised provided that it is modified
to suit.
Details of essential features of compartment/
cupboard design, including airing cupboard in-
stallations, are given in BS 6798. This appliance
is not suitable for external installation.
3.3 GAS SUPPLY
The gas meter – as supplied by the gas supplier
–mustbecheckedtoensurethatitisofadequate
size to deal with the maximum rated input of all
the appliances that it serves. Installation pipes
must be fitted in accordance with BS 6891.
Pipe-work from the meter to the appliance must
be of adequate size. Pipes of a smaller size than
the appliance gas inlet connection must not be
used. The installation must be tested for sound-
ness in accordance with BS 6891.
Ifthegassupplyservesmorethanoneappliance,
it must be ensured that an adequate supply is
maintained to each appliance when they are in
use at the same time.
3.4 FLUE SYSTEM
Theterminalshouldbelocatedwherethedisper-
sal of combustion products is not impeded and
withdueregardforthedamageanddiscoloration
thatmayoccurtobuildingproductslocatednearby.
Theterminalmustnotbelocatedinaplacewhere
it is likely to cause a nuisance (see fig. 3).
In cold and/or humid weather, water vapour may
condense on leaving the terminal; the effect of
such pluming must be considered.
If installed less than 2m above a pavement or
platform to which people have access (including
balconies or flat roofs) the terminal must be
protected by a guard of durable material. The
guard must be fitted centrally over the terminal.
RefertoBS5440Part 1, when the terminal is 0,5
metres(orless)belowplasticguttering or1metre
(or less) below painted eaves.
3.5 AIR SUPPLY
The following notes are intended for general
guidance only.
This appliance is a room sealed, fan-flued water
heater, consequently it does not require a
permanent air vent for combustion air supply.
When installed in a cupboard or compartment,
ventilationforcoolingpurposesisalsonotrequired.
3.6 WATER PIPE WORK
Detailedrecommendationsare given inBS5449
Part 1 and BS 6798. The following notes are for
general guidance only.
3.6.1 PIPEWORK
ItisrecommendedthatcoppertubingtoBS2871
Part 1 is used in conjunction with soldered capil-
lary joints.
Where possible pipes should have a gradient to
ensureairiscarriednaturallytoanoutletandthat
water flows naturally to drain cocks.
SECTION 3 GENERAL REQUIREMENTS
BS 5440 PART 1 FLUES
BS 5440 PART 2 FLUES AND VENTILATION
BS 5546 INSTALLATION OF HOT WATER SUPPLIES FOR DOMESTIC PURPOSES
BS 6891 LOW PRESSURE INSTALLATION PIPES
BS 6700 DESIGN, INSTALLATION, TESTING AND MAINTAINENCE OF SERVICES SUPPLYING
WATER FOR DOMESTIC USE

5
Pipes should be insulated to avoid heat loss and
in particular to avoid the possibility of freezing.
Particularattentionshouldbepaidtopipespassing
throughventilatedareassuchasunderfloors,loft
space, and void areas.
3.6.2 DRAIN COCKS
Thesemust be located in accessiblepositions to
facilitate draining of the appliance and all water
pipes connected to the appliance. The drain
cocks must be manufactured in accordance with
BS 2879.
3.7 ELECTRICAL SUPPLY
The appliance is supplied for operation on 230V
@ 50Hz electrical supply; it must be protected
with a 3-amp fuse. The method of connection to
the mains electricity supply must allow for
completeisolationfromthesupply.Thepreferred
method is by using a double-pole switch with a
contact separation of at least 3mm. The switch
must only supply the appliance. Alternatively an
un-switched shuttered socket with a fused 3-pin
plugboth complying with BS 1363is acceptable.
Fig. 4
4.1 DELIVERY
The appliance is delivered in a heavy-duty card-
board carton. Lay the carton on the floor with the
writing the correct way up.
4.2 CONTENTS
Contained within the carton is:
●the appliance;
●the wall mounting bracket;
●template;
●an accessories pack containing the appliance
service valves and washers;
●the instruction pack containing the installation
&servicinginstructions,userinstructionsanda
3-amp fuse.
4.3 UNPACKING
At the top of the carton pull both sides open – do
notuseaknife–unfoldtherestofthecartonfrom
around the appliance, carefully remove all pro-
tectivepackagingfromtheappliance,andlaythe
accessories etc. to one side.
4.4 PREPARATION FOR MOUNTING THE
APPLIANCE
The appliance should be mounted on a smooth,
vertical, surface, which must be capable of
supporting the full weight of the appliance. Care
shouldbeexercisedwhendeterminingtheposition
of the appliance with respect to hidden
obstructions such as pipes, cables, etc.
When the position of the appliance has been
decided–usingthetemplatesupplied–carefully
mark the position of the wall-mounting bracket
(see fig. 5) and flue-hole (if applicable).
3.8 TIMBER FRAMED BUILDINGS
Iftheapplianceistobefittedinatimberframed
building, it should be fitted in accordance with
theInstituteofGasEngineerspublication(IGE/
UP/7) “Guide for Gas Installations in Timber
Frame Buildings”.
SECTION 4 INSTALLATION
Fig. 5
1= centre of rear flue hole using ONLY 0225705 or 0225710 flue
2= centre of rear flue hole for ALL OTHER FLUES
ø 125
ø 6
ø 6
Type 2
Type 1
320
45
86131
614,5
803
57,5
74 74

6
4.4.1 IMPORTANT
There are two holes on the template.
The lower hole should be used with the
telescopicfluekit(partn°0225705&0225710).
The upper hole is for use with all other
horizontal flue kits.
4.4.2 MAXIMUM FLUE LENGTHS
4.5 FITTING THE FLUE
The top flue outlet permits both horizontal and
vertical flue applications to be considered,
alternatively, the Vokera twin flue system can be
utilised if longer flue runs are required.
4.5.1 CONCENTRIC HORIZONTAL FLUE
(For concentric vertical flue, see 4.5.2).
(For twin flue applications, see 4.5.3).
The appliance flue outlet elbow can be rotated
through 360°on its vertical axis. In addition the
fluemaybeextendedfromtheoutletelbowinthe
horizontalplane(see4.4.2),howeveriftheflueis
to be extended or additional bends are to be
fitted, the standard horizontal flue kit (part n°
2359029) must be used. A reduction must also
bemadetothemaximumlength(seetable)when
additional bends are used.
Using the template provided, mark and drill a
115mmholeforthepassageofthefluepipe.The
hole should have a 1°drop from the boiler to
outside, to eliminate the possibility of rainwater
entering the appliance via the flue.
The fixing holes for the wall-mounting bracket
should now be drilled and plugged, an
appropriate type and quantity of fixing should be
used to ensure that the bracket is mounted
securely. Once the bracket has been secured to
the wall, mount the appliance onto the bracket.
Flue system
Concentric Horizontal
Concentric Vertical
Twin flue
AquaNova
2,4m
3,6m
5m/5m + terminal
Reduction for bends
Bend
45°bend
90°bend 0,5 metre 1,0 metre
Reductionin maximumflue length foreach bend
Horizontal flue terminals and accessories
PartNo. Description Min-Max length
0225705
0225710
2359029
2359069
2359079
2359049
2359059
0225760
Standard telescopic flue
Extended telescopic flue
Horizontal flue kit for use with
add. bends & extensions
750mm extension
1500mm extension
45°bend (pair)
90°bend
Wall bracket (5)
380mm-600mm
(dimension X)
600mm-920mm
(dimension X)
833mm
(dimension X)
750mm
1500mm
N/A
N/A
N/A
IMPORTANT
The flue restrictor ring must be inserted into the
appliance flue outlet if the total flue length is less
than 1.0m
FITTING THE TELESCOPIC FLUE KIT
(0225705 & 0225710)
Carefully measure the distance from the centre
of the appliance flue outlet to the face of the
outside wall (dimension X see fig. 6).Add 50mm
to dimension X to give the overall flue length
(dimensionY).Usingthecomplete telescopic flue
assembly adjust the length to suit dimension Y.
Once the telescopic flue terminal has been
adjusted to the correct length, secure the flue
assembly with the screw supplied.
Inserttheflueassembly into the previously drilled
flue hole and locate the flue bend over the
appliance flue outlet. Push the flue bend down
over the appliance flue outlet and ensure the
correct seal is made. Pull the flue assembly
towards and over the flue bend - using a twisting
action-ensuringthecorrectsealis made. Check
that the terminal protrudes past the finished
outside wall by the correct length (115mm).
NOTE
You must ensure that the entire flue system is
properly supported and connected.
Seal the flue assembly to the wall using cement
or a suitable alternative that will provide
satisfactory weatherproofing. The interior and
exterior trim can now be fitted.
FITTING THE STANDARD (2359029)
HORIZONTAL FLUE KIT (see 4.4.1)
Carefully measure the distance from the centre
of the appliance flue outlet to the face of the
outside wall (dimension X see fig. 7). Ensure the
inner (60mm) pipe is fully inserted into the outer
(100mm) pipe (when the inner pipe is fully
inserted, it stands proud of the outer pipe by
7,5mm). Add 32mm to dimension X to give the
overall flue length (dimension Y). The standard
horizontal flue kit (part no. 2359029) is suitable
for a distance (dimension Y) of up to 865mm.
NOTE
Dimension Y is measured from the end of the
terminal to the end of the outer (100mm) pipe.
The internal trim should be fitted to the flue pipe
before connection of the 90°bend.
115 mm
“X”
“Y”
Fig. 6 “X” + 50 mm = “Y”

7
If the horizontal flue kit (2359029) requires to be
cut to the correct size (dimension Y), you must
ensure that the inner (60mm) pipe stands proud
oftheouter(100mm)pipeby 7,5 mm (see fig. 8).
Ensure any burrs are filed or removed and that
any seals are located properly before assembly.
Hold the inner (60mm) pipe of the terminal
assembly and connect to the push-fit end of the
90°bend(supplied)usingatwistingaction.Insert
the assembled flue into the previously drilled
hole. Using the clips & screws supplied, connect
the flue assembly to the boiler, ensuring that the
terminal protrudes past the finished outside wall
by the correct length (135mm).
You must ensure that the entire flue system is
properly supported and connected.
Seal the flue assembly to the wall using cement
orasuitablealternativethatprovidessatisfactory
weatherproofing. The exterior trim can now be
fitted.
EXTENDING THE HORIZONTAL FLUE
If the horizontal flue requires extension/s or
additional bend/s, the horizontal flue terminal kit
(2359029) must be used. Connect the bend -
supplied with the terminal kit - to the top of the
water heater using the clips, screws, & gaskets
supplied.Theadditionalbends&extensionshave
an internal push-fit connection, care should be
taken to ensure that the correct seal is made
when assembling the flue system. Connect the
required number of flue extensions or bends (up
tothemaximumequivalentfluelength)totheflue
terminalusingtheclips,screws &gasketssupplied
(see fig. 7 & 8).
Fig. 7
Max. 833mm
Dimension “X”
135mm
Dimension “Y”
7,5
110
Fig. 8
Extension
Push-fit
connection
Boiler
7,5 mm
IMPORTANT
The flue restrictor ring must be removed or
discardedifthetotalfluelength-includingbends-
exceeds 1.0m.
NOTE
When cutting the horizontal flue terminal or an
extensiontotherequiredlength,youmustensure
that the excess is cut from the plain end of the
terminal or extension, and that the inner (60mm)
pipe is 7,5mm longer than outer (100mm) pipe
(seefig.7&8).Removeanyburrs,andcheckthat
any seals are located properly.
You must ensure that the entire flue system is
properly supported and connected.
Seal the flue assembly to the wall using cement
or a suitable alternative that will provide
satisfactory weatherproofing. The interior and
exterior trim can now be fitted.
4.5.2 CONCENTRIC VERTICAL FLUE
Theverticalflueterminalcanbeconnecteddirectly
to the appliance flue outlet.
Alternatively, an extension or bend can be
connected to the appliance flue outlet if desired
(see4.4.2),howeverifadditionalbendsarefitted,
a reduction must be made to the maximum flue
length (see table below).
Using the dimensions given in fig. 9 as a
reference, mark and cut a 105mm hole in the
ceiling and/or roof.
Fit the appropriate flashing plate to the roof
andinserttheverticalflue terminal through the
flashing plate from the outside, ensuring that
the collar on the flue terminal fits over the
flashing.
The fixing holes for the wall-mounting bracket
shouldnowbedrilledandplugged,anappropriate
type and quantity of fixing should be used to
ensure that the bracket is mounted securely.
Once the bracket has been secured to the wall,
mount the appliance onto the bracket.
Reductionin maximum fluelength foreachbend
Reduction for bends
Bend
45°bend 0,5 metre
90°bend 1,0 metre
Vertical flue terminal and accessories
Part No. Description Length
2359039
0225770
0225765
2359069
2359079
2359049
2359059
0225760
Vertical flue terminal
Pitched roof flashing plate
Flat roof flashing plate
750mm extension
1500mm extension
45°bend (pair)
90°bend
Wall bracket (5)
1000 mm
N/A
N/A
750mm
1500mm
N/A
N/A
N/A

8
Fig. 9 Twin flue accessories
Part No. Description Length
0225805
0225810
300
0225770
0225765
0225815
0225820
0225825
0225830
0225835
0225840
0225845
0225850
0225855
Horizontal flue terminal
Vertical flue terminal
Concentric to twin, adapter
Pitched roof flashing plate
Flat roof flashing plate
Condensate drain kit
0,25m extension (pair)
0,5m extension (pair)
1,0m extension (pair)
2,0m extension (pair)
45°bend (pair)
90°bend (pair)
Twin bracket (5)
Single bracket (5)
1000 mm
1000 mm
N/A
N/A
N/A
N/A
250mm
500mm
1000mm
2000mm
N/A
N/A
N/A
N/A
166mm
465mm
300mm minimum
The vertical flue terminal is 1.0 metre in length
andcannotbecut; thereforeitmaybenecessary
toadjust the heightoftheappliance tosuitoruse
a suitable extension.
Removeordiscardthefluerestrictorringfromthe
appliance flue outlet (see fig. 1), if the total flue
length-includingtheallowanceforanyadditional
bends - exceeds 1.0 metre.
Connect the vertical flue assembly to the water
heaterfluespigotusing the 60mm & 100mm clips,
gaskets & screws (supplied), ensuring the correct
seal is made. The flue support bracket (supplied
with the vertical flue kit) can now be fitted.
Iftheverticalfluerequiresextension/soradditional
bend/s, connect the required number of flue
extensions or bends (up to the maximum
equivalent flue length) between the water heater
and vertical flue assembly (see fig. 8).
NOTE
Whencuttinganextensiontotherequiredlength,
you must ensure that the excess is cut from the
plain end of the extension and that the inner
(60mm)pipeis7,5mmlongerthanouter(100mm)
pipe (see fig. 8). Remove any burrs, and check
that any seals are located properly.
You must ensure that the entire flue system is
properly supported and connected.
4.5.3 TWIN FLUE SYSTEM
TheVokera twin flue system enables greater flue
distances to be achieved (see 4.4.2) than that of
the standard concentric flue system.
It can be used for horizontal or vertical
applications, however the twin flue system must
be converted to the dedicated concentric flue kit
fortermination.
It is essential that the installation of the twin flue
system be carried out in strict accordance with
these instructions.
GUIDANCE NOTES ON TWIN FLUE
INSTALLATION
●The flue must have a fall back of 1°back to the
appliancetoallowanycondensatethatmayform
in the flue system to drain via the condensate
drain. Consideration must also be given to the
factthat thereisthepossibilityofasmallamount
of condensate dripping from the terminal.
●Ensurethatthe entire fluesystemisadequately
supported, use at least one bracket for each
extension.
●The entire flue system must be adequately
insulatedto maintainheatwithinthe fluesystem
thereby reducing the possibility of condensate
production.
●As the exhaust outlet pipe can reach very high
temperatures it must be protected to prevent
persons touching the hot surface.
●Thecondensatedrain pipe must be connected
in accordance with building regulations.
MOUNTING THE WATER HEATER
The fixing holes for the wall-mounting bracket
should now be drilled and plugged, an
appropriate type and quantity of fixing should be
used to ensure that the bracket is mounted
securely. Once the bracket has been secured to
the wall, mount the appliance onto the bracket.
4.5.3.1 INSTALLATION OF CONCENTRIC TO TWIN
ADAPTOR KIT (see fig. 10)
●Remove the flue restrictor ring from the
appliance flue outlet (if fitted).
●Using the two holes in the concentric section
of the adaptor as a guide, drill two - 3mm -
corresponding holes on the appliance flue
outlet.
●Fit the adaptor to the appliance flue outlet and
secure it using the screws provided.
Reductionin maximum fluelength foreachbend
Reduction for bends
Bend
45°bend
90°bend 1,0 metre
1,0 metre

9
Fig. 10
Fig. 11
Condensate drain kit
4.5.3.2 INSTALLATION OF CONDENSATE DRAIN KIT
(see fig. 11)
The condensate drain kit must be fitted within 1
metre of the appliance flue outlet. It is
recommended that the condensate drain kit
should be fitted in the vertical plane, however it
can be fitted horizontally with care.
●Fit the first bend to the condensate drain kit or
exhaust connection manifold by firmly pushing
in to position.
●Using the two holes in the exhaust connection
manifold as a guide, drill a 3mm hole in each
and secure using the screws provided.
●Connect the air inlet pipe to the air baffle as
above.
●Thetwinflue pipes extensions and accessories
can now be installed by pushing together (the
plain end of each extension or bend should be
pushed approximately 50mm into the female
socket of the previous piece).
4.5.3.3 HORIZONTAL TERMINATION (see fig. 12)
The twin flue system must be converted to the
dedicated concentric flue kit for termination.
●The horizontal terminal is supplied with a built-
in converter box and cannot be shortened.
●A 130mm hole is required for the passage of
the concentric terminal through the wall.
●The air inlet pipe must always be level with or
below, that of the exhaust pipe.
Dependingonsite conditions itmaybepreferable
to install the terminal assembly prior to fitting the
twin flue pipes.
Mark and drill a 130mm hole for the passage of
the horizontal flue terminal, ensuring that there
is a 1°fall back to the water heater (17mm per
1000mm). Insert the terminal assembly into the
flue hole.
Push-fitthe twin flue pipesonto the concentric to
twinconverterboxensuring that the exhaust pipe
connects to the exhaust connection on the
concentric to twin converter.
If necessary cut the plain ends (male) of the twin
flue pipes to allow connection to the concentric
to twin converter.
NOTE
●Before cutting twin flue pipes ensure
allowances have been made for connection
ontotheprevious piece and ontotheconcentric
to twin converter. The last twin flue pipes must
be pushed 50mm onto the male spigots of the
concentric to twin converter.
●You must ensure that the entire flue system is
properly supported and connected.
●Sealthe flueterminalassemblyto thewallusing
cementora suitable alternative thatwillprovide
satisfactory weatherproofing. The interior and
exterior trim can now be fitted.
4.5.3.4 VERTICAL TERMINATION (see fig. 13)
The twin flue system must be converted to the
dedicated concentric flue kit for termination.
●The vertical terminal is supplied with a built-in
converter box and cannot be shortened.
●A130mm hole is required for the passage of
the concentric terminal through the ceiling
and/or roof.
Dependingonsite conditions itmaybepreferable
to install the terminal assembly prior to fitting the
twin flue pipes.
Fit the appropriate flashing plate to the roof
and insert the vertical flue terminal through the
flashing plate from the outside, ensuring that
the collar on the flue terminal fits over the
flashing.
Push-fitthe twin flue pipesonto the concentric to
twin converter ensuring that the exhaust pipe
connects to the exhaust connection on the
concentric to twin converter.
If necessary cut the plain ends (male) of the twin
flue pipes to allow connection to the concentric
to twin converter.
NOTE
●Before cutting twin flue pipes ensure
allowances have been made for connection
onto the previous piece and onto the
concentric to twin converter. The last twin flue
pipes must be pushed 50mm onto the male
spigots of the concentric to twin converter.
●You must ensure that the entire flue system is
properly supported and connected.
●Ensure that any horizontal sections of pipe
have a 1°fall towards the appliance (17mm
per 1000mm).

10
Fig. 12
Fig. 13
Fig.14
Convertor box
Condensate trap
4.6 CONNECTING THE GAS AND WATER
The appliance is supplied with an accessories
pack that contains sealing washers and service
valves.Theservicevalvesareofthecompression
type.When connecting pipe work to the valves,
tighten the compression end first, then insert the
sealingwashersbeforetighteningthevalvetothe
appliance.
NOTE
It will be necessary to hold the valve with one
spanner whilst tightening with another.
4.6.1 GAS (see fig. 4)
The appliance is supplied with a 15mm service
valve, connect a 15mm pipe to the inlet of the
valve and tighten both nuts.
NOTE
It will be necessary to calculate the diameter of
the gas supply pipe to ensure the appliance has
an adequate supply of gas.
4.6.2 COLD INLET (see fig. 4)
Theappliance is supplied with 15mm stopcock for
the cold water inlet connection, connect a 15mm
pipe to the inlet of the valve and tighten the nut.
4.6.3 HOT WATER OUTLET (see fig. 4)
The appliance is supplied with 15mm connector
for the hot water outlet connection, connect a
15mm pipe to the outlet of the connector and
tighten the nut.
4.7 ELECTRICAL CONNECTIONS
Theelectrical supply must be as specified in 3.7.
The appliance is supplied, pre-wired with a 0,9
metrelengthofflex,connectthewiresasfollows:
●connect the Brown wire to the L (Live) terminal
of the plug or fused isolator;
●connecttheBluewiretotheN(Neutral)terminal
of the plug or fused isolator;
●connecttheGreen/Yellow wire to the E (Earth)
terminal of the plug or isolator;
●ensure the plug or fused isolator is fitted with a
3-amp fuse.
4.7.1 CASING REMOVAL
To gain internal access to the appliance you must
firstremovethecasing,proceedasoutlinedbelow:
●locate and remove the 4 screws that secure the
controlsfasciatotheappliancecasing(seefig.14);
●lift the casing upward to disengage it from the
top locating hooks and then remove;
●gently lower the control fascia until it rests;
●storethecasingandscrewssafelyuntilrequired.
Re-fit in the reverse order.
Fig.15
Screws
Screws
Outlet test
nipple
Inlet test
nipple Protective
cap

11
5.1 GAS SUPPLY INSTALLATION
Inspect the entire installation including the gas
meter,testforsoundnessandpurge.RefertoBS
6891 for specific instruction.
5.2 WATER PIPE WORK
The water pipe work shall be flushed and tested
in accordance with the Water Supply (water
fittings) Regulations (Water Byelaws Scotland).
5.3 PRE-OPERATION CHECKS
Before attempting the initial lighting of the appli-
ance, the following checks must be carried out:
●ensureall gas service valves fromthe meter to
theapplianceareopenandthesupplypipehas
been properly purged;
●ensure the proper electrical checks have been
carried out (see 7.7), particularly continuity,
polarity and resistance to earth;
●ensure the 3 amp fuse – supplied with the
appliance – has been fitted;
●ensuretheapplianceandassociatedpipework
has been filled and vented;
●ensurethefluesystemhasbeenfittedproperly
and in accordance with the instructions;
●ensure all appliance service valves are open.
5.4 INITIAL LIGHTING
Ensure the electrical supply to the appliance is
switched on. Turn the selector knob to the ‘on’
position(fig.1).Openahotwateroutlet(preferably
a bath tap) and ensure the flow rate exceeds 2
litres per minute.
The appliance will now go through an ignition
sequence as described in 1.2. Should the
appliancefailtoignite,referto5.3and/orsection
7 (fault finding).
5.5 CHECKING THE BURNER PRESSURE
Although the burner pressure is factory set, it is
necessary to check it during commissioning.
Isolate the appliance from the electrical supply
andattachasuitablemanometertothegasvalve
outlettestnipple(seefig.15).Lighttheappliance
as described in 5.4 and compare the reading on
the manometer with the values described in 2.2.
If adjustement is required, follow the detailed
instructions in section 7 (7.3).
Once the burner pressure has been checked,
isolate the appliance from the electrical supply,
remove the manometer, and tighten the gas
valve outlet test nipple.
5.6 SETTING THE OUTLET TEMPERATURE
Thehotwateroutlettemperaturecanbeadjusted
between 40°C - 65°C via the thermostat knob
(see fig. 1).
5.7 FINAL CHECKS
●ENSURE ALL TEST NIPPLES ON THE AP-
PLIANCE GAS VALVE HAVE BEEN
TIGHTENED AND CHECKED FOR
SOUNDNESS.
●ENSURETHEAPPLIANCEFLUESYSTEMIS
FITTED CORRECTLY AND IS PROPERLY
SECURED.
●ENSURE ALL PIPE WORK IS RE-CHECKED
FOR SOUNDNESS.
●RE-FIT APPLIANCE CASING.
Completedetailsoftheinstallationinthewarranty
card supplied with the appliance. This is an
important document, which must be correctly
completed and handed to the user. Failure to
installandcommissiontheappliancetothemanu-
facturersinstructionsmayinvalidatethewarranty.
5.8 INSTRUCTING THE USER
Hand over all documentation supplied with this
appliance – including these instructions – and
explainthe importance of keepingthem in a safe
place.
Explain to the user how to isolate the appliance
from the gas, water and electricity supplies, and
the locations of all drain points.
Show the user how to operate the appliance and
its controls correctly.
Explain to the user how to turn off the appliance
forbothlongandshortperiods,andadviseonthe
necessary precautions to prevent frost damage.
Explain to the user that for continued safe and
efficientoperation,theappliancemustbeserviced
annually by a competent person.
SECTION 5 COMMISSIONING

12
SECTION 6 SERVICING
6.1 GENERAL
Toensurethecontinuedsafeandefficientopera-
tion of the appliance, it is recommended that it is
checked and serviced at regular intervals.
The frequency of servicing will depend upon the
particular installation conditions, but in general,
once per year should be adequate.
It is the law that any servicing work is carried out
bycompetentpersonsuchasaVokeraengineer,
an approved service agent, British Gas, or other
CORGI registered personnel.
Thefollowinginstructionsapplyto the appliance,
but it should be remembered that the domestic
hot water system will also require attention from
time to time.
6.2 ROUTINE ANNUAL SERVICING
●Checktheoperationoftheapplianceand ensure
it functions as described in section 7.
●Compare the performance of the appliance
with its design specification. The cause of any
noticeable deterioration should be identified
and rectified without delay.
●Thoroughly inspect the appliance for signs of
damage or deterioration especially the flue
system and the electrical apparatus.
●Check and adjust – if necessary – all burner
pressure settings (see 7.3).
●Carry out an analysis of the flue gases (see
7.4), and visually check the condition of the
entire flue assembly.
●Compare the results with the appliance design
specification.Anydeteriorationinperformance
must be identified and rectified without delay.
●Ensure both flue venturis are clean and free
from any debris or obstruction.
●Ensureboththeburnerandheatexchangerare
clean and free from any debris or obstruction.
●Inspectalljointsforsignsofleakageandrepair
if necessary.
●Refer to the commissioning section and/or re-
placement of parts section for detailed
instruction if required.
6.3 REPLACEMENT OF COMPONENTS
Although it is anticipated that this appliance will
giveyearsofreliable,troublefreeservice,thelife
spanofcomponentswillbedeterminedbyfactors
such as operating conditions and usage. Should
the appliance develop a fault, the fault finding
sectionwillassistindeterminingwhichcomponent
is malfunctioning.
6.4 COMPONENT REMOVAL PROCEDURE
Toremoveacomponent,accesstotheinteriorof
the appliance is essential. Isolate the appliance
from the electrical supply and remove the fuse.
And when necessary, close all service valves on
the appliance, remove the appliance casing as
describedinsection4.7.1,drainthewatercontent
from the appliance via an outlet or appropriate
drainpoint.Ensure some waterabsorbentcloths
areavailabletocatchanyresidualwaterthatmay
drip from the appliance or removed component.
Undertake a complete commissioning check as
detailed in section 5, after replacing any
component. ALWAYS TEST FOR GAS
SOUNDNESS IF ANY GAS CARRYING
COMPONENTS HAVE BEEN REMOVED OR
DISTURBED.
6.5 NTC THERMISTORS (see fig. 1)
Carry out component removal procedure as de-
scribed in 6.4.
Locate and remove the ten screws that secure
the air chamber cover.
Remove the air chamber cover.
Disconnect thermistor electrical plug. Using a
13mmspannerslackenandremovethethermistor
andsealingwasher.Replaceinthereverseorder.
6.6 HIGH LIMIT THERMOSTAT (see fig. 1)
Carry out component removal procedure as de-
scribed in 6.4.
Locate and remove the ten screws that secure
the air chamber cover. Remove the air chamber
cover.
Pull off electrical connections from the high limit
thermostat,slackenandremoveretainingscrews.
Replace in the reverse order.
6.7 FLOW SWITCH (see fig. 16)
Carry out component removal procedure as de-
scribed in 6.4.
Remove the appliance casing as described in
4.7.1. Disconnect the cold water inlet pipe from
the bottom connection of the flow switch.
Disconnecttheoutletpipefromthetopconnection
of the flow switch. Detach the electrical plug/
wires from the flow switch. Slacken and remove
the lock-nut that secures the flow switch to the
lower frame. Replace in the reverse order.
Fig. 16
3
4
5
7
1
2
6
5
1 Screws
2 High limit thermostat
3 Outlet pipe
4 DHW flow switch
5 Locknut
6 Gas valve securing screws
7 Gas valve

13
6.7.1 PRINTEDCIRCUIT BOARD(PCB) (see fig.17)
Carry out component removal procedure as de-
scribed in 6.4.
Remove the appliance casing as described in
4.7.1. Carefully slide out the control panel until
the lugs on the lower right and left side of the
panel are free from the slots on the appliance
frame.Removetheelectrodeleadfromitsclipon
the PCB housing. Locate and remove the two
screws which secure the PCB cover & terminal
cover, then remove cover, after carefully taking
note of all wiring connections, disconnect all
wiringfromthePCB, locateandremovethePCB
securing screws, remove PCB.
Replace in the reverse order.
NOTE
EnsurethatthereplacementPCBhasthecorrect
“Jumper Tag” configuration (see section 8).
6.8 GAS VALVE (see fig. 16)
Carry out component removal procedure as de-
scribed in 6.4. Remove the appliance casing as
described in 4.7.1.
Thegasvalvemustbechangedascompleteunit.
Disconnectthe electricalplugand leadsfromthe
gas valve. Disconnect compensator tube from
gas valve regulator. Slacken and unscrew gas
valve inlet and outlet connections. Please note,
the sealing washers must be discarded and re-
placed with new sealing washers. Locate and
remove gas valve retaining screws on the
underside of the appliance. The gas valve can
now be removed. Replace in the reverse order.
Check and adjust burner pressure settings.
WARNING, A GAS SOUNDNESS CHECK
MUST BE CARRIED OUT.
6.9 BURNER, INJECTORS AND SPARK/SENSE
ELECTRODE (see fig. 18a,b,c)
Carry out component removal procedure as de-
scribed in 6.4. Remove the appliance casing as
described in 4.7.1.
Locate and remove the ten screws that secure
the air chamber cover. Remove the air chamber
cover.Locateandremove the 5 screws securing
the front combustion cover and retaining plate,
pull the cover towards you before lowering and
disengaging.
Disconnecttheelectrodeleadfromitsconnector.
Disconnect the gas valve outlet pipe from its
connection to the burner. Slacken and remove
the lock-nut that secures the burner assembly to
the air chamber base. The burner can now be
removed. With the burner assembly removed,
slackenandremovetheburnerbarretainingclips
in order to gain access to the injectors. Replace
in the reverse order. Please note, the injector
sealingwashers mustbereplaced iftheinjectors
havebeen removed, ensureallsealsare in good
condition,takingcaretoensuretheyarereplaced
correctly.
6.10 FLUE FAN (see fig. 19)
Carry out component removal procedure as
described in 6.4. Remove the appliance casing
as described in 4.7.1.
Locate and remove the 10 screws that secure the
airchambercover.Removetheairchambercover.
Locate and remove the 4 screws that secure the
flue assembly. Disconnect the electrical
connections and silicone tubes attached to the
fan, noting their positions. Disconnect the
maintainenceclipthatsecurestheflueoutletpipe
tothefan,easethefan&fluehoodassemblyfrom
its location. Locate and remove the screws that
secure the fan to the flue hood. Remove the fan
Fig. 17
Fig. 18a
Fig. 18b
Fig. 18c

14
7.1 CHECKING APPLIANCE OPERATION
Whencarrying out any repairs or servicing to the
appliance,therelevantcommissioningprocedure
mustbeundertakentoensurethecontinuedsafe
operation of the appliance. Particular attention
shouldbe madetoensure gassoundness,water
soundness, and the electrical integrity of the
appliance.
7.2 APPLIANCE MODE OF OPERATION
When there is a request for hot water via a hot
water outlet or tap, the water flow switch senses
water movement thereby energising the fan.
NOTE
Theremustbesufficientinletwaterpressureand
flow (min. 0,15 bar/ 2 lpm) to ensure the water
flow switch is activated. If there is insufficient
pressure and/or flow, the appliance will be
prevented from operating. When the fan runs, it
proves the differential air pressure switch which
in-turn allows an ignition sequence to begin.
NOTE
The ignition sequence lasts approximately 7
seconds,duringwhichtheappliancewillcontinue
to spark even if the burner has already lit. If the
spark/sensing electrode does not sense ignition
the appliance will then go to lockout. Ignition is
sensedbytheelectroniccircuitrytoensureflame
stability at the burner. Once successful ignition
hasbeenachieved,theelectroniccircuitryallows
the full gas rate through the appliance.
When the appliance reaches the desired
temperaturetheburner will modulatetomaintain
the set temperature. Should the temperature
continue to rise the burner will shut off when the
maximum operating temperature is attained.
When the request for heat and/or hot water has
beensatisfied,thefanmaycontinuetooperateto
dissipate any residual heat within the appliance.
7.3 CHECKING AND ADJUSTING BURNER
PRESSURE (see fig. 17)
Altough the burner pressure is factory set, it is
necessarytocheckitduringservicingorifthegas
valve has been removed. Isolate the appliance
from the electrical supply and attach a suitable
manometer to the gas valve outlet test nipple.
Remove the compensator tube.
7.3.1 SETTING THE MAXIMUM BURNER PRESSURE
Light the appliance as described in 5.6 and
compare the reading on the manometer with the
valuedescribedin2.2.Ifadjustementisrequired,
remove the protective cap from the gas valve
modulating coil assembly and turn the outer
(10mm) nut clockwise to increase, or counter-
clockwise to decrease the burner pressure.
to flue elbow. Replace in the reverse order.
Ensureallsealsareingoodcondition,takingcare
to ensure they are replaced correctly.
6.11 HEAT EXCHANGER (see fig. 20)
Carry out component removal procedure as
described in 6.4. Remove the appliance casing
as described in 4.7.1.
Locateandremovethe10screwsthatsecurethe
air chamber cover. Remove the air chamber
cover.Locateandremove the 5 screws securing
the front combustion cover and retaining plate.
Disconnect the inlet and outlet connections on
the heat exchanger. The heat exchanger can
now be withdrawn from the appliance (if
necessary, the burner should be removed to
facilitate access to the connections). Replace in
the reverse order. Ensure all seals are in good
condition,takingcaretoensuretheyarereplaced
correctly.
Fig. 19
6.12 AIR PRESSURE SWITCH (see fig. 1)
Carry out component removal procedure as
described in 6.4. Remove the appliance casing
as described in 4.7.1.
Locateandremovethe10screwsthatsecurethe
air chamber cover. Remove the air chamber
cover.Locateandremovethetwoscrewsholding
the air pressure switch to the air chamber.
Disconnecttheelectricalconnectionsandsilicone
tubes attached to the air pressure switch, noting
their positions. Replace in the reverse order.
Ensureallsealsareingoodcondition,takingcare
to ensure they are replaced correctly.
Fig. 20
SECTION 7 CHECKS, ADJUSTMENTS, AND FAULT FINDING

15
NOTE
You should ensure that one or two hot water
outletsarefullyopenduringtheaboveprocedure.
This will ensure that the output of the appliance
(burner pressure) is not compromised due to a
high outlet temperature.
7.3.2 SETTINGTHEMINIMUMBURNERPRESSURE
Once the maximum burner pressure has been
checkedand/oradjusted,removeoneofthegrey
wires from the modulating coil. Compare the
reading on the manometer with the value
described in 2.2. If adjustement is required, turn
the inner (red) cross-head screw clockwise to
increase, or counter-clockwise to decrease the
burner pressure, whilst ensuring that the outer
(10mm)nut doesnotmove. Whencheckingand/
or adjustement has been completed, isolate the
appliance from the electrical supply, replace the
protective cap, refit the compensator tube, refit
the grey wire to the modulating coil, remove the
manometer, and tighten the outlet test nipple.
IMPORTANT: A GAS SOUNDNESS CHECK
MUST BE CARRIED OUT.
7.4 EXTERNAL FAULTS
Beforecarryingoutanyfault-findingorcomponent
replacement,ensurethefaultisnotattributableto
any aspect of the installation.
7.4.1 INSTALLATION FAULTS
7.5 ELECTRICAL CHECKS
Any electrical checks must be carried out by a
suitably qualified person.
7.5.1 EARTH CONTINUITY TEST
Isolate the appliance from the electrical supply,
and using a suitable multi-meter carry out a
resistance test. Connect test leads between an
appliance earth point and the earth wire of the
appliance supply cable. The resistance should
be less than 1 ohm. If the resistance is greater
than 1 ohm check all earth wires and connectors
for continuity and integrity.
7.5.2 SHORT CIRCUIT CHECK
Isolate the appliance from the electrical supply,
andusingasuitablemulti-meter,carryoutashort
circuittestbetweentheLive&Neutralconnections
at the appliance.
RepeatabovetestontheLive&Earthconnections
at the appliance term.
NOTE
Should it be found that the fuse has failed but no
fault is indicated, a detailed continuity.
Check will be required to trace the fault. A visual
inspection of components may also assist in
locating the fault.
7.5.3 POLARITY CHECK
With the appliance connected to the electrical
supplyandusingasuitablemulti-meter,carryout
the following voltage tests:
●connect test leads between the Live & Neutral
connectionsattheappliance.Themetershould
read approximately 230V ac. If so proceed to
next stage. If not, see 7.5.4.
●connect test leads between the Live & Earth
connectionsattheappliance.Themetershould
read approximately 230V ac. If so proceed to
next stage. If not, see 7.5.4.
●ConnecttestleadsbetweentheNeutral&Earth
connectionsattheappliance.Themetershould
read approximately 0 – 15Vac. If so polarity is
correct. If not, see 7.5.4.
7.5.4 REVERSED POLARITY OR SUPPLY FAULT
Repeat the above tests at the appliance isolator,
iftesting reveals correct polarity and/orsupply at
the isolator, re-check wiring and connections
between the isolator and the appliance.
Iftestsontheisolatoralsorevealreversedpolarity
or a supply fault, consult the local electricity
supplier for advice.
7.5.5 RESISTANCE TO EARTH CHECK
Isolate the appliance from the electrical supply,
and using a suitable multi-meter carry out a
resistance test. Connect test leads between the
Live & Earth connections at the appliance. If the
meterreads otherthaninfinity thereisafault that
must be isolated, carry out a detailed continuity
check to identify the location of the fault.
IMPORTANT
These series of checks must be carried out
before attempting any fault-finding procedures
ontheappliance. On completion of any taskthat
required the disconnection and re-connection of
anyelectricalwiringorcomponent,these checks
must be repeated.
7.6 FAULT FINDING
Beforeattemptingany fault-finding, the electrical
checks as detailed in 7.5 must be carried out.
Isolate the appliance from the electrical supply
and remove the casing and PCB cover.
Restore the electrical supply to the appliance,
turn the selector switch to the “on” position, and
open a hot water outlet. The appliance should
now function as described in section 7.2. Should
the appliance fail to respond, the internal fuse
and connectors should be checked to ensure
Symptom Possible causes
No ignition
Poor hot water
Unstableflame
picture
Check external wiring.
Checkcold supplyisconnectedtocold
inlet.
Check gas supply.
Check adjust flow rate.
Check flue system

16
integrity and continuity. If the appliance still fails
to respond, refer to the detailed fault-finding
flowchartsoverleaf.
Green LED
On for 1 second, off for 5
seconds
On
Off
On
Flashing on/off every 0,5
seconds
Flashing on/off every 0,5
seconds
Red LED Action required
Status
Off
Off
On
Flashing on/off every 0,5
seconds
Off
Flashing on/off every 0,5
seconds
Switched off or at stand-by
DHW request
Flame lockout
Overheating
Air pressure switch “open”
NTC thermistor fault
NONE
NONE
Check gas supply, check
ignition sequence
Allow to cool, check
operation of appliance
Check flue system, check
air pressure switch and/on
fan
Check NTC thermistor
7.7 FAULT CODES

17
FAULT FINDING TEST ‘1’
NO
MAINS
ON FAN
REPLACE FAN
YES
NO
YES
A
CHECK &/OR
REPLACE
WIRING AND
CONNECTIONS
FAN
RUNNING
START
REPLACE
DRIVER BOARD
NO
NO YES
SWITCH ON WATER
HEATER AND SELECT
WATER TEMPERATURE
AT MAX.
TURN ON TAP WITH
A FLOW RATE >
THAN 2.5 LIT/MIN
MAINS
PRESENT BETWEEN
TERMINALS 8 & 9
ON ACF
MAINS
PRESENT BETWEEN
TERMINALS 10 & 11
ON ACF MAINS
PRESENT
BETWEEN TERMINALS
X1.5 & X1.6 ON
DRIVER
BOARD
CHECK &/OR
REPLACE
WIRING AND
CONNECTIONS
MAINS
PRESENT
BETWEEN TERMINALS
X1.1 & X1.8 ON
DRIVER
BOARD
YES
MAINS
PRESENT
BETWEEN TERMINALS
X1.1 & X1.9 ON
DRIVER
BOARD
CHECK WIRING AND
CONNECTIONS OR
SAFETY THERMOSTAT
MAINS
PRESENT
BETWEEN TERMINALS
X1.1 & X1.2 ON
DRIVER
BOARD
NO
REPLACE
DRIVER BOARD
FUSES OK
CHECK FUSES
F1 & F2 ON
DRIVER BOARD
RESTART THE
TEST
REPLACE FUSES
YES
YES
CHECK &/OR REPALCE
FUSE F3, MAIN SWITCH AND
SUPPLY & CONNECTORS
TO BOILER TERMINALS
CHECK WIRING
BETWEEN MAIN
SWITCH AND DRIVER
BOARD
NO
LINE
LAMP
LIGHT?
MAINS
PRESENT BETWEEN
TERMINALS 7 & 11
ON ACF
A1
MAINS
PRESENT BETWEEN
TERMINALS 4 & 11
ON ACF
REPLACE ACF
BOARD
MAINS
PRESENT
BETWEEN TERMINALS
X1.1 & X1.2 ON
DRIVER
BOARD CHECK &/OR
REPLACE
WIRING AND
CONNECTIONS
YES
CHECK &/OR REPALCE
FUSE F3 MAIN SWITCH
AND SUPPLY &
CONNECTORS TO
BOILER TERMINALS
CHECK WIRING
BETWEEN MAIN
SWITCH AND
DRIVER BOARD
LINE
LAMP
LIGHT?
NO
NO
NO
NO
YES
YES
YES
YES
YES
YES
YES
NO
NO
NO
NO

18
FAULT FINDING TEST ‘2’
YES
YES
NO
NO
A.C.F. OK
NO
YES
NO
NO
YES
YES
YES
NO
IS
THERE
VOLTAGE AT
SPARK ELECTRODE PIN?
ATTENTION !!
VOLTAGE
> 10 kV
A
REPLACE
SENSING
ELECTRODE
AND LEAD
SENSING
ELECTRODE
AND LEAD
OK
CHEK SENSING
ELECTRODE
AND LEAD
MODULATION
TEST
LOCKOUT
AFTER
IGNITION
REPLACE EVG
CHECK GAS
IGNITION
SPARK AT
ELECTRODE
CHECK SPARK
ELECTRODE AND
LEAD
IS
THERE MECHANICAL
OPENING OF GAS VALVE
SOLENOIDS
NO
REPLACE A.C.F.
BOARD
NO
DO THE
AIR FLOW SWTCH
TURN ON
CHECK WIRING AND
CONNECTIONS AND
AIR FLOW SWITCH
YES
NO
ARE THE
VENTURI TUBE
AND THE SILICONE
AIR TUBES
CLEAN
CHECK/CLEAN THE
VENTURI TUBE AND
SILICONE AIR
TUBES
IS
THE AIR DP >
11 mmCH2O
CHECK THE FAN
AND/OR FLUE
GAS TUBE
CHECK
REPLACE AIR
FLOW SWITCH
NO
YES
YES
YES
A2
IS
THERE A GAS
INPUT PRESSURE
GREATHER THAN
13.7 mBAR
REPLACE EVG
MAINS
PRESENT BETWEEN
TERMINALS 6 & 11
ON ACF
REPLACE A.C.F.
BOARD
NO
NO
YES
YES