VOKERA Eclipse ESC Installation & Servicing Instructions Manual

Supplied By www.heating spares.co Tel. [phone]

ESC

Installation
& Servicing
Instructions

THESE INSTRUCTIONS
TO BE RETAINED
BY USER

Supplied By www.heating spares.co Tel. [phone]

Contents

Design principles & operating sequence Page

1.1 Principle components 2

1.2 Mode of operation (at rest) 2

1.3 Domestic hot water mode 2

1.4 Central heating mode 2

1.5 Safety devices 2

Technical data Page

2.1 Central heating 3

2.2 Domestic hot water 3

2.3 Gas pressure 3

2.4 Expansion vessel 3

2.5 Dimensions 3

2.6 Clearances 3

2.7 Connections 3

2.8 Electrical 3

2.9 Flue details 3

2.10 Efficiency 3

2.11 Parameter defaults 4

2.12 Emissions 4

2.13 Pump duty 4

General requirements Page

3.1 Related documents 5

3.2 Location of appliance 5

3.3 Gas supply 5

3.4 Flue system 5

3.5 Air supply 6

3.6 Water circulation 6

3.7 Electrical supply 7

3.8 Showers 7

3.9 Mounting on a combustible surface 7

3.10 Timber framed buildings 7

3.11 Condensate disposal 7

3.12 Inhibitors 7

Installation Page

4.1 Delivery 7

4.2 Contents 7

4.3 Unpacking 7

4.4 Preparation for mounting the appliance 7

4.5 Fitting the flue 8

4.6 Connecting the gas & water 11

4.7 Condensate outlet 12

4.8 Electrical connections 12

Commissioning Page

5.1 Gas supply installation 14

5.2 The heating system 14

5.3 Initial filling of the system 14

5.4 Initial flushing of the system 14

5.5 Filling the hot water system 14

5.6 Pre-operation checks 14

5.7 Initial lighting 14

5.8 Final flushing of the heating system 14

5.9 Operating parameters 14

5.10 Functional parameters 15

5.11 Range rating 15

5.12 Setting the system design pressure 15

5.13 Regulating the central heating system 16

5.14 Final checks 16

5.15 Instructing the user 16

Servicing Page

6.1 General 17

6.2 Routine annual servicing 17

6.3 Replacement of components 17

6.4 Component removal procedure 17

6.5 Pump head removal 17

6.6 Safety valve removal 17

6.7 Automatic air valve removal 17

6.8 Pressure gauge removal 18

6.9 Temperature sensor removal 18

6.10 Main PCB removal 18

6.11 Gas valve removal 18

6.12 Fan removal 19

6.13 Burner removal 19

6.14 Electrode removal 19

6.15 Injector removal 19

6.16 DHW heat exchanger removal 20

6.17 Motorised valve actuator removal 20

6.18 Divertor valve assembly removal 20

6.19 Condense trap removal 20

6.20 Condense pressure switch removal 20

6.21 Combustion cover removal 20

6.22 Expansion vessel removal 21

6.23 Input & status PCB removal 21

Checks, adjustments, and fault finding Page

7.1 Checking appliance operation 22

7.2 Mode of operation 22

7.3 Checking/adjusting fan speeds 22

7.4 Adjusting the gas valve 23

7.5 Status code 24

7.6 Lockout faults codes 25

7.7 Diagnostic recall 25

7.8 Temperature sensor viewing mode 26

7.9 Checking the expansion vessel 26

7.10 External faults (installation) 26

7.11 Electrical checks 26

7.12 Fault finding 27

Wiring diagrams Page

8.1 Important note 31

8.2 Installation of Vokera time clock 31

8.3 External controls 31

Exploded diagrams Page

9.1 Table 1 35

9.2 Table 2 36

9.3 Table 3 37

9.4 Table 4 38

9.5 Table 5 39

9.6 Table 6 40

L.P.G. instructions Page

10.1 Technical data 41

10.2 Related documents 41

10.3 Gas supply 41

10.4 Gas supply installation 41

10.5 Adjusting the gas valve 41

10.6 Range rating 41

Supplied By www.heating spares.co Tel. [phone]

INTRODUCTION

The Vokera Eclipse ESC is a combined central heating
and domestic hot water condensing boiler, which – by
design – incorporates full sequence electronic ignition,
circulating pump, expansion vessel, safety valve, pressure
gauge, and automatic by-pass.

The Eclipse is produced as a room sealed, category C1,
C3, C6 appliance, suitable for wall mounting applications
only. The Eclipse is provided with a fan powered flue

outlet with an annular co-axial combustion air intake that
can be rotated – horizontally – through 360 degrees for
various horizontal or vertical applications. The Eclipse
can also be used with the Vokera twin flue system.
These appliances are designed for use with sealed
systems only; consequently they are not intended for use
on open vented systems.

A range rating facility is incorporated in the appliance.

General layout

1 Auto air vent
2 Flue outlet & air intake
3 Flue gas analysis test point
4 Burner plate
5 Spark/Sensing Electrode
6 Fan assembly
7 Pressure switch
8 Electronic Control Board (PCB)
9 Condense trap
10 Cold water inlet
11 Hot water outlet
12 Gas connection
13 Pressure gauge
14 Time clock aperture
15 Function key pad
16 LED display
17 Reset button
18 Heating flow connection
19 Safety valve
20 Heating return connection
21 Auto by-pass
22 Three port valve actuator
23 Pump
24 Return sensor (NTC2)
25 Gas valve
26 Flow sensor (NTC1)

Fig. 1

1

Supplied By www.heating spares.co Tel. [phone]

SECTION 1 DESIGN PRINCIPLES AND OPERATING SEQUENCE

1.1 PRINCIPLE COMPONENTS

● A fully integrated electronic control board

featuring electronic temperature control,
continuous air/gas modulation, anti-cycle
control, pump over-run, self-diagnostic fault
indicator, electronic ignition with flame
supervision, & appliance frost protection.

● Cast aluminium mono-block heat exchanger.

● Low Nox burner with pre-mix.

● Two-stage gas valve.

● Pump.

● Expansion vessel.

● Pressure gauge.

● Safety valve.

1.2 MODE OF OPERATION (at rest)

When there is no demand for heating or hot
water, the boiler will periodically light to pre-heat
the domestic hot water heat exchanger to
approximately 55°C. This ensures that the
appliance is at operating temperature when there
is a request for domestic hot water. The parameter
for the allowable temperature drop – between pre­heat operation – can be adjusted. If the appliance
remains inactive for a period of 24 hours, the pump
and motorised valve will be energised for a few
moments to prevent these components from
seizing. Should the flow temperature sensor fall
below 7°C the pump will be energised.
If the flow sensor temperature falls to below 3°C
the burner will be lit and the appliance will operate
at the minimum output until the temperature of
the flow sensor reaches 10°C, whereupon the
pump will continue to run in pump over-run mode.

1.3 DOMESTIC HOT WATER MODE

When the appliance is at rest, the motorised
valve is energised to the hot water position, when
a demand for hot water is made the cold water
temperature sensor activates the pump and fan.
When the fan is sensed to be operating correctly,
the ignition sequence commences. The speed of
the fan and therefore the output of the boiler is
determined by the temperature of the water
sensed by the return temperature sensor,
consequently a high temperature at the return
sensor results in a lower fan speed.
As the water temperature increases, the
temperature sensors – located on the flow and
return pipes of the boiler – reduce the fan speed
via the electronic circuitry. Depending on the
load, either the water temperature will continue to
rise until the set point is achieved or the water
temperature will fall whereby fan speed will
increase relative to the output required.

boiler is determined by the temperature of the
water sensed by the flow & return temperature
sensors, consequently a high temperature at the
flow sensor results in a lower fan speed. As the
water temperature increases, the temperature
sensors – located on the flow and return pipes of
the boiler – reduce the fan speed via the electronic
circuitry. Depending on the load, either the water
temperature will continue to rise until the set point
is achieved or the water temperature will fall
whereby fan speed will increase relative to the
output required. When the boiler has reached the
set point, the burner will switch off. The built-in
anti-cycle device prevents the burner from re­lighting for an adjustable period of time (factory
default is 3 minutes). When the temperature of
the flow sensor falls below the set-point, the
burner will re-light.

1.5 SAFETY DEVICES

When the appliance is in use, safe operation is
ensured by:

● a high limit thermostat that interrupts the

operation of the burner;

● a differential temperature protection circuit which

interrupts the burner if the temperature
differential is inverted;

● a fan speed sensor which checks the correct

operation of the fan, thereby allowing safe
operation of the burner;

● a safety valve which releases excess pressure

from the primary circuit;

● a condense pressure switch that will stop the

burner from operating should the condense
trap become blocked.

4

NTC2
(return sensor)

Domestic Heat
Exchanger

1

NTC1 (flow sensor)

Main Heat
Exchanger

Expansion
vessel

NTC 3
(inlet sensor)

1.4 CENTRAL HEATING MODE

When there is a request for heat via the time clock
and/or external controls the motorised valve and
pump will go through a self-test function this is to
ensure correct operation and valve configuration.
Once the self-test function is complete, the pump
and fan will activated via the flow temperature
sensor. When the fan is sensed to be operating
correctly, the ignition sequence commences. The
speed of the fan and therefore the output of the

Fig. 2

2

gas

return flow hw

outlet

cold
inlet

Supplied By www.heating spares.co Tel. [phone]

SECTION 2 TECHNICAL DATA

2.1 Central heating

Heat input 29,00 kW
Maximum heat output 60/80°C (return & flow temperature) 25,3 kW
Maximum heat output 30/50°C (return & flow temperature) 26,8 kW
Minimum heat output 60/80°C (return & flow temperature) 7,3 kW
Minimum heat output 30/50°C (return & flow temperature) 8,10 kW
Minimum working pressure 0,45 bar
Maximum working pressure 3 bar
Minimum flow rate 350 l/h

2.2 Domestic hot water

Maximum input 29,00 kW
Maximum output 25,3 kW
Minimum output 8,1 kW
Flow rate (35°C rise) 10,4 l/min
Maximum inlet pressure 6,0 bar
Minimum inlet pressure to operate 0,15 bar
Minimum flow rate to operate 2,5 l/min.

2.3 Gas pressure Maximum

Inlet pressure (G20) 20,0 mbar
Maximum gas rate 2,76 m3/h
Minimum gas rate 0,80 m3/h
Injector size single injector with six 3,8 mm holes

2.4 Expansion vessel

Capacity 8 litres
Maximum system volume 76 litres
Pre-charge pressure 1,0 bar

2.5 Dimensions

Height 790 mm
Width 450 mm
Depth 322 mm
Dry weight 57 kg

2.6 Clearances

Sides 25 mm
Top
Bottom 150 mm
Front 600 mm

2.7 Connections

Flow & return 22 mm compression
Hot & cold water 15 mm compression
Gas 1/2 inch BSP
Safety valve 1/2 inch BSP

2.8 Electrical

Voltage 230V/~ 50hz
Power consumption 130 W
Internal fuse 2 A
External fuse 3 A

2.9 Flue details

Maximum horizontal flue length (concentric) 6,45 metres
Maximum vertical flue length (concentric) 7,45 metres
Maximum twin flue length (horizontal or vertical) 29 m + 29 m

2.10 Efficiency

SEBDUK rating Band “A”

150 mm from casing or 25mm above flue elbow (whichever is applicable)

Ref. Condition 15 °C , 1013,25 mbar, dry gas
NOTE: L.P.G. data refer to section 10

3

Supplied By www.heating spares.co Tel. [phone]

2.11 Adjustable operating parameters
PARAMETER MINIMUM MAXIMUM FACTORY SETTING

Maximum fan speed (HW mode) Fixed Fixed 5.500 RPM
Maximum fan speed (CH mode) See fig. 32 See fig. 32 5.500 RPM
Minimum fan speed Fixed Fixed 1.700 RPM
Soft-light fan speed Fixed Fixed 4.400 RPM
Pre-heat Fixed Fixed 55°C
Pre-heat temperature drop 5°C30°C20°C
Anti-cycle delay 0 seconds 306 seconds 92 seconds
Central heating flow temperature 20°C90°C75°C
Hot water outlet temperature 40°C65°C65°C
Pump over-run 3 m 99 m 10 m

2.12 Emissions MIN. OUTPUT MAX. OUTPUT

NO

x

15 ppm 30 ppm
CO 50 ppm 50 ppm
CO

2

9,8% 9,8%
CO/CO2 ratio 0.0005 to 1 0.0005 to 1

2.13 PUMP DUTY

Fig. 3 shows the flow rate available – after allowing
for pressure loss through the appliance – for
system requirements. When using this graph
apply only the pressure loss of the system. The
graph is based on 20°C temperature differential.

600

500

400

300

200

100

Water pressure (mbar)

0 100 200 300 400 500 600 700 800

Fig. 3

Litres Per Hour (x100)

900 1000

1100 1200 1300 1400

Terminal position for fan assisted boiler

(minimum distance) mm
A - Directly above or below an open window 300

J - From an opening in the car port (e.g. door

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

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, airbric k,

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

NOTE:The flue must be terminated in a place not likely to cause a
nuisance.

Fig. 4

4

window) into dwelling. 1200

openable window, etc. 300

Supplied By www.heating spares.co Tel. [phone]

SECTION 3 GENERAL REQUIREMENTS

This appliance must be installed by a competent
person in accordance with the Gas Safety (Instal­lation & Use) Regulations.

3.1 RELATED DOCUMENTS

The installation of this boiler must be in accord­ance with the relevant requirements of the Gas
Safety (Installation & Use) Regulations, the local
building regulations, the current I.E.E. wiring
regulations, the bylaws of the local water
undertaking, the Building Standards (Scotland)
Regulation and Building Standards (Northern
Ireland) Regulations.

It should be in accordance also with any relevant
requirements of the local authority and the relevant
recommendations of the following British Standard
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.
wiring regulations, and in Scotland, the electrical
provisions of the Building Regulations, with
respect to the installation of the appliance in a
room or internal space containing a bath or shower.

for this purpose. An existing compartment/cup­board may be utilised provided that it is modified
to suit.

Details of essential features of compartment/
cupboard design, including airing cupboard in­stallations, 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
– must be checked to ensure that it is of adequate
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 soundness in
accordance with BS 6891.

If the gas supply serves more than one appliance,
it must be ensured that an adequate supply is
maintained to each appliance when they are in
use at the same time.

BS 5440 PART 1 FLUES
BS 5440 PART 2 FLUES AND VENTILATION
BS 5449 PART 1 FORCED CIRCULATION HOT WATER SYSTEMS
BS 5546 INSTALLATION OF GAS HOT WATER SUPPLIES FOR DOMESTIC PURPOSES

(2ND FAMILY GASES)
BS 6798 BOILERS OF RATED INPUT NOT EXCEEDING 60kW
BS 6891 LOW PRESSURE INSTALLATION PIPES
BS 7074 PART 1 APPLICATION, SELECTION, AND INSTALLATION OF EXPANSION VESSELS AND

ANCILLARY EQUIPMENT FOR SEALED WATER SYSTEMS

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.

The location chosen for the appliance must permit
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

3.4 FLUE SYSTEM

The terminal should be located where the disper­sal of combustion products is not impeded and
with due regard for the damage and discoloration
that may occur to building products located
nearby.
The terminal must not be located in a place where
it is likely to cause a nuisance (see fig. 4).

Water vapour will condense on leaving the flue
terminal, the effect of such pluming must be
considered.

5

Supplied By www.heating spares.co Tel. [phone]

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.
Refer to BS 5440 Part 1, when the terminal is 0,5
metres (or less) below plastic guttering or 1 metre
(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 boiler,
consequently it does not require a permanent air vent
for combustion air supply.

When installed in a cupboard or compartment, venti­lation for cooling purposes is also not required.

3.6 WATER CIRCULATION

Detailed recommendations are given in BS 5449
Part 1 and BS 6798. The following notes are for
general guidance only.

3.6.1 PIPEWORK

It is recommended that copper tubing to BS 2871 Part
1 is used in conjunction with soldered capillary joints.

Where possible pipes should have a gradient to
ensure air is carried naturally to air release points
and that water flows naturally to drain cocks.

Except where providing useful heat, pipes should
be insulated to avoid heat loss and in particular to
avoid the possibility of freezing. Particular atten­tion should be paid to pipes passing through
ventilated areas such as under floors, loft-space,
and void areas.

3.6.2 AUTOMATIC BY-PASS

The appliance has a built-in automatic by-pass,
consequently there is no requirement for an ex­ternal by-pass, however the design of the system
should be such that it prevents boiler ‘cycling’.

3.6.6 FILLING POINT

A method for initial filling of the system and
replacing water lost during servicing etc. must be
provided. This method of filling must comply with
the local water authority regulations.
Fig. 5 shows a widely accepted method.

Fig. 5

3.6.7 LOW PRESSURE SEALED SYSTEM

An alternative method of filling the system would
be from an independent make-up vessel or tank
mounted in a position at least 1 metre above the
highest point in the system and at least 5 metres
above the boiler (see fig. 5 A). The cold feed from
the make-up vessel or tank must be fitted with an
approved non-return valve and stopcock for iso­lation purposes. The feed pipe should be con­nected to the return pipe as close to the boiler as
possible.

Make-up vessel
or tank

Automatic
air-vent

3.6.3 DRAIN COCKS

These must be located in accessible positions 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.

3.6.4 AIR RELEASE POINTS

These must be positioned at the highest points in
the system where air is likely to be trapped. They
should be used to expel trapped air and allow
complete filling of the system.

3.6.5 EXPANSION VESSEL

The appliance has an integral expansion vessel to
accommodate the increased volume of water when

Fig. 5 A

3.6.8 FREQUENT FILLING

the system is heated. It can accept up to 8 litres of
expansion from within the system, generally this is
sufficient, however if the system has an unusually high
water content, it may be necessary to provide additional
expansion capacity (see 6.19).

6

Non-return

valve

Stopcock

5.0 metres minimum

Heating
return

Frequent filling or venting of the system may be
indicative of a leak. Care should be taken during
the installation of the appliance to ensure all
aspects of the system are capable of withstand­ing pressures up to at least 3 bar.

Supplied By www.heating spares.co Tel. [phone]

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
complete isolation from the supply. The preferred
method is by using a double-pole switch with a
contact separation of at least 3mm. The switch
must only supply the appliance and its
corresponding controls, i.e. time clock, room ther­mostat, etc. Alternatively an un-switched shuttered
socket with a fused 3-pin plug both complying
with BS 1363 is acceptable.

3.8 SHOWERS

If the appliance is intended for use with a shower,
the shower must be thermostatically controlled
and be suitable for use with a combination boiler.

3.9 MOUNTING ON A COMBUSTIBLE SURFACE

If the appliance is to be fitted on a wall of combus­tible material, a sheet of fireproof material must
protect the wall.

3.10 TIMBER FRAMED BUILDINGS

If the appliance is to be fitted in a timber framed
building, it should be fitted in accordance with the
Institute of Gas Engineers publication (IGE/UP/

7) “Guide for Gas Installations in Timber Frame
Buildings”.

3.11 CONDENSATE DISPOSAL

When choosing a location for the boiler,
consideration should be given to the disposal of
the condensate discharge into a suitable drain or
soil pipe. The condensate outlet pipe must be
connected to the drain in accordance with building
regulations or other rules in force.

SECTION 4 INSTALLATION

4.1 DELIVERY

The appliance is delivered in a heavy-duty card­board carton. Lay the carton on the floor with the
writing the correct way up.

4.2 CONTENTS

Contained within the carton is:

● the boiler;

● the wall mounting bracket;

● template;

● an accessories pack containing the appliance

service valves and washers;

● the instruction pack containing the installation

& servicing instructions, user instructions,
Benchmark logbook, guarantee registration
card, and a 3amp fuse.

4.3 UNPACKING

At the top of the carton pull both sides open – do
not use a knife – unfold the rest of the carton from

Fig. 6

3.12 INHIBITORS

The system shall be flushed in accordance with
BS 7593. If an inhibitor is to be used, it shall be
from a reputable manufacturer and shall be
administered in strict accordance with the
manufacturers instructions.

around the appliance, carefully remove all pro­tective packaging from the appliance, and lay the
accessories etc. to one side.

4.4 PREPARATION FOR MOUNTING THE
APPLIANCE

The appliance should be mounted on a smooth,
vertical, non-combustible surface, which must be
capable of supporting the full weight of the
appliance. Care should be exercised when
determining the position of the appliance with
respect to hidden obstructions such as pipes,
cables, etc.

When the position of the appliance has been
decided – using the template supplied – carefully
mark the position of the wall-mounting bracket
(see fig. 6) and flue-hole (if applicable).

7

Supplied By www.heating spares.co Tel. [phone]

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
flue may be extended from the outlet elbow in the
horizontal plane (see 2.9). A reduction must also
be made to the maximum length (see table below)
when additional bends are used.

Reduction for additional bends

Bend

Reduction in maximum flue length for each bend

Take the large black gasket - supplied with the
flue terminal kit - and stretch it over the appliance
flue outlet (fig. 7). Using a twisting motion, connect
the boiler top adaptor - supplied with the flue
terminal kit - to the appliance flue outlet ensuring
the male spigot of the adaptor is pushed fully into
the flue outlet spigot of the boiler (fig. 7). Carefully
measure the distance from the centre of the
appliance flue outlet to the edge of the finished
outside wall (dimension X). Add 45mm to
dimension X to give you Dimension Y (see fig
7A). Measure dimension Y from the terminal end
of the concentric flue pipe and cut off the excess.
Pass the concentric flue pipe through the
previously drilled hole. Fit the flue bend to the boiler
top adaptor and insert the concentric flue pipe into
the flue bend ensuring the correct seal is made.

45° bend
90° bend

Part No.
0225720

0225755
0225740
0225745
0225750
0225730
0225735
0225760

0,5 metre
1,0 metre

Horizontal flue terminals and accessories

Description

Horizontal flue kit for use with
add. bends & extensions

350-500 T elescopic extension
0,5m extension
1,0m extension
2,0m extension
45° bend (pair)
90° bend
Wall bracket (5)

Min-Max length
1000mm

350mm-500mm
500mm
1000mm
2000mm
N/A
N/A
N/A

Using the template provided (see fig. 6), mark
and drill a 125mm hole for the passage of the
flue pipe. The hole should ha ve a 1° rise from the
boiler to outside.

Fig. 7A

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.

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 brack et.

FITTING THE HORIZONTAL FLUE KIT

Boiler top

Black

adaptor

gasket

Flue outlet

Boiler

Fig. 7

8

Fig. 7B

Boiler

Push-fit
connection

Boiler top
adaptor

Extension

Supplied By www.heating spares.co Tel. [phone]

4.5.1.1 EXTENDING THE FLUE

Connect the bend – supplied with the terminal kit
– to the top of the boiler using the boiler top
adapter (supplied, see fig. 7). The additional
bends & extensions have push-fit connections,
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 to the maximum equivalent flue
length) to the flue terminal (see fig. 7B & 7C).

NOTE

When cutting an extension to the required length,
you must ensure that the excess is cut from the
plain end of the extension (see fig. 7B & 7C).
Remove any burrs, and check that any seals are
located properly.
You must ensure that the entire flue system is
properly supported and connected.

Push-fit connection

Plain end

Extension pipe

Boiler top adaptor

Vertical flue terminal and accessories

Part No.
0225725

0225770
0225765
0225755
0225740
0225745
0225750
0225730
0225735
0225760

Description
Vertical flue terminal

Pitched roof flashing plate
Flat roof flashing plate
350-500 telescopic extension
0,5m extension
1,0m extension
2,0m extension
45° bend (pair)
90° bend
Wall bracket (4)

Min-Max length
1000 mm

N/A
N/A
350mm-500mm
500mm
1000mm
2000mm
N/A
N/A
N/A

Using the dimensions given in fig. 8 as a reference,
mark and cut a 105mm hole in the ceiling and/or roof.

IMPORTANT

You must ensure that the terminal is at least
300mm from any structure or surface (see fig. 8).
The vertical flue terminal is 1,0 metre in length
and cannot be cut; therefore it may be necessary
to adjust the height of the appliance to suit or use
a suitable extension.
Encure that any horizontal sections of the flue
system have a 1° fall back to the boiler (17mm per
1000mm).

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.

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.

300mm minimum

Boiler

Fig. 7C

4.5.2 CONCENTRIC VERTICAL FLUE

The vertical flue terminal can be connected directly
to the appliance flue outlet. Alternatively, an
extension or bend can be connected to the
appliance flue outlet if desired (see 2.9), however
if additional bends are fitted, a reduction must be
made to the maximum flue length (see table
below).

Reduction for bends

Bend
45° bend

90° bend

Reduction in maximum flue length for each bend
0,5 metre

1,0 metre

Fig. 8

520mm

139mm

9

Supplied By www.heating spares.co Tel. [phone]

NOTE

When cutting an extension to the required length,
you must ensure that the excess is cut from the
plain end of the extension.
Remove any b urrs, and check that an y seals are
located properly .

4.5.3 TWIN FLUE SYSTEM

The Vokera twin flue system enables greater flue
distances to be achieved (see 2.9) than that of the
standard concentric flue system. It can be used f or
horizontal or vertical applications, howev er the twin
flue system must be converted to the dedicated
concentric flue kit for termination. 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 hav e a f all back of 1° back to the

appliance to allow any condensate that forms
in the flue system to drain. Consideration must
also be given to the fact that there is the
possibility of a small amount of condensate
dripping from the terminal.

● Ensure that the entire flue system is adequately

supported, use at least one bracket for each
extension.

● As the exhaust outlet pipe can reach v ery high

temperatures it must be protected to prevent
persons touching the hot surface.

Reduction for bends

Bend
45° bend
90° bend

Reduction in maximum flue length for each bend
1,0 metre

1,0 metre

Twin flue accessories

Part No. Description
0225805

0225810
359
0225770
0225765
0225815
0225820
0225825
0225830
0225835
0225840
0225845
0225850
0225855

Horizontal flue terminal
Vertical flue terminal
Twin adapter kit
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)

MOUNTING THE BOILER

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.

Length
1000 mm

1000 mm
N/A
N/A
N/A
N/A
250mm
500mm
1000mm
2000mm
N/A
N/A
N/A
N/A

4.5.3.1 INSTALLATION OF TWIN ADAPTOR KIT (see fig. 9)

● Discard the restrictor ring (supplied with the twin

adapter kit).

● Insert the exhaust connection manifold onto the

appliance flue outlet.

● Place the silicone seal (supplied with twin

adapter kit) over the rim of the exhaust
connection manifold.

● Remove one of the blanking plate (located to

the left & right of the appliance flue outlet) and
– using the same screws – install the air baffle.

Fig. 9

4.5.3.2 HORIZONTAL TERMINATION (see fig. 10)

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.

Depending on site conditions it may be pref erable
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 boiler (17mm per 1000mm).
Insert the terminal assembly into the flue hole.

Push-fit the twin flue pipes onto the concentric to
twin converter box 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 f or 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.

NOTE

You must ensure that the entire flue system is
properly supported and connected.
When cutting an extension to the required length,
you should ensure that the excess is cut from

10

Supplied By www.heating spares.co Tel. [phone]

the plain end of the extension. Remove an y burrs,
and check that both seals are located properly.

Seal the flue terminal assembly to the wall using
cement or a suitable alternative that will provide
satisfactory weatherproofing. The interior and
exterior trim can now be fitted.

convertor box

Fig. 10

Push-fit the twin flue pipes onto 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 hav e

a 1° fall towards the appliance (17mm per
1000mm).

● The convertor box on the vertical terminal will

have to be temporarily remo ved when inserting
the terminal through the flashing.

4.5.3.3 VERTICAL TERMINATION (see fig. 11)

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.

● A 130mm hole is required for the passage of

the concentric terminal through the ceiling and/
or roof.

Depending on site conditions it may be prefer able
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.

convertor box

4.6 CONNECTING THE GAS AND WATER

The appliance is supplied with an accessories
pack that contains sealing washers and service
valves.
When connecting pipe work to the valves, tighten
the compression end first, then insert the sealing
washers before tightening the valve or connection
to the appliance.

NOTE

It will be necessary to hold the valve with one
spanner whilst tightening with another.

4.6.1 GAS (see fig. 12)

The appliance is supplied with a 1/2 inch BSP
service valve, connect the supply pipe to the inlet
of the valve and tighten the connecting nut.

NOTE

It will be necessary to calculate the diameter of
the gas pipe to ensure the appliance has an
adequate supply of gas.

4.6.2 FLOW & RETURN (see fig. 12)

The appliance is supplied with 22mm service
valves for the flow and return connections, connect
a 22mm pipe to the inlet of each valve and tighten
both nuts.

4.6.3 SAFETY VALVE (see fig. 12)

Fig. 11

Connect a suitable coupling and 15mm pipe to
the safety valve outlet and tighten.The discharge
pipe must have a continuous fall away from the
appliance to outside and allow any water to drain
away thereby eliminating the possibility of freezing.
The discharge pipe must terminate in a position
where any water - possibly boiling - discharges
safely without causing damage or injury, but is
still visible.

11

Supplied By www.heating spares.co Tel. [phone]

4.6.4 COLD WATER INLET (see fig. 12)

The appliance is supplied with a 15mm service
valve, connect a 15mm pipe to the inlet of the
valve and tighten both nuts.

4.6.5 HOT WATER OUTLET (see fig. 12)

The appliance is supplied with a 15mm male
connector. Using a suitable coupling, connect a
15mm pipe to the supplied connector and tighten
the nut.

4.7 CONDENSATE OUTLET (see fig. 12)

During normal operation the boiler produces
condensate which is collected in a trap located in
the lower part of the boiler. A flexible pipe
(condensate outlet pipe) is connected to the
outlet of the trap. The flexible pipe must be
connected to a plastic waste pipe only. The
plastic waste pipe must have a minimum of a 3°
fall towards the drain. Any external run of pipe
should be insulated to prevent the risk of freezing.

CONNECTING THE CONDENSATE OUTLET

Gently pull the condensate outlet pipe down from
its location inside the boiler until approximately
250mm protrudes from the underside of the boiler.
Connect a suitable pipe (no less than 20mm
diameter) to the outlet pipe and ensure it
discharges in accordance with building regulations
or other rules in force.

4.8.1 CASING REMOVAL

To gain access to the appliance electrical con­nections you must first remove the casing, pro­ceed as follows:

● locate and remove the 2 screws that secure the

controls fascia to the appliance casing (see fig. 13).

● locate and remove the 2 screws that secure the

casing to the back frame of the boiler (see fig. 13).

● gently pull one side of the casing then the other

to disengage it from the retaining clips.

● lift the casing upward to disengage it from the

top locating hooks and then remove.

● store the casing and screws safely until required.

Re-fit in the reverse order.

Fig.13

Safety valve

outlet

Condensate

outlet pipe

Fig. 12

Return Gas

Flow

Cold water

inlet

4.8 ELECTRICAL CONNECTIONS

The electrical supply must be as specified in 3.7.
A qualified electrician should connect the electri­cal supply to the appliance. If controls - external
to the appliance - are required, a competent
person must undertake the design of any external
electrical circuits, please refer to section 8 for
detailed instructions.
ANY EXTERNAL CONTROL OR WIRING MUST
BE SERVED FROM THE SAME ISOLATOR AS
THAT OF THE APPLIANCE.
The supply cable from the isolator to the appliance
must be 3-core flexible sized 0,75mm to BS 6500.
Wiring to the appliance must be rated for opera­tion in contact with surfaces up to 90°C.

4.8.2 ELECTRICAL INPUT BOARD

The appliance electrical input board is
located behind the control fascia (see fig.14).
Locate and remove the 4 screws securing
the input board cover.

NOTE

The appliance comes with a factory fitted link to
allow basic operation of the boiler via the keypad.
If it is anticipated that external controls will be
required please refer to the wiring diagrams in
section 8 for more detailed information.

Cable

entries

Hot water

outlet

Fig.14

12