Compact A
High efficiency combi boiler
Users Instructions
Installation &
Servicing
Instructions
Compact A 25 G.C. N° 47-364-17
Compact A 29 G.C. N° 47-364-18
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.
40
Users instructions
Things you should know
1.1
Gas appliances
1.2
Electrical supply
1.3
Guarantee registration card
1.4
Appliance Log Book (UK only)
1.5
How does it work?
1.6
Dimensions
1.7
Clearances required
1.8
Frost protection system
1.9
Appliance status indicators
Page
1
1
1
1
1
1
1
1
1
Getting started
2.1
Before switching ON
2.2
Appliance controls
2.3
Lighting the boiler
2.4
Adjusting the heating temperature
2.5
Adjusting the hot water temperature
2.6
Explanation of features
2.7
Automatic temperature control
Page
3
3
3
3
3
3
3
How to...
3.1
How to top-up the system pressure
3.2
How to reset the appliance
3.3
How to shut down the system for short periods
3.4
How to shut down the system for long periods
3.5
How to care for the appliance
Page
4
4
4
4
4
What if...
4.1
What if I suspect a gas leak
4.2
What if I have frequently top-up the system
4.3
What if the appliance is due its annual service
4.4
What if I need to call an engineer
Page
5
5
5
5
Setting the Vokèra
5.1
Setting the Vokèra mechanical clock
Page
5
Installation and Servicing instructions
Design principles & operating sequence
1.1
Principle components
1.2
Mode of operation (at rest)
1.3
Mode of operation (heating)
1.4
Mode of operation (Hot water)
1.5
Safety devices
Page
7
7
7
7
7
Technical data
2.1
Central heating
2.2
Domestic hot water
2.3
Gas pressures
2.4
Expansion vessel
2.5
Dimensions
2.6
Clearances
2.7
Connections
2.8
Electrical
2.9
Flue details (60/100)
2.9A Flue details (80/125)
2.9B Flue details (twin pipes)
2.10 Efficiency
2.11 Emissions
2.12 Pump duty
Page
8
8
8
8
8
8
8
8
8
8
8
9
9
9
General requirements (UK)
3.1
Related documents
3.2
Location of appliance
3.3
Gas supply
3.4
Flue system
3.5
Air supply
3.6
Water circulation
3.7
Electrical supply
3.8
Mounting on a combustible surface
3.9
Timber framed buildings
3.10 Inhibitors
3.11 Showers
Page
10
10
10
10
10
10
11
11
11
11
11
General requirements (EIRE)
3A.1 Related documents
3A.2 Location of appliance
3A.3 Gas supply
3A.4 Flue system
3A.5 Air supply
3A.6 Water circulation
3A.7 Electrical supply
3A.8 Mounting on a combustible surface
3A.9 Timber framed buildings
3A.10 Inhibitors
3A.11 Showers
3A.12 Declaration of conformity
Page
11
11
11
11
12
12
12
12
12
12
12
12
38
Installation
4.1
Delivery
4.2
Contents
4.3
Unpacking
4.4
Preparation for mounting the appliance
4.5
Fitting the flue
4.6
Connecting the gas & water
4.7
Electrical connections
Page
13
13
13
13
13
17
18
Commissioning
5.1
Gas supply installation
5.2
The heating system
5.3
Initial filling of the system
5.4
Initial flushing of the system
5.5
Pre-operation checks
5.6
Initial lighting
5.7
Checking gas pressure & combustion analysis
5.8
Final flushing of the heating system
5.9
Setting the flow outlet temperature
5.10 Setting the system design pressure
5.11 Regulating the central heating system
5.12 Final checks
5.13 Instructing the user
Page
19
19
19
19
19
19
19
19
19
19
20
20
20
Servicing
6.1
General
6.2
Routine annual servicing
6.3
Replacement of components
6.4
Component removal procedure
6.5
Pump assembly
6.6
Safety valve
6.7
Lower automatic air release valves
6.8
Water pressure switch
6.9
Flow thermistor
6.10 Return thermistor
6.11 Printed circuit board
6.12 Gas valve
6.13 Electrodes
6.14 Flue fan & mixer
6.15 Burner
6.16 Main heat exchanger
6.17 Automatic by-pass & DHW non-return valve
6.18 Expansion vessel removal
6.19 Condense trap removal
6.20 Flue collector removal
Page
20
20
20
21
21
21
21
21
21
21
21
22
22
22
22
23
23
23
23
24
Checks, adjustments and fault finding
7.1
Checking appliance operation
7.2
Appliance modes of operation
7.3
Checking the CO2 & adjusting the valve
7.4
Combustion analysis test
7.5
Checking the expansion vessel
7.6
External faults
7.7
Electrical checks
7.8
Fault finding
7.9
Component values & characteristics
7.10 Adjustments
Page
25
25
25
26
26
26
26
27
27
28
Wiring diagrams
8.1
External wiring
8.2
Typical control applications
8.3
Other devices
8.4
Vokèra lower cover mechanical clock
Page
31
31
31
31
L.P.G. instructions
9.1
Related documents
9.2
Technical data
9.3
Converting the appliance gas type
9.4
Gas supply
9.5
Gas supply installation
9.6
Checking the CO2 and adjusting the gas valve
Page
33
33
33
33
33
33
Benchmark
Commissioning
35-36
37
USERS INSTRUCTIONS
INTRODUCTION
Dear Customer
Your Vokèra Compact A boiler has been designed to meet and exceed the very latest standards in gas central heating technology, and if cared for, will give years of reliable use and efficiency.
Please therefore take some time to read these instructions carefully.
Do’s and Don’t’s
- Do ensure that the system pressure is periodically checked
- Do ensure that the boiler should not be used by children or unassisted disabled people
- Do ensure that you know how to isolate the appliance in an emergency
- Do ensure that you are familiar with the appliance controls
- Do ensure that your installer has completed the appliance log book section
- Do not attempt to remove the appliance casing or gain internal access
- Do not hang clothes etc. over the appliance
- Do not forget to have the appliance serviced annually.
This booklet is an integral part of the appliance. It is therefore necessary to ensure that the booklet is handed to the person responsible for the property in which the appliance is located/installed. A replacement copy can be obtained from Vokèra customer
services.
1. THINGS YOU SHOULD KNOW
1.1 GAS APPLIANCES
Gas Safety (Installations and Use) Regulations (UK).
In the interests of your safety and that of others it is a legal
requirement that all gas appliances are installed and correctly
maintained by a competent person and in accordance with the
latest regulations.
1.2 ELECTRICAL SUPPLY
Please ensure that this appliance has been properly connected
to the electrical supply by means of a double pole isolator or
un-switched socket, and that the correct size of fuse (3 AMP)
has been fitted.
Warning: this appliance must be earthed!
1.3 GUARANTEE REGISTRATION CARD
Please take the time to fill out your guarantee registration card.
The completed warranty card should be posted within 30 days
of installation.
1.6 DIMENSIONS
Compact A 25-29
HEIGHT
715 mm
WIDTH
405 mm
DEPTH
250 mm
1.7 CLEARANCES REQUIRED
ABOVE
BELOW
LEFT SIDE
RIGHT SIDE
FRONT
150 mm
150 mm
12 mm
12 mm
600 mm
1.4 APPLIANCE COMMISSIONING CHECKLIST
(UK only)
1.8 FROST PROTECTION
SYSTEM
A checklist section can be found at the rear of the appliance
installation booklet. This important document must be completed during the installation/commissioning of your boiler. All
GAS SAFE registered installers carry a GAS SAFE ID card,
and have a registration number. These details should be recorded in the Benchmark commissioning checklist section
within the installation booklet. You can check your installers
details by calling GAS SAFE direct on 08004085500. Failure
to install and commission the appliance in accordance with
the manufacturers instructions will invalidate the warranty.
This does not affect your statutory rights.
The Compact A is equipped with
a built-in frost protection system,
this enables the boiler to over-ride
the time controls – even if switched
off – and operate the burner and/or
pump, should the temperature drop
below 50C for the main and for the
DHW line. In particular the burner
will be in ON status until the main
temperature reaches 35°C for CH
appliance and 55°C for DHW appliance. Please note that the frost protection system is designed
to protect the appliance only, should frost protection be required
for the heating system, additional controls may be required.
NOTE
The frost protection system is reliant on the appliance having a
permanent electrical supply, and being in a non-fault condition.
1.5 HOW DOES IT WORK?
Your Compact A boiler supplies heated water to your radiators
and hot water to your hot water taps.
The central heating is controlled via a time clock and any
thermostats that your installer may have fitted. The boiler will
light when it receives a request from the time clock via any
thermostat that may be installed, or whenever a hot water
outlet (tap) is opened.
Your Compact A boiler lights electronically and does not have
a pilot light.
In the unlikely event of a fault developing with your boiler, the
supply of gas to the burner will be terminated automatically.
1.9 APPLIANCE STATUS INDICATORS
Your boiler is equipped with a large LCD display that indicates
the appliance operating status.
1
Fig. 1
MODE
SELECTOR SWITCH
DISPLAY
PRESSURE GAUGE
HEATING
TEMPERATURE
SELECTOR
HOT WATER
TEMPERATURE
SELECTOR
HOT WATER TEMPERATURE SELECTOR
Move the selector clockwise to increase the hot water outlet temperature, or counter-clockwise to reduce the temperature
PRESSURE GAUGE
Ensure the system pressure is set correctly (minimum 0.5-bar)
MODE SELECTOR SWITCH/HEATING TEMPERATURE SELECTOR
Mode selector switch:
Hot water only - Select this position if you want the boiler to supply hot
water only (no heating)
Hot water temperature selector: move the selector clockwise to increase
the DHW outlet temperature, or counter-clockwise to reduce the temperature
(range: 37°C-60°C). The display shows the temperature values.
DHW pre-heat function - Turning the domestic hot water temperature
adjustment knob to the symbol activates the pre-heating function. Bring the
domestic hot water temperature adjustment knob back to the required position. The activation of this function is indicated on display with the P icon
ON. This function keeps the water in the domestic hot water exchanger
hot, to reduce standby times when a request is made. The display shows
the delivery temperature of the heating water or the domestic hot water,
according to the current request. To deactivate the pre-heat function, rotate
the domestic hot water temperature adjustment knob back to the symbol.
Bring the domestic hot water temperature adjustment knob back to the
required position. This function cannot be activated when the boiler is OFF:
function selector to OFF position.
Heating & hot water - Select this position when you want the boiler to respond to a heating and hot water request from the time-clock programmer
Heating temperature selector: move the selector clockwise to increase the
heating outlet temperature, or counter-clockwise to reduce the temperature
(range: 40°C-80°C for standard central heating).
The automatic temperature control function (SARA) is set within the blank
bullet points.
The display shows the temperature values.
SARA function
Boiler at OFF/standby - Select this position when you want the boiler to
be switched off for short periods (days) or if the boiler requires to be reset
The display shows “- -”.
Pressure gauge shows the current pressure of your heating system, the
gauge should be set between 1 and 1.5 BAR. When the appliance is operating the gauge may rise or fall slightly, this is quite normal. The minimum
permissible level for the safe and efficient operation of the appliance is 0.5
BAR. Should the pressure fall below 0.5 BAR, the boiler may lockout.
2
correct pressure
value
DIGITAL DISPLAY
Fig. 2
Symbol/Icon
Description
Displayed when heating mode is active
Displayed when hot water mode is active
Displayed when frost protection function is active
65
Displayed when hot-water pre-heat function is
enabled. Flashes when functioning
Displayed if an alarm or fault has been detected
Displayed when low system pressure has been
detected
Displayed when an external sensor is connected
to the boiler
Displayed if an ignition fault has been detected
2. GETTING STARTED
2.1 BEFORE SWITCHING ON
2.4 ADJUSTING THE HEATING TEMPERATURE
Before switching the appliance on, please familiarise yourself
with:
- how to isolate the appliance from the gas, water, and electricity
supplies;
- how to check and top-up – if necessary – the system water
pressure;
- the time clock or programmer (if fitted);
- any external thermostats and their functions;
- the appliance controls.
Rotate the temperature selector – clockwise to increase, counterclockwise to decrease – to the desired temperature setting. The
temperature can be set from a minimum of 40°C to a maximum
of 80°C (if standard CH mode is selected).
2.2 APPLIANCE CONTROLS (see fig. 1)
The appliance controls are situated on the lower front of the
appliance. The appliance controls include:
- pressure gauge;
- appliance mode selector;
- temperature selector;
- optional integral time clock/programmer (if fitted).
NOTE
The appliance frost protection is active in all the boiler modes.
The temperature selectors can be used to vary the temperature
of the water that circulates around your radiators and the water
that flows from your hot water taps. The temperature range is
adjustable between 40oC and 80oC for the central heating, and
between 37oC and 60oC for the hot water.
Refer to the main appliance status table for fault indicator and
boiler status.
The integral digital time clock is used to switch the heating on
and off at pre-determined intervals
2.3 LIGHTING THE BOILER
2.5 ADJUSTING THE HOT WATER TEMPERATURE
Rotate the temperature selector – clockwise to increase,
counter-clockwise to decrease – to the desired temperature
setting. The temperature can be set from a minimum of 37°C
to a maximum of 60°C. If the temperature at the outlet is still
not sufficiently hot enough, it may be necessary to reduce the
flow of water at the hot water outlet (tap).
NOTE
If the appliance fails to ignite during the ignition sequence, it
will enter a lockout condition. Should this occur, please allow
a period of at least two minutes before re-setting the appliance.
2.6 EXPLANATION OF FEATURES
Although the Vokèra Compact A has been designed for simplicity
of use, it utilises the latest in boiler technology, enabling a host
of functions to be carried out simultaneously.
2.7 AUTOMATIC TEMPERATURE CONTROL
The automatic temperature control function (SARA), permits the
boiler (when the heating temperature selector is set within the
blank bullet points) to automatically adjust (raise) the heating.
The activation and the disable of the function is visualized on
the display if the heating temperature is selected between
55° - 65°C.
Ensure the gas and electrical supply to the boiler are
turned on.
Turn the mode selector switch to the ON position. When there
is a request for heating or hot water via the time clock or programmer, the boiler will begin an ignition sequence. When the
appliance reaches the CH set temperature, the burner will go
off for a minimum period of approximately 3 minutes.
When the programmer/time clock or external thermostats
heating request has been satisfied, the appliance will switch
off automatically.
3
3. HOW TO...
3.1 HOW TO TOP-UP THE SYSTEM PRESSURE
(fig. 1-2)
3.3 HOW TO SHUT DOWN THE SYSTEM FOR
SHORT PERIODS
The system pressure must be checked periodically to ensure the
correct operation of the boiler. The needle on the gauge should
be reading between 1 and 1.5 BAR when the boiler is in an off
position and has cooled to room temperature. If the pressure
requires ‘topping-up’ use the following instructions as a guide.
- Locate the filling valve connections (usually beneath the
boiler, see fig. 3).
- Attach the filling loop to both connections.
- Open the filling valve slowly until you hear water entering the
system.
- Close the filling valve when the pressure gauge (on the boiler)
reads between 1 and 1.5 BAR (see fig. 1).
- Remove the filling loop from the connections.
The system and boiler can be shut down for short periods by
simply turning the time clock to the off position. It is also advisable to turn off the main water supply to the house.
3.2 HOW TO RESET THE APPLIANCE
When the fault code is displayed, the appliance will require to
be reset manually. Before resetting the boiler, check what action
is required to be taken, using the information on the fault code
table below. Allow a period of two minutes to elapse before rotate
the mode selector knob across the
position (see fig. 1).
IMPORTANT
If the appliance requires to be reset frequently, it may be indicative of a fault, please contact your installer or Vokèra Customer
Services for further advice.
3.4 HOW TO SHUT DOWN THE SYSTEM FOR
LONG PERIODS
If the house is to be left unoccupied for any length of time –
especially during the winter – the system should be thoroughly
drained of all water. The gas, water, and electricity supply to
the house should also be turned off. For more detailed advice
contact your installer.
3.5 HOW TO CARE FOR THE APPLIANCE
To clean the
outer casing use only
a clean damp
cloth. Do not
use any scourers or abrasive
cleaners.
_St
_CL
A01
A02
A03
A04
A06
A07
A08
A09
A11
A77
Adj
ACO
P
P blinking
Hours
-4
control
valve
temporary
connection
flow/return
pipe
double
check valve
supply pipe
Fig. 3
FAULT CODES
ALARM CODE CAUSE
control
valve
ALARM TYPE
ACTION
AUTOSTOP
Final
Call engineer
CALL FOR SERVICE
Temporary then final
Call engineer
Ignition failure, flame not sensed,
internal fault
Final
Reset, check appliance operation
Limit thermostat fault
Final
Reset, check appliance operation
Fan tacho signal fault
Final
Reset check appliance operation, check fan
Insufficient system water pressure
Final
Check/refill system pressure, reset, check
appliance operation
DHW thermistor fault
Temporary
Check DHW thermistor
Primary (flow) thermistor fault
Temporary
Check primary thermistor, check wiring
Primary (flow) thermistor over temperature Temporary then final
Reset, check appliance operation
Temperature differential
Final
Reset, check appliance operation, check
thermistors
Return thermistor fault
Temporary
Check return thermistor, check wiring
Return thermistor over temperature
Temporary then final
Reset, check appliance operation
Temperature differential inverted
Final
Reset, check pump, ensure there is sufficient circulation around heating circuit/s
Flue thermistor or flue thermistor
Temporary
counter fault
Check flue thermistor counter at power
on, check flue thermistor, check wiring
Flue thermistor over temperature
Final
Reset, check appliance operation
False flame
Temporary
None
Low temperature thermostat fault
Temporary
Check low temperature thermostat
Calibration
Na
None
Service operation
Na
None
Purge cycle mode active
Na
None
Preheating function active
Na
None
Preheating function running
Na
None
Flame ON
Na
None
Stand-by
Na
None
OFF
Na
None
4. WHAT IF...
4.1 WHAT IF I SUSPECT A GAS LEAK
If you suspect a gas leak, turn off the gas supply at the gas
meter and contact your installer or local gas supplier. If you
require further advice please contact your nearest Vokèra office.
4.2 WHAT IF I HAVE FREQUENTLY TO TOP-UP
THE SYSTEM
If the system regularly requires topping-up, it may be indicative
of a leak. Please contact your installer and ask him to inspect
the system.
4.3 WHAT IF THE APPLIANCE IS DUE ITS ANNUAL SERVICE
Advice for homeowners
Please contact Vokèra Customer Service (0844 3910999 (UK)
or 056 7755057 (ROI) if you would prefer a Vokèra service
engineer or agent to service your appliance. Alternatively your
local GAS SAFE registered engineer may be able to service
the appliance for you.
4.4 - WHAT IF I NEED TO CALL AN ENGINEER
If you think your boiler may have developed a fault, please contact
your installer or Vokèra Customer Services (0844 3910999 (UK)
or 056 7755057 (ROI) have all your details to hand including
full address and postcode, relevant contact numbers, and your
completed appliance log book.
Advice for tenants only
Your landlord should arrange for servicing.
5. SETTING THE VOKÈRA...
5.1 - SETTING THE VOKÈRA MECHANICAL
CLOCK
If your boiler has been installed with the Vokèra mechanical
clock, it can be used and adjusted as follows:
Setting the time
The time of day can be set by grasping the outer edge of the
black dial and turning it in a clockwise direction until the correct
time is in line with the white pointer.
Setting the “switching times”
The “ON” periods are set by sliding the black tappets, adjacent to the time periods required, to the outer edge of the dial.
The tappets that remain at the centre of the dial will be the
“OFF” periods.
The smallest switching time (ON or OFF) is 15 minutes.
To select “AUTO” mode move the selector switch in central
position.
To select “ON” mode move the selector switch in the bottom
position.
To select “OFF” mode move the selector switch in the upper
position.
OFF
AUTO
ON
Fig. 4
5
INSTALLATION AND SERVICING INSTRUCTIONS
INTRODUCTION
All installers are asked to follow the Benchmark Scheme by
adhering to the Code of Practise, which can be obtained from
www.centralheating.co.uk.
The Compact A comprises a range of high-efficiency combination boilers with outputs to DHW of 25kW and 30kW respectively. These appliances – by design – incorporate electronic
ignition, circulating pump, expansion vessel, safety valve, pressure gauge and automatic by-pass.
The Compact A range is produced as room sealed, category
II2H3P appliances, suitable for internal wall mounting applications only. Each appliance 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 Compact A can also be
used with the Vokèra twin flue system.
The Compact A is approved for use with C13 & C33 type flue
applications.
These appliances are designed for use with a sealed system
only; consequently they are not intended for use on open
vented systems.
This booklet is an integral part of the appliance. It is therefore
necessary to ensure that the booklet is handed to the person
responsible for the property in which the appliance is located/
installed. A replacement copy can be obtained from Vokèra
customer services.
General layout
1
Domestic hot water heat exchanger
2
Drain valve
3
Three porte valve actuator
4
Safety valve
5
Pump
6
Bottom auto air vent (AAV)
7
Main heat exchanger
8
Flues thermistor (NTC)
9
Fan assembly with mixer
10 Silencer
11 Flue gas analysis test point
12 Flue outlet & air intake
13 Ignition transformer
14 Top AAV+De-aerator
15 Spark Electrode
16 Sensing Electrode
17 Flow thermistor (NTC) - High limit thermostat
18 Expansion vessel
19 Pressure switch
20 Return thermistor (NTC)
21 Gas valve
22 Domestic hot water sensor
23 Condense trap
24 DHW flow switch
R
F
G
O
I
Fig. 5
6
R
F
G
O
I
Heating return connection
Heating flow connection
Gas connection
Hot water outlet
Cold water inlet
SECTION 1 - DESIGN PRINCIPLES AND OPERATING SEQUENCE
1.1 PRINCIPLE COMPONENTS
1.5 SAFETY DEVICES
• A fully integrated electronic control board featuring electronic
temperature control, anti-cycle control, pump over-run, selfdiagnostic fault indicator, full air/gas modulation
• Aluminium heat exchanger
• Electronic ignition with flame supervision
• Integral high-head pump
• Fan
• Expansion vessel
• Water pressure switch
• Flue sensor
• Pressure gauge
• Safety valve
When the appliance is in use, safe operation is ensured by:
• a water pressure switch that monitors system water pressure
and will de-activate the pump, fan, and burner should the
system water pressure drop below the rated tolerance;
• fan speed sensor to ensure safe operation of the burner;
• a high limit thermostat that over-rides the temperature control
circuit to prevent or interrupt the operation of the burner;
• flame sensor that will shut down the burner when no flame
signal is detected;
• flue sensor;
• a safety valve which releases excess pressure from the
primary circuit.
1.2 MODE OF OPERATION (at rest)
When the appliance is at rest and there are no requests for
heating or hot water, the following functions are active:
• frost-protection system – the frost-protection system protects
the appliance against the risk of frost damage both for CH
and DHW. For CH line, if the main temperature falls to 5°C,
the appliance will function on minimum power until the temperature on main reaches 35°C.
Moreover if the DHW temperature falls to 5°C, the appliance
will function on minimum power until the temperature on main
reaches 55°C.
• anti-block function – the anti-block function enables the pump
and divertor valve actuator to be energised for short periods,
when the appliance has been inactive for more than 24-hours.
1.3 MODE OF OPERATION (Heating)
When there is a request for heat via the time clock and/or any
external control, the pump and fan are started, the fan speed
will modulate until the correct signal voltage is received at the
control PCB. At this point an ignition sequence is enabled.
Ignition is sensed by the electronic circuit to ensure flame stability
at the burner. Once successful ignition has been achieved, the
electronic circuitry increases the gas rate to 75% for a period of
15 minutes. Thereafter, the boiler’s output will either be increase
to maximum or modulate to suit the set requirement. When
the appliance reaches the desired temperature the burner will
shut down and the boiler will perform a three-minute anti-cycle
(timer delay).
When the request for heat has been satisfied the appliance
pump and fan may continue to operate to dissipate any residual
heat within the appliance.
1.4 MODE OF OPERATION (Hot water)
When there is a request for DHW via a hot water outlet or tap,
the pump and fan are started, the fan speed will modulate until
the correct signal voltage is received at the control PCB. At this
point an ignition sequence is enabled.
Ignition is sensed by the electronic circuit to ensure flame stability at the burner. Once successful ignition has been achieved,
the electronic circuitry increases the gas rate to maximum or
will modulate output to stabilise the temperature.
In the event of the appliance exceeding the desired temperature
(set point) the burner will shut down until the temperature drops.
When the request for DHW has been satisfied the appliance
pump and fan may continue to operate to dissipate any residual
heat within the appliance.
Top AAV
Main heat
exchanger
Flow temperature
sensor
Return
temperature
sensor
Expansion
vessel
Pressure
switch
Bottom
AAV
DHW heat
exchanger
DHW temperature
sensor
DHW
non return
valve
Pump
Safety
valve
Diverter
valve
Automatic
by-pass
Drain
valve
Fig. 6
CH
return
Flow regulator
CH
flow
DHW
outlet
DHW flow
switch
DHW
inlet
7
SECTION 2 - TECHNICAL DATA
2.1 Central Heating
Compact A 25
Compact A 29
Heat input (kW)
20.00
25.00
Maximum heat output (kW) 60/80°C
19.50
24.45
Minimum heat output (kW) 60/80°C
4.91
5.90
Maximum heat output (kW) 30/50°C
20.84
26.23
Minimum heat output (kW) 30/50°C
5.36
6.40
Minimum working pressure
0.25-0.45 bar
Maximum working pressure
2.5 bar
Minimum flow rate
2.2 Domestic Hot Water
350 l/h
Compact A 25
Compact A 29
Heat input (kW)
25.00
29.00
Flow Rate: ΔT35°C
10.20
11.9
Maximum inlet pressure
6 bar
Minimum inlet pressure
0.15 bar
Minimum flow rate
2 l/min
2.3 Gas Pressures
Compact A 25
Compact A 29
Inlet pressure (G20)
20.0 mbar
20.0 mbar
Heating maximum gas rate (m3/hr)
2.12
2.64
DHW maximum gas rate (m3/hr)
2.64
3.07
Minimum gas rate (m3/hr)
0.53
0.63
Injector size (mm)
5.1
5.6
Silencer flange (ø mm) (fitted)
31
-
2.4 Expansion Vessel
Compact A 25
Compact A 29
Capacity
8 litres
Maximum system volume
74 litres
Pre-charge pressure
2.5 Dimensions
1 bar
Compact A 25
Compact A 29
Height (mm)
715
Width (mm)
405
Depth (mm)
250
Dry weight (kg)
26
2.6 Clearances
Compact A 25
Sides
Top
Compact A 29
12mm
150mm from casing or 25mm above flue elbow (whichever is applicable)
Bottom
150mm
Front
2.7 Connections
27
600mm
Compact A 25
Compact A 29
Flow & return
22mm
Gas
15mm
DHW hot & cold
15mm
Safety valve
15mm
Condense
2.8 Electrical
Power consumption (Watts)
21mm
Compact A 25
Compact A 29
110
119
Voltage (V/Hz)
230/50
Internal fuse
3.15A T (for PCB) - 3.15A F (for connections block)
External fuse
3A
2.9 Flue Details (concentric 60-100)
Compact A 25
Compact A 29
Maximum horizontal flue length (60/100mm)
5.85m
4.85m
Maximum vertical flue length (60/100mm)
6.85m
5.85m
2.9A Flue Details (concentric 80-125)
Compact A 25
Compact A 29
Maximum horizontal flue length (80/125mm)
15.3m
12.8m
Maximum vertical flue length (80/125mm)
20.3m
17.8m
2.9B Flue Details (twin pipes)
Compact A 25
Compact A 29
Maximum horizontal flue length (80mm/80mm)
45m/45m
40m/40m
Maximum vertical flue length (80mm/80mm)
45m/45m
40m/40m
8
2.10 Efficiency
Compact A 25
Compact A 29
90.0
90.2
Compact A 25
Compact A 29
SEDBUK (%)
2.11 Emissions
CO2 @ maximum output (%)
9.0
9.0
CO2 @ minimum output (%)
9.5
9.5
CO @ maximum output (ppm)
180
160
CO @ minimum output (ppm)
20
20
class 5
class 5
NOx rating
2.12 PUMP DUTY
4,5
4,0
Residual head (x 100 mbar)
Fig. 6 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
a 20oC temperature differential.
5,0
3,5
3,0
3rd
2,5
sp
ee
2,0
2n
d
sp
ee
1s
d
ts
1,5
d
pe
ed
1,0
0,5
0,0
0
100
200
300
Fig. 7
400
500
600
700
800
900
1000
Flow rate (l/h)
Fig. 8
Key
Location
A
B
C
D
E
F
G
H
I
J
K
L
M
N
P
Q
Below an opening (window, air-brick, etc.)
Above an opening (window, air-brick, etc.)
To the side of an opening (window, air-brick, etc.)
Below gutter, drain-pipe, etc.
Below eaves
Below balcony, car-port roof, etc.
To the side of a soil/drain-pipe, etc.
From internal/external corner
Above ground, roof, or balcony level
From a surface or boundary facing the terminal
From a terminal facing a terminal
From an opening in the car-port into the building
Vertically from a terminal on the same wall
Horizontally from a terminal on the same wall
From a structure to the side of the vertical terminal
From the top of the vertical terminal to the roof flashing
R
S
T
V
W
To the side of a boundary
To the side of an opening or window on a pitched roof
Below an opening or window on a pitched roof
From a vertical terminal to an adjacent opening (window, air-brick, etc.)
From a vertical terminal to an adjacent vertical terminal
Minimum distance
300 mm
300 mm
300 mm
25 mm
25 mm
25 mm
25 mm (60mm for 80/125 - 5” flue)
25 mm (60mm for 80/125 - 5” flue)
300 mm
600 mm
1200 mm
1200 mm
1500 mm
300 mm
300 mm
As determined by the fixed collar
of the vertical terminal
300 mm
600 mm
2000 mm
(call Vokera technical for advice)
300 mm (only if both terminals are the same hight)
9
SECTION 3 - GENERAL REQUIREMENTS (UK)
This appliance must be installed by a competent person in accordance with the Gas Safety (Installation & Use) Regulations.
BS 5440 Part 1, when the terminal is 0.5 metres (or less) below
plastic guttering or 1 metre (or less) below painted eaves.
3.1 RELATED DOCUMENTS
3.5 AIR SUPPLY
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.
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.
3.2 LOCATION OF APPLIANCE
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.
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
BS 5440
BS 5440
BS 5449
BS 5546
BS 6798
BS 6891
BS 7074
PART 1
PART 2
PART 1
PART 1
Detailed recommendations are given in BS 5449 Part 1 and
BS 6798. The following notes are for general guidance only.
FLUES
FLUES & VENTILATION
FORCED CIRCULATION HOT WATER SYSTEMS
INSTALLATION OF GAS HOT WATER SUPPLIES FOR DOMESTIC PURPOSES
INSTALLATION OF BOILERS OF RATED INPUT NOT EXCEEDING 60kW
LOW PRESSURE INSTALLATION PIPES
APPLICATION, SELECTION, AND INSTALLTION OF EXPANSION VESSELS
AND ANCILLARY EQUIPMENT FOR SEALED WATER SYSTEMS
containing a bath or shower.
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 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
tightness in accordance with BS6891.
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.
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. 8). In cold and/or humid
weather, water vapour will 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. Refer to
10
3.6 WATER CIRCULATION
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’.
3.6.3 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 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 6.18).
3.6.6 FILLING POINT
A method for initial filling of the system and replacing water lost
during servicing etc. directly from the mains supply, is provided
(see fig. 9). This method of filling complies with the current Water
Supply (Water Fittings) Regulations 1999 and Water Bylaws
2000 (Scotland). If an alternative location is preferred, it should
be connected as detailed in fig. 9.
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. 10).
The cold feed from the make-up vessel or tank must be fitted
with an approved non-return valve and stopcock for isolation
3.6.8 FREQUENT FILLING
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.
3.11 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.
control
valve
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 3,5mm (3° high-voltage category). 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.
temporary
connection
flow/return
pipe
Fig. 9
supply
pipe
Make-up vessel
or tank
3.8 MOUNTING ON A COMBUSTIBLE SURFACE
If the appliance is to be fitted on a wall of combustible material,
there is no requirement to protect the wall.
double
check valve
control
valve
Automatic
air-vent
3.9 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’.
Non-return
valve
Stopcock
5.0 metres minimum
purposes. The feed pipe should be connected to the return pipe
as close to the boiler as possible.
3.10 INHIBITORS
Vokèra recommend that an inhibitor - suitable for use with
aluminium heat exchangers - is used to protect the boiler and
system from the effects of corrosion and/or electrolytic action.
The inhibitor must be administered in strict accordance with
the manufacturers instructions*.
*Water treatment of the complete heating system - including
the boiler - should be carried out in accordance with BS 7593
and the Domestic Water Treatment Association’s (DWTA) code
of practice.
Fig. 10
Heating
return
SECTION 3A - GENERAL REQUIREMENTS (EIRE)
This appliance must be installed by a competent person in
accordance with and defined by, the Standard Specification
(Domestic Gas Installations) Declaration (I.S. 813).
3A.1 RELATED DOCUMENTS
The installation of this boiler must be in accordance with the
relevant requirements of the local building regulations, the
current ETCI National Rules for Electrical Installations and the
bylaws of the local water undertaking.
It should be in accordance also with any relevant requirements
of the local and/or district authority.
3A.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 ETCI National Rules for Electrical Installations, and
I.S. 813, Annex K.
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,
refer to I.S. 813 for detailed guidance on this aspect.
A compartment used to enclose the appliance must be de-
signed and constructed specifically for this purpose. An existing compartment/cupboard may be utilised provided that it is
modified to suit.
This appliance is not suitable for external installation.
3A.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 I.S. 813.
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
tightness in accordance with I.S. 813.
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.
3A.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 I.S. 813).
In cold and/or humid weather, water vapour will 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)
11
the terminal must be protected by a guard of durable material.
The guard must be fitted centrally over the terminal. Refer to
I.S. 813, when the terminal is 0.5 metres (or less) below plastic
guttering or 1 metre (or less) below painted eaves.
3A.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.
3A.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 3,5 mm (3° high-voltage category). The switch must only
supply the appliance and its corresponding controls, i.e. time
clock, room thermostat, etc.
3A.8 MOUNTING ON A COMBUSTIBLE SURFACE
3A.6 WATER CIRCULATION
If the appliance is to be fitted on a wall of combustible material,
there is no requirement to protect the wall.
Specific recommendations are given in I.S. 813. The following
notes are for general guidance only.
3A.9 TIMBER FRAMED BUILDINGS
3A.6.1 PIPEWORK
It is recommended that copper tubing be 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.
3A.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’.
3A.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.
3A.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.
3A.6.5 EXPANSION VESSEL
The appliance has an integral expansion vessel to accommodate the increased volume of water when 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 6.18).
3A.6.6 FILLING POINT
A method for initial filling of the system and replacing water lost
during servicing etc. is provided (see fig. 9). You should ensure
this method of filling complies with the local water authority
regulations.
3A.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. 10). The cold feed from the
make-up vessel or tank must be fitted with an approved nonreturn valve and stopcock for isolation purposes. The feed pipe
should be connected to the return pipe as close to the boiler
as possible.
3A.6.8 FREQUENT FILLING
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.
12
If the appliance is to be fitted in a timber framed building, it
should be fitted in accordance with I.S. 813 and local Building
Regulations.
The Institute of Gas Engineers publication (IGE/UP/7) ‘Guide
for Gas Installations in Timber Frame Buildings’ gives specific
advice on this type of installation.
3A.10 INHIBITORS
Vokèra recommend that an inhibitor - suitable for use with
aluminium heat exchangers - is used to protect the boiler and
system from the effects of corrosion and/or electrolytic action.
The inhibitor must be administered in strict accordance with
the manufacturers instructions*.
*Water treatment of the complete heating system - including
the boiler - should be carried out in accordance with I.S. 813
and the Domestic Water Treatment Association’s (DWTA) code
of practice.
3A.11 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.
3A.12 DECLARATION OF CONFORMITY
A Declaration of Conformity (as defined in I.S. 813) must be
provided on completion of the installation.
A copy of the declaration must be given to the responsible
person and also to the gas supplier if required.
SECTION 4 - INSTALLATION
4.1 DELIVERY
Due to the weight of the appliance it may be necessary for
two people to lift and attach the appliance to its mounting. The
appliance is contained within 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 bracket
• carton template
• an accessories pack containing appliance service connections
and washers
• the instruction pack containing the installation, servicing &
user instructions, guarantee registration card and a 3-amp
fuse.
29450126
29450127
29450128
529
1000mm extension
2000m extension
Telescopic extension
Wall bracket pack (5)
1000mm
2000mm
372/519mm
208mm
Using the template provided (A), mark and drill a 125mm hole
for the passage of the flue pipe. The hole should be drilled to
ensure any condense fluid that forms, is allowed to drain back to
the appliance (see fig. 13). 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.
4.3 UNPACKING
At the top of the carton pull both sides open – do not use a
knife – unfold the rest of the carton from around the appliance,
carefully remove all protective packaging from the appliance and
lay the accessories etc. to one side. Protective gloves should
be used to lift the appliance, the appliance back-frame should
be used for lifting points.
A
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 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. 11) and flue-hole (if applicable).
4.5 FITTING THE FLUE
The top flue outlet permits both horizontal and vertical flue applications to be considered, alternatively, the Vokèra 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 can be used with either the Vokèra condensing
60/100mm concentric flue system or the optional 80/125mm
concentric flue system.
NOTE
These instructions relate only to the Vokèra condensing
60/100mm concentric flue system. For specific details on the
installation of the 80/125mm concentric flue system please refer
to the instructions supplied. The appliance flue outlet elbow can
be rotated through 360º 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
45º bend 1.3 metre (60/100) - 1.0 metre (80/125)
90º bend 1.6 metre (60/100) - 1.5 metre (80/125)
Horizontal flue terminals and accessories
Part No.
Description
29450120
Horizontal flue kit
29450121
Telescopic flue kit
522
Plume management kit
29450123
90-degree bend
29450124
45-degree bends (pair)
29450125
500mm extension
Length
900mm
455/630mm
1370mm
N/A
N/A
500mm
Fig. 11
Outer clamps
Terminal or
extension
Fig. 12
FITTING THE TELESCOPIC HORIZONTAL FLUE KIT
In some instances It may necessary to cut the inner 60mm pipe
of the flue bend at the point indicated (fig.13a pos. A) to allow
for easier insertion to the boiler flue spigot.
FITTING THE HORIZONTAL FLUE KIT
Carefully measure the distance from the centre of the appliance
flue outlet to the edge of the finished outside wall (dimension
X). Add 65mm to dimension X to give you Dimension Y (see
fig 13). Measure dimension Y from the terminal end of the concentric flue pipe and cut off the excess ensuring any burrs are
removed. Pass the concentric flue pipe through the previously
drilled hole. Fit the flue bend to the boiler flue outlet and insert
the concentric flue pipe into the flue bend ensuring the correct
seal is made. Using the clamp, gasket, and screws supplied,
secure the flue bend to the appliance flue spigot.
NOTE
Fit the internal (white) trim to the flue assembly prior to connecting the flue pipe to the bend.
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 exterior trim can now be fitted.
13
4.5.1.2 FITTING THE REAR FLUE (fig. 15) (rear flue outlet
only)
Using the template provided, mark and drill a 125mm hole
for the passage of the flue pipe. The hole should be drilled
LEVEL to ensure any condense fluid that forms, is allowed
to drain back to the appliance. The fixing holes for the wallmounting 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, attach the rear flue terminal to the
appliance (using the previously retained screws) and fix the
telescopic terminal to the correct length (wall thickness) ensuring that the terminal will protrude through the wall by the
correct distance. At this point, lift the appliance and carefully
insert the terminal into and through the wall, ensuring that the
holes in the appliance back frame are aligned with the studs
on the wall bracket.
Fig. 13
A
Fig.13a
EXTENDING THE FLUE
Connect the bend – supplied with the terminal kit – to the top
of the boiler using clamp (supplied) see fig. 12. 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. 12-22). The flue system should have
a minimum of 1º; maximum of 3º rise from the boiler to outside,
to ensure any condense fluid that forms, is allowed to drain
back to the appliance.
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. 12-22). Remove any burrs, and check that all 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.
Fig.15
Fig.16
Fig.17
Using the screws and washers provided, secure the appliance onto the wall bracket and tighten with a suitable spanner.
Seal the flue assembly to the wall using cement or a suitable
alternative that will provide satisfactory weatherproofing. The
exterior wall trim can now be fitted.
Part No.
Fig. 14
14
29450133
Description
Length
Rear flue terminal
825mm
4.5.2 CONCENTRIC VERTICAL FLUE
The appliance can be used with either the Vokèra condensing
60/100mm concentric flue system or the optional 80/125mm
concentric flue system.
NOTE
These instructions relate only to the Vokèra condensing
60/100mm concentric flue system. For specific details on the
installation of the 80/125mm concentric flue system please refer
to the instructions supplied.
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, however if
additional bends are fitted, a reduction must be made to the
maximum flue length (see table below).
Reduction for bends
Bend
Reduction in maximum flue length for each bend
45º bend 1.3 metre (60/100) - 1.0 metre (80/125)
90º bend 1.6 metre (60/100) - 1.5 metre (80/125)
Vertical flue terminal and accessories
Part No.
29450122
531
532
29450123
29450124
29450125
29450126
29450127
29450128
529
Description
Vertical flue terminal
Pitched roof flashing plate
Flat roof flashing plate
90-degree bend
45-degree bends (pair)
500mm extension
1000mm extension
2000mm extension
Telescopic extension
Wall bracket pack (5)
Length
1000mm
N/A
N/A
N/A
N/A
500mm
1000mm
2000mm
372/519mm
208mm
Using the dimensions given in fig. 13 as a reference, mark and
cut a 125mm hole in the ceiling and/or roof.
IMPORTANT
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.
Connect the vertical flue assembly to the boiler flue spigot using the 100mm clip, gasket & screws (supplied), ensuring the
correct seal is made. The flue support bracket (supplied with
the vertical flue kit) can now be fitted.
If the vertical flue requires extension/s or additional bend/s,
connect the required number of flue extensions or bends (up
to the maximum equivalent flue length) between the boiler and
vertical flue assembly (see fig. 22).
Ensure that any horizontal sections of the flue system have a
minimum 1º; maximum 3º fall back to the boiler (1º = 17mm
per 1000mm).
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 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
The Vokèra twin flue system enables greater flue distances
to be achieved than that of a 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 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 have a have a minimum 1º; maximum 3º (1º =
17mm per 1000mm) fall back to the appliance to allow any
condensate that may form in the flue system to drain via the
condensate 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 very high temperatures
it must be protected to prevent persons touching the hot
surface.
• The condensate drain pipe must be connected in accordance
with building regulations.
Reduction for bends
Bend Reduction in maximum flue length for each bend
45º bend
1.0 metre
90º bend
1.5 metre
Twin flue accessories
RTN FLOW
GAS HOT COLD
Fig. 18
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.
Part No.
0225805
0225810
359
531
532
0225815
0225820
0225825
0225830
0225835
0225840
0225845
0225850
0225855
Description
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)
45º bend (pair)
90º bend (pair)
Twin bracket (5)
Single bracket (5)
Length
1.0 metre
1.0 metre
N/A
N/A
N/A
N/A
250mm
500mm
1000mm
2000mm
N/A
N/A
N/A
N/A
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.
15
INSTALLATION OF TWIN ADAPTOR KIT (fig. 19 & 20)
• Insert the exhaust connection manifold (A) onto the appliance
flue outlet.
• Remove the blanking plate (located to the left of the appliance
flue outlet) and – using the same screws – install the air inlet
plate (B).
• Using the hole in the exhaust connection manifold as a guide,
drill a 3mm hole in the appliance flue spigot and secure the
exhaust manifold connection to the flue spigot using the screw
provided (C).
• Using the two holes in the air inlet plate as a guide, drill a
3mm hole in each and secure the air inlet pipe/bend using
the screws provided.
The twin flue 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).
B
A
• 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 preferable 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-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 have a fall of between 1 & 3º towards the appliance (1º =17mm per 1000mm).
C
Fig. 19
1-deg = 17mm
Fig. 20
Fig. 21
HORIZONTAL TERMINATION (fig. 21)
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.
Depending on site conditions it may be preferable to install the
terminal assembly prior to fitting the twin flue pipes.
Mark and drill a level 130mm hole for the passage of the horizontal
flue terminal. 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 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.
NOTE
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.
VERTICAL TERMINATION (fig. 22)
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.
16
Fig. 22
4.6 CONNECTING THE GAS AND WATER
The appliance is supplied with an accessory pack that includes
service valves.
The service valves are of the compression type.
The accessory pack contains sealing washers’ etc, for use
with the service valves. When connecting pipe work to the valves, tighten the compression end first then insert the sealing
washers before tightening the valve to the appliance.
NOTE
It will be necessary to hold the valve with one spanner whilst
tightening with another.
Hot water outlet
Gas cock
C/H flow valve
4.6.1 GAS (fig. 24)
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 FLOW & RETURN (fig. 24)
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.
NOTE
Depending on system requirements, it may necessary to increase the size of the flow & return pipe work after the service
valve connections.
Cold water inlet
stopcock
Safety valve outlet
Fig. 24
C/H return valve
4.6.3 COLD WATER INLET (fig. 24)
The appliance is supplied with a 15mm stopcock, connect a
15mm pipe to the inlet of the stopcock and tighten both nuts.
4.6.4 HOT WATER OUTLET (fig. 24)
The appliance is supplied with a 15mm outlet connection, connect a 15mm pipe to the outlet connection and tighten both nuts.
4.6.5 SAFETY VALVE (fig. 24)
Connect the safety valve connection 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.
4.6.6 CONDENSE PIPE
During normal operation the boiler produces condense which
is collected in a trap located in the lower part of the boiler. A
flexible pipe (condense 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 3º fall towards the drain. Any external run of pipe should
be insulated to prevent the risk of freezing.
4.6.7 CONNECTING THE CONDENSATE OUTLET
Gently pull the condense outlet pipe down from its location
inside the boiler until approximately 100mm protrudes from the
underside of the boiler, care should be taken to ensure that the
pipe connection to the trap remains secure. Connect a suitable
plastic (not copper) pipe (no less than 21mm diameter) to the
outlet pipe and ensure it discharges in accordance with local
building regulations or other rules in force.
17
4.7 ELECTRICAL CONNECTIONS
The boiler is supplied with a 2-metre fly-lead. This lead can
be used for connection to the electrical supply. Connect the
fly-lead to a fused plug or fused isolator in the following way:
• brown wire to LIVE supply
• blue wire to NEUTRAL supply
• green/yellow to EARTH connection.
Insert the supplied 3-AMP fuse into the fused isolator or fused plug.
Should the fly-lead be unsuitable, refer to 4.7.3 for details on
how to connect the electrical supply directly to the boiler.
The electrical supply must be as specified in section 3/3A.
A qualified electrician should connect the appliance to the
electrical supply. 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 or
equivalent. Wiring to the appliance must be rated for operation
in contact with surfaces up to 90 ºC.
Fig. 25
4.7.1 CASING REMOVAL (fig. 25)
To gain internal access to the appliance you must first remove
the casing, proceed as outlined below:
• locate and unscrew the 2-screws (A) that secure the outer
casing to the appliance
• 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
• gently lower the control fascia until it rests.
4.7.2 APPLIANCE TERMINAL BLOCK
The appliance terminal block is located on the rear of the control fascia. Remove the casing as described in 4.7.1. Gently
pull the control panel forwards and down. Locate the terminal
block cover (fig. 26).
NOTE
The appliance comes with a factory fitted link (‘TA’) to allow
basic operation of the boiler via the mode selector switch. If it is
anticipated that external controls will be required please refer to
the wiring diagrams in section 8 for more detailed information.
4.7.3 CONNECTING THE MAINS (230V) INPUT
Unhook and remove the terminal block cover (230V). Pass the
cable through the cable anchorage point. Connect the supply
cable wires (LIVE, NEUTRAL, & EARTH) to their corresponding
terminals (L, N, & E) on the appliance – high voltage – terminal
block. When connecting the EARTH wire, ensure that it’s left
slightly longer that the others, this will prevent strain on the
EARTH wire should the cable become taut. Do not remove the
link wire unless additional external controls are to be fitted (see
section 8). The securing screw on the cable anchorage should
now be tightened. This must be done before the terminal block
cover is re-fitted in its position.
NOTE
It is the installer’s responsibility to ensure that the appliance is
properly Earthed. Vokèra Ltd. cannot be held responsible for
any damages or injuries caused as a result of incorrect Earth
wiring.
18
Fig. 26
A
SECTION 5 - COMMISSIONING
5.1 GAS SUPPLY INSTALLATION
Inspect the entire installation including the gas meter, test for
tightness and purge. Refer to BS 6891 (I.S. 813 in ROI) for
specific instruction.
5.2 THE HEATING SYSTEM
The appliance contains components that may become damaged
or rendered inoperable by oils and/or debris that are residual
from the installation of the system, consequently it is essential
that the system be flushed in accordance with the following
instructions.
5.3 INITIAL FILLING OF THE SYSTEM
Ensure both flow and return service valves are open, remove
appliance casing as described in 4.7.1, identify the automatic air
release valves (AAV) and loosen the dust cap/s by turning the
cap anti-clockwise one full turn. Ensure all manual air release
valves located on the heating system are closed. Connect the
filling loop, slowly proceed to fill the system by firstly opening
the inlet valve connected to the flow pipe, and then turning the
lever on the fill valve, to the open position. As water enters the
system the pressure gauge will begin to rise. Once the gauge
has reached 1 BAR close both valves and begin venting all
manual air release valves, starting at the lowest first. It may be
necessary to go back and top-up the pressure until the entire
system has been filled. Inspect the system for water tightness,
rectifying any leaks.
5.3.1 MANUAL AIR RELEASE (fig. 27)
When the boiler has been filled for the first time or the system
has been drained and refilled, it will be necessary to release
any air that may have become trapped within the appliance heat
exchanger. Slacken the bleed screw until water is released
and then close.
IMPORTANT, THERE ARE NO OTHER MANUAL AIR RELEASE VALVES LOCATED ON THE APPLIANCE.
•
•
•
•
(see 7.8) particularly continuity, polarity and resistance to
earth;
ensure the 3 AMP fuse – supplied with the appliance – has
been fitted;
ensure the system has been filled, vented and the pressure
set to 1 BAR;
ensure the flue system has been fitted properly and in accordance with the instructions;
ensure all appliance service valves are open.
5.6 INITIAL LIGHTING
Ensure the electrical supply to the appliance is switched on.
Ensure any external controls are switched to an ‘ON’ position
and are calling for heat. Move the selector switch to the ON
position, the appliance will now operate as described in 1.2.
Should the appliance fail to ignite, refer to 5.6 and/or section 7
(mode of operation, parameter setting & faultfinding).
5.7 CHECKING GAS PRESSURE AND COMBUSTION ANALYSIS
The appliance is factory set so should require no additional
adjustment once installed. However to satisfy the requirements
of GSIUR 26/9 (I.S. 813 ROI), it will be necessary to gas rate
the appliance using the gas meter that serves the appliance
and carry out a combustion analysis check in accordance with
BS 7967 (UK) to ensure that correct combustion is occurring,
see flow chart on page 37.
Additionally, if the gas valve has been adjusted, replaced, or the
appliance has been converted for use with another gas type,
then it becomes necessary to carry out a combustion analysis
check to ensure that correct combustion is occurring.
If there are no means to carry out a combustion analysis check,
then it will not be possible to complete the commissioning
procedure.
Details on how to carry out the combustion analysis can be
found in section 7.
IMPORTANT
It’s imperative that a sufficient dynamic – gas – pressure is
maintained at all times. Should the dynamic gas pressure fall
below an acceptable level, the appliance may malfunction or
sustain damage.
5.8 FINAL FLUSHING OF THE HEATING SYSTEM
The system shall be flushed in accordance with BS 7593 (I.S.
813 ROI). Should a cleanser be used, it must be suitable for
Aluminium heat exchangers. It shall be from a reputable manufacturer and shall be administered in strict accordance with the
manufacturers’ instructions and the DWTA code of practice.
NOTE
Chemicals used to cleanse the system and/or inhibit corrosion
must be pH neutral, i.e. they should ensure that the level of the
pH in the system water remains neutral. Premature failure of
certain components can occur if the level of pH in the system
water is out-with normal levels.
5.8.1 INHIBITORS
See Section 3 “General Requirements”.
Fig. 27
5.4 INITIAL FLUSHING OF THE SYSTEM
The whole of the heating system must be flushed both cold
and hot as detailed in 5.8. Open all radiator or heating valves
and the appliance flow & return service valve. Drain the boiler
and system from the lowest points. Open the drain valve full
bore to remove any installation debris from the boiler prior to
lighting. Refill the boiler and heating system as described in 5.3.
5.5 PRE-OPERATION CHECKS
Before attempting the initial lighting of the appliance, the following checks must be carried out:
• ensure all gas service valves from the meter to the appliance
are open and the supply pipe has been properly purged;
• ensure the proper electrical checks have been carried out,
5.9 SETTING THE FLOW OUTLET TEMPERATURE
The flow outlet temperature can be adjusted between 40 °C 80 °C for standard CH system by using the Heating thermostat
knob (see fig.1).
5.9.1 SETTING THE DHW OUTLET TEMPERATURE
The DHW outlet temperature can be adjusted between 37 °C
- 60 °C via the DHW thermostat knob (see fig.1).
5.10 SETTING THE SYSTEM DESIGN PRESSURE
The design pressure should be a minimum of 0.5 BAR and a
maximum of 1.5 BAR. The actual reading should ideally be 1
BAR plus the equivalent height in metres (0.1 BAR = 1 metre) to
the highest point in the system above the base of the appliance
(up to the maximum of 1.5 BAR total). N.B. The safety valve
19
is set to lift at 3 BAR/30 metres/45 psig. To lower the system
pressure to the required value, drain off some water from the
appliance drain valve until the required figure registers on the
pressure gauge (see fig. 1).
5.11 REGULATING THE CENTRAL HEATING
SYSTEM
Fully open all radiator and circuit valves and run the appliance
for both heating and hot water until heated water is circulating.
If conditions are warm remove any thermostatic heads. Adjust
radiator return valves and any branch circuit return valves
until the individual return temperatures are correct and are
approximately equal.
5.11.1 REGULATING THE DHW FLOW-RATE
The appliance is fitted with a flow rate restrictor that limits the
maximum flow rate that can be drawn through the appliance.
The restrictor eliminates the need to manually adjust the DHW
flow rate. However if it is felt necessary to further increase or
decrease the available flow rate, spare restrictors are available
to Vokèra spare parts.
The spare flow rate restrictors can be fitted to either increase
or decrease the maximum flow rate.
5.11.2 FLOW-RATE RESTRICTOR
The boiler is supplied with the following flow restrictor.
Compact A 25: 8 - litres flow restrictor
Compact A 29: 10 - litres flow restrictor
5.12 FINAL CHECKS
• ENSURE ALL TEST NIPPLES ON THE APPLIANCE GAS
VALVE ARE TIGHT AND CHECKED FOR TIGHTNESS.
• ENSURE THE APPLIANCE FLUE SYSTEM IS FITTED
CORRECTLY AND IS PROPERLY SECURED.
• ENSURE ALL PIPE WORK IS RE-CHECKED FOR TIGHTNESS.
• RE-FIT APPLIANCE CASING.
• COMPLETE BENCHMARK CHECKLIST.
FOR UK ONLY
Complete details of the boiler, controls, installation and commissioning in the Benchmark checklist at the back of this
book. It is important that the Benchmark checklist is correctly
completed and handed to the user. Failure to install and commission the appliance to the manufacturers instructions will
invalidate the warranty.
5.13 INSTRUCTING THE USER
Hand over all documentation supplied with this appliance –
including these instructions – and explain the importance of
keeping them 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 any
associated controls correctly.
Show the user the location of the filling valve and how to topup the system pressure correctly and show the location of all
manual air release points.
Explain to the user how to turn off the appliance for both long
and short periods and advise on the necessary precautions to
prevent frost damage.
Explain to the user that for continued safe and efficient operation,
the appliance must be serviced annually by a competent person.
IMPORTANT
To validate the appliance warranty, it’s necessary to register
the appliance details with us. The warranty can be registered
in several ways:
• by completing the warranty registration card and posting to
us using the envelope supplied
• online at: vokera.co.uk
• for UK residents by calling: 0870 607 0281
• for ROI residents by calling: 056 6655057.
SECTION 6 - SERVICING INSTRUCTIONS
6.1 GENERAL
Once the appliance has been serviced, the benchmark Service
Record must be completed.
For UK only: It is important that the Benchmark Service Record
is correctly completed and handed to the user. Failure to install
and commission the appliance to the manufacturers instructions
will invalidate the warranty.
To ensure the continued safe and efficient operation of the appliance, it is recommended that it is checked and serviced at
regular intervals. To ensure correct and safe operation of the
appliance, it is essential that any worn or failed component be
replaced only with a genuine Vokèra spare part. It should be
remembered that although certain generic components may
look similar, they will be specific to an individual appliance or
product range. Use of non-genuine Vokèra spare parts could
invalidate your warranty and may pose a potential safety hazard. The frequency of servicing will depend upon the particular
installation conditions, but in general, once per year should be
sufficient. It is the law that any servicing work is carried out by
competent person such as a Vokèra engineer, an approved
service agent, British Gas, GAS SAFE registered personnel
or other suitably qualified personnel. The following instructions apply to the appliance and its controls, but it should be
remembered that the central heating and the domestic hot
water systems would also require attention from time to time.
6.2 ROUTINE ANNUAL SERVICING
• Check the operation of the appliance and 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
20
apparatus.
• Check and adjust – if necessary – all burner pressure settings
(see 7.4).
• Check and adjust – if necessary – the system design pressure
(see 5.10).
• Carry out an analysis of the flue gases (see 7.5), and visually
check the condition of the entire flue assembly.
• Compare the results with the appliance design specification.
Any deterioration in performance must be identified and rectified without delay.
• Check that the main heat exchanger are clean and free from
any debris or obstruction.
• Check and clean – if necessary – the condense trap to ensure
correct operation.
The flame side of the burner is made of state-of-the-art material.
Being fragile:
- be particularly careful when handling, mounting or dismantling the burner and adjacent components (e.g. electrodes,
insulation panelling etc.)
- avoid direct contact with any cleaning appliance (e.g. brushes,
aspirators, blowers, etc.).
This component does not need any maintenance, please do
not remove it from its housing, save where the O-ring may have
to be replaced.
The manufacturer declines all responsibility in cases of damages
due to failing to observe the above.
6.3 REPLACEMENT OF COMPONENTS
Although it is anticipated that this appliance will give years of
reliable, trouble free service, the life span of components will be
determined by factors such as operating conditions and usage.
Should the appliance develop a fault, the fault finding section
will assist in determining which component is malfunctioning.
6.4 COMPONENT REMOVAL PROCEDURE
To remove a component, access to the interior of 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 described in
section 4.7.1 and drain the water content from the appliance
via the drain valve. Ensure some water absorbent cloths are
available to catch any residual water that may 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 TIGHTNESS IF ANY
GAS CARRYING COMPONENTS HAVE BEEN REMOVED
OR DISTURBED.
Fig. 28
6.4.1 AIR BOX FRONT COVER REMOVAL (fig. 28)
Locate the 4 screws and remove air box front cover.
A
6.5 PUMP ASSEMBLY (fig. 29)
Carry out component removal procedure as described in 6.4.
Disconnect and remove the pump outlet pipe (A) from the pump
assembly/combustion chamber connection.
Remove the expansion pipe locking pin (B) from the top of the
pump assembly and withdraw the flexible pipe. Locate and
remove the pressure gauge securing pin (C) and disconnect
the pressure gauge from the pump assembly. Disconnect the
electrical wiring from the pump’s electrical connection point (D).
Locate and remove the 2 securing screws (E) at the rear of the
pump assembly. Remove locking pin (F) from pump base and
lift pump assembly clear of the hydraulic manifold. The pump
assembly can now be removed from the appliance. Replace
carefully in the reverse order.
I
J
B
C
E
D
Fig. 29
F
G
H
L
6.6 SAFETY VALVE (fig. 30)
Carry out component removal procedure as described in 6.4.
Disconnect the outlet pipe (G) from the safety valve, remove
safety valve locking pin (H) from the hydraulic manifold. Replace
in the reverse order.
K
6.7 LOWER AUTOMATIC AIR RELEASE VALVE
(fig. 29)
Carry out component removal procedure as described in 6.4.
Remove the expansion pipe locking pin (B) from the pump assembly and remove the expansion pipe. Locate and remove
the AAV locking pin (I) from the pump assembly and remove
the AAV assembly (J). Replace in the reverse order.
Fig. 30
Fig. 31
M
6.7.1 TOP AUTOMATIC AIR RELEASE VALVE (fig. 31)
Carry out component removal procedure as described in 6.4.
Unclip and remove the air chamber front cover. Remove the
AAV locking pin (K) from the deaerator assembly and remove
the AAV assembly (L). Replace in the reverse order.
J2
I2
6.8 WATER PRESSURE SWITCH (fig. 32)
Carry out component removal procedure as described in 6.4.
Locate and remove the locking pin (M) from the water pressure
switch (N). Remove the wiring. Carefully withdraw the switch.
Replace in the reverse order.
6.9 FLOW THERMISTOR (fig. 5 - pos. 17)
N
Fig. 32
Carry out component removal procedure as described in 6.4.
Unclip and remove the air chamber front cover. Unclip the flow
thermistor from the flow outlet pipe. Disconnect thermistor
electrical plug. Replace in the reverse order.
6.10 RETURN THERMISTOR (fig. 5 - pos. 20)
O
Carry out component removal procedure as described in 6.4.
Unclip the return thermistor from the return inlet pipe. Disconnect thermistor electrical plug. Replace in the reverse order.
6.11 PRINTED CIRCUIT BOARD (fig. 33)
Carry out component removal procedure as described in 6.4.
Pull the control fascia forward and lower it. Push the clips (O)
which secure the PCB cover, remove cover, after carefully tak-
Fig. 33
21
ing note of all wiring connections and jumper tag configuration.
Unhook and remove connection block (P). Disconnect all wiring
from the PCB, locate and remove the PCB securing screws,
remove the required PCB. Replace in the reverse order ensuring that the position of the 2 control knobs are correctly aligned
with the respective potentiometers on the PCB.
Ensure that the correct jumper tag configuration has been
respected. It will be necessary to check the functioning of the
PCB is set for the correct boiler output, type and application.
Details on setting fan speeds can be found in section 7.10.
6.12 GAS VALVE (fig. 34)
S
U
Q
Fig. 34
T
Carry out component removal procedure as described in 6.4.
The gas valve must be changed as complete unit. Disconnect
the electrical plug and leads from the gas valve, slacken and
unscrew gas valve inlet and outlet connections. Please note,
the sealing washers (Q) must be discarded and replaced with
new sealing washers. Disconnect the compensation pipe (R).
Unscrew gas pipe connections (S-T), the gas valve can now
be removed. Replace in the reverse order. Check and adjust
burner pressure settings.
WARNING, A GAS TIGHTNESS CHECK MUST BE CARRIED OUT.
6.12.1 INJECTOR (fig. 34)
Carry out component removal procedure as described in 6.4.
Unscrew and remove gas pipe connections (S-T). Locate and
remove the injector (U) inside the valve. Replace in the reverse
order. Check and adjust burner pressure settings.
WARNING, A GAS TIGHTNESS CHECK MUST BE CARRIED OUT.
V
Y
W
Fig. 35
H1
6.13 ELECTRODES (fig. 35)
Carry out component removal procedure as described in 6.4.
Remove the air chamber front cover. Disconnect the electrode
leads and ancillary wiring from their respective connectors. Remove the retaining screws (V) for electrode. Remove the spark
ignition electrode (W). Remove the flame sensor electrod (Y).
Q
D1
C1
E1
6.14 FLUE FAN & MIXER (fig. 36-37)
Carry out component removal procedure as described in 6.4.
Remove the air chamber front cover. Locate and remove the
gas pipe locking pin (A1) and swing/rotate the gas pipe away
from the fan assembly (B1), (if necessary unscrew the gas
pipe from the gas valve G1). Locate and slacken the silencer
(H1). Locate and remove the sense electrode. To remove the
fan (E1), disconnect the electrical connections attached to
the fan, locate and remove the four screws (F1). Gently ease
the fan from its location. To remove the mixer (C1) locate and
remove the three screws (D1), the mixer can be removed after
the fan removal. Replace in the reverse order. Ensure all seals
are in good condition, taking care to ensure they are replaced
correctly.
F1
I1
V
Y
W
L1
K1
6.15 BURNER (fig. 36)
Carry out component removal procedure as described in 6.4.
Remove the air chamber front cover. Locate and remove the
gas pipe locking pin (A1) and swing/rotate the gas pipe away
from the fan assembly (B1), (if necessary unscrew the gas
pipe from the gas valve G1). Locate and slacken the silencer
(H1), disconnect the electrical connections attached to the
fan. Disconnect the electrode leads and ancillary wiring from
their respective connectors. Locate and remove the screws
(I1) which secure the burner assembly in position to the heat
exchanger (J1). Gently ease the fan assembly out of its location.
Once the assembly has been removed, the burner (K1) can
be withdrawn from the heat engine. Ensure the seals (L1) is in
good condition, taking care to ensure it is replaced correctly.
Replace in the reverse order.
L1
J1
Fig. 36
22
6.16 MAIN HEAT EXCHANGER (fig. 37)
Carry out component removal procedure as described in 6.4.
Remove the air chamber front cover. Locate and remove the
gas pipe locking pin (A1) and swing/rotate the gas pipe away
from the fan assembly (B1), (if necessary unscrew the gas pipe
from the gas valve G1). Disconnect the electrical connections
attached to the fan. Disconnect the electrode leads and ancillary
wiring from their respective connectors.
Disconnect the flow locking pin (M1), return locking pin (N1) on
the heat exchanger. Locate and remove the screws that secure
the heat exchanger to the combustion chamber (O1). Move the
heat exchanger and disconnect it from the flue collector (P1).
The heat exchanger can now be lifted up and withdrawn from
the appliance.
Replace in the reverse order. Ensure all seals are in good
condition, taking care to ensure they are replaced correctly.
N1
A1
B1
P1
M1
O1
G1
6.17 AUTOMATIC BY-PASS & DHW NON-RETURN
VALVE (fig. 38)
J1
Fig. 37
Carry out component removal procedure as described in 6.4.
Remove the locking pin (Q1) that secures the cover (R1) to
the hydraulic manifold. Using a hooked piece of wire, carefully
withdraw the by-pass cartridge (S1) and/or DHW non-return
cartridge (T1). Ensure all seals are in good condition, taking
care to ensure they are replaced correctly. Replace in the
reverse order ensuring the cartridge is facing the correct way.
Q1
6.18 EXPANSION VESSEL REMOVAL (fig. 39)
Carry out component removal procedure as described in
6.4. Disconnect the flexible expansion pipe from the vessel.
Unscrew the nut that secures the vessel to the lower frame.
Locate and remove the screw (U1) that secures the vessel to
the top. The expansion vessel can now be removed. Replace
in the reverse order. Ensure all seals are in good condition,
taking care to ensure they are replaced correctly.
T1
R1
Fig. 38
S1
6.19 CONDENSE TRAP REMOVAL (fig. 40)
Carry out component removal procedure as described in 6.4.
Disconnect the the locking pin (V1) that secures the trap to
the air condense pipe. Disconnect the lower rubber condense
pipe from the condense trap. Carefully remove the condense
trap. For cleaning unlock the upper and lower closing plug (W1).
Replace in the reverse order.
U1
Fig. 39
W1
V1
Fig. 40
23
6.20 FLUE COLLECTOR REMOVAL (fig. 41)
Carry out component removal procedure as described in 6.4.
Remove the air chamber front cover. Remove the heat exchanger as per 6.16. Locate and remove the screw (Y1) that secures
the flue gas analysis test point cover (Z1). Disconnect the flues
thermistor wiring connections. Locate and remove the 4 screws
(A2). Locate and remove the 2 screws (A3). Gently ease the
condensate collector (A4) out off its location. Gently ease the
flue collector out off its location. Replace in the reverse order.
Y1
Z1
6.20.1 DHW FLOW RESTRICTOR (fig. 42)
Carry out the component removal procedure as described in
6.4.
Disconnect the cold water inlet pipe at the DHW flow switch
(B2). Using a small screwdriver, gently ease the flow restrictor
(C2) from its seating. Replace in the reverse order. Ensure
all seals are in good condition, taking care to ensure they are
replaced correctly.
6.20.2 DHW FLOW SWITCH (fig. 42)
Carry out component removal procedure as described in 6.4.
Remove the locking pin (D2). Disconnect and remove the cold
water inlet pipe from the DHW flow switch & DHW heat exchanger. Disconnect the wiring to the DHW flow switch. Slacken
and unscrew the inlet connection. Unscrew the nut (E2). Lift the
DHW flow switch housing from its seating. If necessary remove
the locking pin (F2) from the DHW flow switch, taking care not
to lose the float contained within the housing.
Replace in the reverse order ensuring that the housing is firmly
inserted onto its seating. Ensure all seals are in good condition,
taking care to ensure they are replaced correctly.
6.20.3 VALVE ACTUATOR (fig. 43)
Carry out component removal procedure as described in 6.4.
Remove the locking pin (G3) that secures the actuator (H2) to
the heating manifold. Disconnect the electrical plug from the
actuator. Replace in the reverse order.
A2
A4
A3
Fig. 41
D2
C2
B2
F2
Fig. 42
E2
6.20.4 DHW THERMISTOR (fig. 32)
Carry out component removal procedure as described in 6.4.
Locate and remove the thermistor locking pin (I2). Gently ease
the thermistor assembly (J2) from the hydraulic manifold. Replace in the reverse order.
K2
6.20.5 DIVERTOR VALVE ASSEMBLY (fig. 43)
Carry out component removal procedure as described in 6.4.
Remove the valve actuator as described in 6.20.3. Locate and
remove the locking pin (G2) that secures the valve housing
cover to the hydraulic manifold. Gently prise the valve assembly from the manifold (K2). Replace in the reverse order
ensuring that the seating assembly is inserted properly. Ensure
all seals are in good condition, taking care to ensure they are
replaced correctly.
24
H2
G2
Fig. 43
G3
SECTION 7 - CHECKS, ADJUSTMENTS AND FAULT FINDING
7.1 CHECKING APPLIANCE OPERATION
When carrying out any repairs or servicing to the appliance,
the relevant commissioning procedure must be undertaken to
ensure the continued safe operation of the appliance. Particular
attention should be made to ensure gas tightness, water tightness and the electrical integrity of the appliance.
7.2 APPLIANCE MODES OF OPERATION
NOTE
There must be sufficient system water pressure (min. 0.5 bar)
to ensure the water pressure switch is activated. If there is insufficient system pressure the pump and fan will be prevented
from operating and the low-pressure fault code will be indicated.
7.2.1 SELECTOR SWITCH IN THE OFF/RESET POSITION
When the selector switch is in the OFF/RESET position, the
following functions are active.
Active functions:
• frost-protection system
• pump & actuator anti-block.
7.2.2 ON-BOARD FUNCTIONS
• CO FUNCTION: the CO function when activated, will allow the
appliance to run at CH maximum, DHW maximum or minimum
output whilst a combustion analysis check or a mechanical gas
valve calibration is being carried out. Whilst the CO function
is active, all other functions are disabled (minimum power
operating period, anti-cycle, set-point, etc). Once enabled,
the CO function will remain active for a 15-minute period, or
until the function is manually deactivated
• FROST-PROTECTION: this function is only active when
there are no requests for heating or HW. If the temperature
drops below 5°C, the boiler will operate on minimum power
until the temperature of the thermistors reaches 35°C for CH
and 55°C for DHW. Thereafter the pump & fan will over-run
for 30-seconds.
• ANTI-CYCLE FUNCTION: the anti-cycle function ensures the
burner remains switched off for at least 3-minutes after the
set-point hysterisis (set-point + 5-deg) for CH heat request.
• PUMP ANTI-BLOCK FUNCTION: when there has been no
heating or HW request for 24-hours, the anti-block cycle is
activated. The pump will be activated for a period of 30-seconds.
• ACTUATOR ANTI-BLOCK FUNCTION: when there has been
no heating or HW request for 24-hours, the anti-block cycle
is activated. The divertor valve actuator will motor briefly to
the heating position, and then back to the DHW position. The
pump will run briefly.
• SARA function: the SARA function permits the boiler (when
the set-point is within the SARA range) to automatically adjust
(raise) the heating flow outlet temperature should the room
thermostat contacts remain closed for more that 20-minutes.
 DHW PRE-HEAT FUNCTION: when the DHW pre-heat function is enabled, the appliance will light periodically to maintain
the temperature of the DHW heat exchanger. When the
DHW thermistor and the primary thermistor fall below 35°C
and 55°C respectively, the boiler will fire on minimum +25%
power until the primary thermistor exceeds 55°C. Thereafter
the pump will over-run for a period of 30-seconds.
7.2.3 HEATING MODE
With the selector switch in the heating & hot water position
and any additional controls (time clock, programmer, room
thermostat, etc.) calling for heat, the appliance will operate
in the heating mode. The pump and fan will be activated via
the flow temperature sensor. When the fan is sensed to be
operating correctly (tacho signal), the ignition sequence commences. Ignition is sensed by the electronic circuit to ensure
flame stability at the burner. Once successful ignition has been
achieved, the electronic circuitry increases the gas rate to 75%
for a period of 15 minutes.
The speed of the fan and therefore the output of the boiler is
determined by the temperature of the water sensed by the
flow temperature sensor, 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 pipe 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
(+ hysterisis), the burner will switch off. The built-in anti-cycle
device prevents the burner from re-lighting for approximately
3-minutes. When the temperature of the flow sensor falls below
the set point (- hysterisis), the burner will re-light.
NOTE
If the spark/sensing electrode does not sense ignition the appliance will re-attempt ignition a further 4-times then go to lockout.
When the set-point has been reached (the position of the heating
temperature selector) as measured at the primary thermistor, the
appliance will begin the modulation phase whereby the fan and
gas valve will continuously modulate to maintain the set-point.
If the temperature continues to rise and exceeds the set-point
by 5°C (hysterisis), the burner will shut down. A new ignition
sequence will be enabled when the 3- minute anti-cycle has
been performed and the temperature at the primary thermistor
has dropped 5°C (hysterisis) below the set-point.
7.2.4 DHW MODE
With the selector switch in either the hot water only or heating
& hot water position, the appliance will operate in the hot water
mode whenever a DHW outlet is opened. A flow rate exceeding
2-litres per minute will activate the DHW flow switch whereupon
the pump and fan will be activated via the flow temperature
sensor. When the fan is sensed to be operating correctly (tacho
signal), the ignition sequence commences. Ignition is sensed
by the electronic circuitry to ensure flame stability at the burner.
Once successful ignition has been achieved, the electronic
circuit allows the gas rate to achieve the modulation value.
NOTE
When the request for heating and/or hot water has been satisfied, the appliance pump and fan may continue to circulate to
dissipate any residual heat within the appliance.
ATTENTION
Gas type and appliance output must be set according to the
specific appliance specification. Vokèra accepts no responsibility if the gas type is not correctly adjusted according to the
respective appliance specification as detailed on the appliance
data badge.
7.3 CHECKING THE CO2 AND ADJUSTING THE
GAS VALVE
Isolate the appliance from the electrical supply and remove the
appliance casing as described in 4.7.1, to gain access to the
printed circuit board, locate and open the closing plug on the
dash board (L2), Restore the electrical supply to the boiler and
switch the boiler to the OFF mode. locate and press the CO button (see fig. 44 pos. SW1). Press the button the number of times
according the function requirement as par 7.3.1.
Set the flue gas analyser to read CO2 and insert the probe into
the flue analysis test point (Y1-Z1 fi g. 41).
L2
SW1
use the supplied
screwdriver to push the
CO botton (SW1)
Fig. 44
25
7.3.1 CO2 FUNCTION SETTINGS
Locate the CO button (see 7.3)
Select the main selector switch in position
CO2 FUNCTIONS
ACTION ON THE BUTTON
DISPLAY
ACO
ACO
ACO
combustion analysis mode
press once = burner running at maximum heating
gas valve maximun setting
press twice = burner running at maximum DHW
gas valve minimum setting
press three time = burner running at minimum
NOTE
1 - Any additional pressing of CO button after the third time the burner switched between maximum DHW and minimum.
2 - To restart the CO function it is necessary to pass throught the
position with the main selector switch
7.3.2 GAS VALVE MAXIMUM SETTING
Set the CO button at maximum (see 7.3.1), once the maximum
is obtained check that it corresponds with the appropriate CO2
value (Maximum) for the respective appliance (see 2.11). If
the CO2 reading is correct, proceed to gas valve minimum
setting (7.3.3).
However, if the CO2 reading is incorrect, the maximum gas
pressure must be adjusted as follows:
• using a 2.5mm Allen key, very slowly turn the maximum adjustment screw (see fig. 45) – clockwise to decrease, counter
clockwise to increase – until the correct value is displayed on
the CO2 analyser (allow time for the analyser to stabilise).
7.3.3 GAS VALVE MINIMUM SETTING
Set the CO button at minimum (see 7.3.1), once the minimum
is obtained check that it corresponds with the appropriate CO2
value (Minimum) for the respective appliance (see 2.11). If the
CO2 reading is correct, proceed to completion (7.3.4).
However, if the CO2 reading is incorrect, the minimum gas
pressure must be adjusted as follows:
• locate the minimum adjustment screw (fig. 45), using a suitable screwdriver remove the protection plug
• using a 4mm Allen key, very slowly turn the minimum adjustment screw (see fig. 45) - clockwise to increase, counter
clockwise to decrease - until the correct value is displayed
on the CO2 analyser (allow time for the analyser to stabilise).
7.3.4 COMPLETION
On completion of the combustion analysis check and/or any
gas valve adjustment, refit the plug (fig. 44 L2) and move the
position. Remove the test probe
mode selector throught
from the test point and refit the sealing screw/s and/or cap.
IMPORTANT
A GAS TIGHTNESS CHECK MUST BE CARRIED OUT IF ANY
GAS CARRYING COMPONENTS HAVE BEEN REMOVED,
REPLACED OR DISTURBED.
7.4 COMBUSTION ANALYSIS TEST
To carry out the combustion analysis, proceed as follows:
• Turn the function selector in OFF position
• Turn the hot water temperature selector in position
• Wait for burner ignition (about 6 seconds). The display shows
“ACO
” and the boiler operates at maximum heating
• Insert the flue gas analyser probe into the flue gas test point
(see fig. 41).
• Operate the boiler in combustion analysis mode (see 7.3.1)
and compare the values with those shown in section 2 (Nat.
Gas) or section 9 (LPG). If different adjust the gas valve according to 7.3.1, 7.3.2, & 7.3.3.
• The combustion analysis function remains active for 15
minutes, it is possible to interrupt in advance moving the
mode selector switch in desired position (
), bring
the domestic hot water temperature adjustment knob back
to the required position.
• Note: If a measured CO/CO2 ratio of 0.004/1 or less AND a
CO reading of less than 350ppm cannot be achieved, please
contact Vokera technical for advice.
26
Maximum
screw
Compensation pipe
connection
Inlet gas pressure
connection
Minimum
screw
fig. 45
7.5 CHECKING THE EXPANSION VESSEL
Carry out the component removal procedure as described in
6.4. You must ensure that the boiler is completely drained of
water. Using a suitable pressure gauge, remove dust cap on
expansion vessel and check the charge pressure. The correct charge pressure should be 1.0 bar ± 0.1 bar. If the charge
pressure is less, use a suitable pump to increase the charge.
NOTE
You must ensure the drain valve is in the open position whilst
re-charging takes place. Replace the dust cap and carry out
the relevant commissioning procedure (section 5).
7.6 EXTERNAL FAULTS
Before carrying out any faultfinding or component replacement,
ensure the fault is not attributable to any aspect of the installation.
7.6.1 INSTALLATION FAULTS
Symptom
No ignition
No hot water
No heating
Fault
Fault code
Possible cause
Check wiring/check electrical
supply
Check pipe-work
Check external controls
Possible cause
Check gas supply, check flue
system, check polarity
7.7 ELECTRICAL CHECKS
Any electrical checks must be carried out by a suitably qualified person.
7.7.1 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.
7.7.2 SHORT CIRCUIT CHECK
Isolate the appliance from the electrical supply, and using a
suitable multi-meter, carry out a short circuit test between the
Live & Neutral connections at the appliance terminal strip.
Repeat above test on the Live & Earth connections at the appliance terminal strip.
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.
7.7.3 POLARITY CHECK
With the appliance connected to the electrical supply and using a suitable multimeter, carry out the following voltage tests:
• connect test leads between the Live & Neutral connections
at the appliance terminal strip. The meter should read approximately 230V ac. If so proceed to next stage. If not, see
7.7.4.
• connect test leads between the Live & Earth connections
at the appliance terminal strip. The meter should read approximately 230V ac. If so proceed to next stage. If not, see
7.7.4.
• connect test leads between the Neutral & Earth connections at the appliance terminal strip. The meter should read
approximately 0 – 15Vac. If so polarity is correct. If not, see
7.7.4.
7.7.4 REVERSED POLARITY OR SUPPLY FAULT
Repeat the above tests at the appliance isolator, if testing
reveals correct polarity and/or supply at the isolator, re-check
wiring and connections between the isolator and the appliance.
If tests on the isolator also reveal reversed polarity or a supply
fault, consult the local electricity supplier for advice.
7.7.5 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
terminal strip. If the meter reads other than infinity there is a
fault that must be isolated, carry out a detailed continuity check
to identify the location of the fault.
These series of checks must be carried out before attempting
any faultfinding procedures on the appliance. On completion
of any task that required the disconnection and re-connection
of any electrical wiring or component, these checks must be
repeated.
7.8 FAULT FINDING
7.9 COMPONENT VALUES & CHARACTERISTICS
COMPONENT
Fan
Pump
Valve actuator
Ignition transformer
Gas valve
Room thermostat connection
NTC thermistor (dry contact)
NTC thermistor (wet contact)
VALUE
230Vac
230Vac
230Vac
230Vac
230Vac
24Vdc
10Kohm
10Kohm
FUNCTION
Standard Heating temperature
range (min – max °C)
DHW temperature
range (min – max °C)
75% maximum CH time
Heating OFF hysterisis (°C)
Heating ON hysterisis (°C)
DHW OFF hysterisis (°C)
DHW ON hysterisis (°C)
Anti-cycle delay
Pump over-run
Low output (min. output + %)
CO function max temp. (°C)
CO re-light temp. (°C)
CO function time
Flow NTC max temp. (°C)
High limit thermostat (°C)
Flue NTC max temp. (°C)
Maximum differential (°C)
VALUE
IGNITION CONTROL
Ignition attempts before L/O (lockout)
Re-ignition attempts after loss
of flame signal
VALUE
5
40 - 80
37 - 60
15 min
SP + 5
SP – 5
SP + 5
SP + 4
3-min
30-sec
Min+25
90
78
15-min
90
105
125
35
5
APPLIANCE STATUS AND FAULT CODES
When the boiler detects a temporary fault condition, the appropriate code is shown. If/when the fault is final, the pump
will perform a 60-second post circulation and fault code will be
displayed. See table on page. 4.
Before attempting any faultfinding, the electrical checks as
detailed in 7.7 must be carried out. Isolate the appliance from
the electrical supply.
Disconnect any external controls from terminal plug (CN5 fig.
39), and insert a link-wire between the two wires at the ‘TA’
connections.
NOTE
Restore the electrical supply to the boiler and turn the selector
switch to the on position. The boiler should now function as
described in section 7. Should the boiler fail to respond, the
internal fuses and connectors should be checked to ensure
integrity and continuity.
27
7.10 ADJUSTMENTS
The boiler has already been adjusted by the manufacturer
during production. If the adjustments need to be made again,
for example after extraordinary maintenance, replacement of
the gas valve, or conversion from methane gas to LPG, observe the following procedures.
The adjustment of the maximum and minimum output, and of
the maximum and minimum heating and of slow switch-on,
must be made strictly in the sequence indicated, and only by
qualified personnel only:
- disconnect the boiler from the power supply
- turn the heating water temperature selector to its maximum
- remove the casing as described in 4.7.1
- gently pull the control panel forwards and down
- locate the terminal block cover (fig. 26)
- insert the jumpers JP1 and JP3
- power up the boiler
The display shows “ADJ” for approximately 4 seconds
Next change the following parameters:
1 - Domestic hot water/absolute maximum
2 - Minimum
3 - Heating maximum
4 - Soft light fan speed
as follows:
- turn the heating water temperature selector to set the required value
- press the CO button and then skip to the calibration of the
next parameter.
Live electrical parts (230 V AC).
-
the value given in the table, use the gas valve maximum
adjustment screw
Press the “combustion analysis” button a third time to reach
the number of rotations corresponding to the minimum output (table 2)
Check the CO2 value: (table 5) if the value does not match
the value given in the table, use the gas valve minimum
adjustment screw
To exit the “combustion analysis” function, turn the control
knob
Remove the flue gas probe and refit the plug
Close the instrument panel and refit the housing.
The “combustion analysis” function is automatically deactivated if the board triggers an alarm. In the event of a fault during
the combustion analysis cycle, carry out the reset procedure.
table 1
MAXIMUM NUMBER OF
FAN ROTATIONS
METHANE
GAS (G20)
LIQUID
GAS (G31)
Compact 25A heating-DHW
49 - 61
49 - 61
rpm
Compact 29A heating-DHW
53 - 62
52 - 60
rpm
The following icons light up on the monitor:
1.
during domestic hot water/absolute maximum calibration
2.
during minimum calibration
3.
during heating maximum calibration
4. P
during soft light fan speed calibration
table 2
End the procedure by removing jumpers JP1 and JP3 to store
these set values in the memory.
THE function can be ended at any time without storing the
set values in the memory and retaining the original values as
follows:
- remove jumpers JP1 and JP3 before all 4 parameters have
been set
- set the function selector to
(OFF/RESET)
- cut the power supply
- waiting for 15 minutes after it is connected.
table 3
Calibration can be carried out without switch on the
boiler.
By turning the heating selection knob, the monitor automatically shows the number of rotations, expressed
in hundreds (e.g. 25 = 2,500 rpm).
GAS VALVE CALIBRATION
- Connect the boiler to the power supply
- Open the gas tap
(OFF/RESET) (monitor off)
- Set the function selector to
- remove the casing as described in 4.7.1
- gently pull the control panel forwards and down
- locate the terminal block cover (fig. 26)
- Press the CO button
Live electrical parts (230 V AC).
- Wait for burner ignition.
The display shows “ACO”. The boiler operates at maximum
heat output.
The “combustion analysis” function remains active for a limited time (15 min); if a delivery temperature of 90°C is reached,
the burner is switched off. It will be switched back on when
this temperature drops below 78°C.
- Insert the analyser probe in the ports provided in the air
distribution box, after removing the screws from the cover
- Press the “combustion analysis” button a second time to
reach the number of rotations corresponding to the maximum domestic hot water output (table 1)
- Check the CO2 value: (table 4) if the value does not match
28
MINIMUM NUMBER OF
FAN ROTATIONS
SOFT LIGHT FAN SPEED
METHANE
GAS (G20)
LIQUID GAS
(G31)
14
14
METHANE
GAS (G20)
LIQUID GAS
(G31)
40
40
rpm
rpm
table 4
Max. CO2
METHANE
GAS (G20)
LIQUID GAS
(G31)
9.0
10.5
METHANE
GAS (G20)
LIQUID GAS
(G31)
9.5
10.5
%
table 5
Min. CO2
%
Compact 25A
The boiler is supplied with the adjustments shown in the table. Depending on plant engineering requirements or regional flue gas emission limits it is, however,
possible to modify this value, referring to the graphs below.
HTG curve (Qnheating)
COs.a. curve (Qnheating)
6400
200
190
6000
180
5600
170
160
CO emissions s.a. (p.p.m.)
Fan rotations (rpm)
5200
4800
4400
4000
3600
3200
2800
2400
150
140
130
120
110
100
90
80
70
60
50
40
30
2000
20
1600
10
0
1200
4
4
6
8
10
12
14
16
18
20
22
24
6
8
10
12
14
16
18
20
22
24
26
26
Heat output (kW)
Heat output (kW)
Compact 29A
The boiler is supplied with the adjustments shown in the table. Depending on plant engineering requirements or regional flue gas emission limits it is, however,
possible to modify this value, referring to the graphs below.
HTG curve (Qnheating)
COs.a. curve (Qnheating)
200
6400
190
6000
180
170
5600
160
CO emissions s.a. (p.p.m.)
5200
Fan rotations (rpm)
4800
4400
4000
3600
3200
2800
2400
2000
1600
150
140
130
120
110
100
90
80
70
60
50
40
30
20
10
1200
4
6
8
10
12
14
16
18
20
22
24
26
28
30
0
4
6
8
10
12
14
18
20
REFERENCE
TEMPERATURE 15 °C
24
26
28
30
REFERENCE
TEMPERATURE 20 °C
REFERENCE
TEMPERATURE 25 °C
7.10.2 THERMOREGULATION
To set the temperature regulation curve, locate potentiometer
(P3). By turning (P3), the curve is shown on the LCD display.
ROOM TEMPERATURE CURVE OFFSET
DELIVERY TEMPERATURE (°C)
The user can adjust the temperature of the heating system
indirectly by changing the required room temperature from
between 15°C & 25°C, this will allow the PCB to recalculate
the system temperature required, the default temperature for
calculating the curve is 20°C.
The graph below can be used to determine the correct curve
setting.
22
Heat output (kW)
Heat output (kW)
7.10.1 CHECKING THE FAN SPEED
Locate the CO button (see Fig 44 pos SW1).
Select the main selector switch to the ON position, press the
CO button once, the display will then scroll through the fan
speeds along with the relevant icon.
16
90
80
70
60
50
40
30
25 ° C
20 °C
20
15 °C
10
30
25
20
15
10
5
0
-5
-10
-15
-20
EXTERNAL TEMPERATURE (°C)
Fig. 46
29
CLIMATIC CURVES
3,0
FLOW OUTLET TEMPERATURE (°C)
100
2,5
2,0
1,5
90
T80
80
70
1,0
60
0,8
50
0,6
T45
0,4
40
0,2
30
20
20
15
10
5
0
-5
-10
-15
-20
EXTERNAL TEMPERATURE (°C)
T80 Maximum set point for standard T range (JP7 removed)
T45 Maximum set point for low T range (JP7 inserted)
CN5
1
CN15
CN15
CN6
JP7 INSERTED
CN12
JP7 JP6 JP5 JP4 JP3JP2 JP1
CN8
CN7
CN8
CN7
JP7 REMOVED
CN6
CN5
JP8
JP8
P4
P4
SW1
SW1
CN13
CN13
P1
P1
CN14 P3
Fig. 47
30
1
JP7 JP6 JP5 JP4 JP3JP2 JP1
P2
CN14 P3
P2
CN12
SECTION 8 - WIRING DIAGRAMS
8.1 EXTERNAL WIRING
The appliance comes with a factory fitted (TA) link to allow
basic operation of the boiler via the mode selector switch. If
external controls are to be added to the system, they must be
connected to the appliance as shown in the following diagrams.
For advice on controls that are not featured in this book, please
contact Vokèra technical on 0844 391 0999.
MECHANICAL CLOCK RADIO FREQUENCY RECEIVER
8.1.1 EXTERNAL WIRING LIMITATIONS
Any external wiring must remain within the limits as detailed:
room thermostat = 30-metres
8.2 TYPICAL CONTROL APPLICATIONS
The appliance can be used with the following controls:
• single-channel, voltage-free time clocks (fig. 49)
• single-channel, voltage-free time clocks + room thermostats
(fig. 50)
• programmable RF room thermostats (fig. 49)
• low voltage (24Vdc) room thermostat (CN5 fig. 49)
8.3 OTHER DEVICES
Fig. 49
Contact the controls manufacturer and/or Vokèra technical
department should you require more specific information on the
suitability of a particular control. Further guidance on the recommended practice for the installation of external controls, can be
found in CHeSS – HC5/HC6 (www.energyefficiency.gov.uk).
8.4 VOKÈRA LOWER COVER MECHANICAL
CLOCK (fig. 4)
The Vokèra lower cover mechanical clock kit (product code
20025081) is entirely suitable for the Compact A range and
eliminates the need for an external time control.
The kit is comprised of the following:
• lower cover
• mechanical clock
• wiring harness
• instructions
Isolate the appliance from the electrical supply, remove the
boiler casing (see 4.7.1) and locate the factory fitted connector
plug and connect to the corresponding plug supplied with the
mechanical clock wiring harness.
To add a room thermostat, identify the 2 switch wires (black/red
colour in terminal block (CN5) and connect the room thermostat
wires in series in terminal block CN5 (see fig. 50)
Refit the boiler casing.
Fit the cover kit to the boiler.
Fig. 50
IMPORTANT
• The boiler must always be supplied with a permanent 230V
electrical supply.
• Always remove the link between TA & TA on the CN5 PCB
terminal (see fig. 49)
• The room thermostat connection is low voltage (24 Vdc)
• Do not connect any controls or auxiliary equipment to the
low-voltage terminal strip, other than that approved/supplied
by Vokèra Ltd.
31
1
2
3
AMP
4
N
F
Spark
electrode
Fuse 3.15A F
M3
GAS VALVE
P
CN12
1
2
3
4
P4
SW1
CN13
1 2 3
CN1
1 2 3 4 5
P1
D.H.W.F.S. D.H.W.T.
CN10
1
1
6
6
CN2
1
2
F Hv
3
1
CN1
12
F.T.
R.S.
-t°
-t°
F.S.
blue
blue
black
grey
grey
white
white
red
red
white
-t°
1
3
1
CN3
2
1
4
CN10 1
1
7
arancione
E.R.
CN11
FA1
CN4
AKL
Main PCB with vis medium integrated
P1
Selector switch and heating potentiometer
P2
DHW potentiometer
P3
Unused
P4
Unused
JP1
Unused
JP2
Unused
JP3
Unused
JP4
Unused
JP5
Unused
JP6
Unused
JP7
Unused
JP8
Closed - Unused
CN1-CN15 Connectors - CN5 Room thermostat (24 Vdc)
S.W.
CO2 function button
F.S. (1) Flame sensor
F1
Fuse 3.15A T
CN9
1
F
External fuse 3.15A F
M3
Terminal strip for electrical connection hight power
P
Pump
OPE
Gas valve solenoids
F Hv
Fan power supply 230 V
F Lv
Fan signal control
D.H.W.F.S Domestic hot water flow switch
D.H.W.T Domestic hot water temperature
WPS
Water pressure switch
S.E
Spark electrode
TSC2
Ignition transformer
3W
3 way motor
F.O.H.T Flow over heat thermostat
FS
Flue sensor
FT
Flow thermistor (NTC)
RS
Return thermistor (NTC)
NOTE: L-N-E connection is advisable
FA2
12
violet
violet
red
red
white
white
1
CN11
blue
CN2
1
black
brown
4
red (+)
pink (PWM)
blue (HS)
grey (-)
3.15A T
F1
blue
CN3
1
3W
3
brown
2
N
1
2
7
D.H.W.
W.P.S.
Heat
blue
blue
CN4
brown
AKL
CN9
F Lv
blue
brown
3
brown
pink
P2
CN14 P3
1
blue
1
JP8
brown
JP7 JP6 JP5 JP4 JP3JP2 JP1
CN5
blue
brown
CN15
CN6
CN7
CN8
brown
blue
yellow/green
blue
brown
F
OPE OPE
FUNCTIONAL DIAGRAM
230 V
NL
Connector
clock
F.O.HT.
Fig. 51
32
TSC2
brown
blue
red
black
SECTION 9 - LPG INSTRUCTIONS
9.1 RELATED DOCUMENTS
BS 5440
PARTS 1 & 2
FLUES & VENTILATION REQUIREMENTS
BS 5449
PART 1
FORCED CIRCULATION OF HOT WATER SYSTEMS
BS 5482
PART 1
DOMESTIC BUTANE & PROPANE GAS BURNERS IN PERMAMENT DWELLINGS
BS 5546
INSTALLATION OF GAS HOT WATER SUPPLIES FOR DOMESTIC PURPOSES
BS 6798
INSTALLATION OF BOILERS OF RATED NOT EXCEEDING 60kW
9.2 TECHNICAL DATA
Gas Pressures
Inlet pressure
Compact 25A
Compact 29A
37.0 mbar
37.0mbar
1.94
Heating maximum gas rate (kg/hr)
1.55
DHW maximum gas rate (kg/hr)
1.94
2.25
Minimum gas rate (kg/hr)
0.39
0.47
Injector size
3.9 mm
4.3 mm
Silencer flange
27 mm
29 mm
CO2 @ maximum output (%)
10.5
10.5
CO2 @ minimum output (%)
10.5
10.5
CO @ maximum output (ppm)
190
250
CO @ minimum output (ppm)
20
25
9.3 CONVERTING THE APPLIANCE GAS TYPE
To convert the appliance to another gas type it is necessary to
change the injector and adjust the gas valve (CO2).
• To change the injector see 6.12.1
• To replace the flange on the silencer see 6.15
• To adjust CO2 values see 10.6
9.4 GAS SUPPLY
The gas supply must be connected to the appliance by a competent LPG installer and must be of sufficient size to supply
the appliance at its maximum output. An existing supply must
be checked to ensure that it is of adequate size to deal with
the maximum rated input of this and any other appliances that
it serves.
9.6 CHECKING THE CO2 AND ADJUSTING THE
GAS VALVE
THE GAS VALVE MUST BE SET-UP OR ADJUSTED WITH
THE AID OF A PROPERLY CALIBRATED FLUE GAS ANALYSER.
Isolate the appliance from the electrical supply and remove
the appliance casing as described in 4.7.1. Set the flue gas
analyser to read CO2 and insert the probe into the flue analysis
test point (Y1-Z1 fig. 41). Restore the electrical supply to the
boiler and switch the boiler to the OFF mode.
Have access to the printed circuit board, locate and open the
closing plug on the dash board (L2 fig. 44), locate and press
the CO button (see fig. 44 pos. SW1). The appliance will now
operate in CO2 mode for approximately 15-minutes.
9.5 GAS SUPPLY INSTALLATION
The entire installation including the meter must be purged and
checked for gas tightness.
9 .6.1 CO2 FUNCTION SETTINGS
Locate the CO button (see 7.3)
Select the main selector switch in position
CO2 FUNCTIONS
ACTION ON THE BUTTON
DISAPLY
ACO
ACO
ACO
combustion analysis mode
press once = burner running at maximum heating
gas valve maximun setting
press twice = burner running at maximum DHW
gas valve minimum setting
press three time = burner running at minimum
NOTE
1 - Any additional pressing of CO button after the third time the burner switched between maximum DHW and minimum.
2 - To restart the CO2 function it is necessary to pass throught the
position with the main selector switch
33
10.6.2 GAS VALVE MAXIMUM SETTING
Set the CO button at maximum (see 10.3.1), once the maximum
is obtained check that it corresponds with the appropriate CO2
value (Maximum) for the respective appliance. If the CO2 reading is correct, proceed to gas valve minimum setting (10.7.2).
However, if the CO2 reading is incorrect, the maximum gas
pressure must be adjusted as follows:
• using a 2.5mm Allen key, very slowly turn the maximum adjustment screw (see fig. 45) – clockwise to decrease, counter
clockwise to increase – until the correct value is displayed on
the CO2 analyser (allow time for the analyser to stabilise).
10.6.3 GAS VALVE MINIMUM SETTING
Set the CO button at minimum (see 10.3.1), once the minimum
is obtained check that it corresponds with the appropriate CO2
value (Minimum) for the respective appliance. If the CO2 reading is correct, proceed to completion (10.7.3).
However, if the CO2 reading is incorrect, the minimum gas
pressure must be adjusted as follows:
• locate the minimum adjustment screw (fig. 37), using a suitable screwdriver remove the protection plug
• using a 4mm Allen key, very slowly turn the minimum adjustment screw (see fig. 45) - clockwise to increase, counter
clockwise to decrease - until the correct value is displayed
on the CO2 analyser (allow time for the analyser to stabilise).
10.6.4 COMPLETION
On completion of the combustion analysis check and/or any
gas valve adjustment, refit the plug (L2 j) and move the mode
position. Remove the test probe from the
selector to the
test point and refit the sealing screw/s and/or cap.
IMPORTANT
A GAS TIGHTNESS CHECK MUST BE CARRIED OUT IF ANY
GAS CARRYING COMPONENTS HAVE BEEN REMOVED,
REPLACED OR DISTURBED.
ATTENTION
Gas type and appliance output must be set according to the
specific appliance specification. Vokèra accepts no responsibility if the gas type is not correctly adjusted according to the
respective appliance specification as detailed on the appliance
data badge.
B
C
A
Fig. 52
D
Fig. 53
34
36
COMMISSIONING: CO AND COMBUSTION RATIO CHECK
BEFORE CO AND COMBUSTION RATIO CHECK
The boiler installation instructions should have been followed,
gas type verified and gas supply pressure/rate checked as
required prior to commissioning.
As part of the installation process, ESPECIALLY WHERE A FLUE
HAS BEEN FITTED BY PERSONS OTHER THAN THE BOILER
INSTALLER, visually check the integrity of the whole flue
system to confirm that all components are correctly
assembled, fixed and supported. Check that the maximum flue
lengths have not been exceeded and all guidance has been
followed (e.g. Technical Bulletin 008).
The flue gas analyser should be of the correct type, as specified
by BS 7967.
Before use, the flue gas analyser should have been maintained
and calibrated as specified by the manufacturer. The installer
must have the relevant competence for use of the analyser.
Check and zero the analyser IN FRESH AIR, as per analyser
manufacturer’s instructions.
CO AND COMBUSTION
RATIO CHECK
First verify that flue
integrity has been
visually checked in
accordance with the
“Before CO and
combustion ratio check”
box (above) before
proceeding to the “Check
CO and combustion ratio
at maximum rate” stage.
Turn off appliance and
call Vokera technical
helpline for advice.
The appliance must not
be commissioned until
problems are identified
and resolved. If
commissioning cannot be
fully completed, the
appliance must be
disconnected from the
gas supply in accordance
with the GSIUR.
NOTE: Check and record CO
and combustion ratio at both
maximum AND minimum
rate before contacting
Vokera technical.
NOTE
The air/gas ratio valve is factory-set and
must not be adjusted during commissioning
unless this action is recommended, following
contact with Vokera technical. If any such
adjustment is recommended and further
checking of the boiler is required, the
engineer must be competent to carry out
this work and to use the flue gas analyser
accordingly. If the boiler requires conversion
to operate with a different gas family (e.g.,
conversion from natural gas to LPG) separate
guidance will be provided by Vokera
technical and must be followed.
SET BOILER TO MAXIMUM
RATE
In accordance with section 7.37.4, set boiler to operate at
maximum rate (full load
condition). Allow sufficient
time for combustion to
stabilise.
CHECK CO AND COMBUSTION
RATIO AT MAXIMUM RATE
With boiler still set at maximum
rate, insert analyser probe into
flue gas sampling point. Allow
readings to stabilise before
recording.
Check all seals around the
appliance burner, internal flue
seals, door and case seals.
Rectify where necessary.
NO
NO
Is CO less than
350ppm AND
CO/CO2 ratio
less than 0.004?
Is CO less than
350ppm AND
CO/CO2 ratio less
than 0.004?
YES
NO
Is CO less than
350ppm AND
CO/CO2 ratio
less than 0.004?
YES
YES
SET BOILER TO MINIMUM RATE
In accordance with section 7.37.4, set boiler to operate at
minimum rate (to minimum
load condition). Allow sufficient
time for combustion to stabilise.
CHECK CO AND
COMBUSTION RATIO AT
MINIMUM RATE
With boiler set at minimum
rate, insert analyser probe
into flue gas sampling point.
Allow readings to stabilise
before recording.
Boiler is operating satisfactorily
No further actions required.
Ensure test points are capped, boiler case is correctly replaced and all other commissioning procedures are completed.
Complete Benchmark Checklist, recording CO and combustion ratio readings as required.
37
Cod. 20072155 - 07/13 - Ed. 1
Registered address:
Vokèra Ltd
Borderlake House
Unit 7 Riverside Industrial Estate
London Colney
Herts AL2 1HG
enquiries@vokera.co.uk
www.vokera.co.uk
www.vokera.ie
Sales, General Enquires
T 0844 391 0999
F 0844 391 0998
Vokèra Ireland
West Court, Callan
Co Kilkenny
T 056 7755057
F 056 7755060
Vokèra Limited reserve the right to change
specification without prior notice
Consumers statutory rights are not affected.
A Riello Group Company.
Company Reg No: 1047779
39
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