VOKERA Excel 25, Excel 29 User Instructions

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Page 1

Users Instructions

Installation & Servicing Instructions

THESE INSTRUCTIONS TO BE RETAINED BY USER

Vokèra is a licensed member of the Benchmark scheme which aims to improve the standards of installation and

commissioning of domestic hot water systems in the UK.

Excel

High efciency combi boiler

Excel 25 G.C. N° 47-364-12 Excel 29 G.C. N° 47-364-13

Page 2

Users instructions

Things you should know Page

1.1 Gas appliances 1

1.2 Electrical supply 1

1.3 Guarantee registration card 1

1.4 Appliance Log Book (UK only) 1

1.5 How does it work? 1

1.6 Dimensions 1

1.7 Clearances required 1

1.8 Frost protection system 1

1.9 Appliance status indicators 1

Getting started Page

2.1 Before switching ON 3

2.2 Appliance controls 3

2.3 Lighting the boiler 3

2.4 Adjusting the heating temperature 3

2.5 Adjusting the hot water temperature 3

2.6 Explanation of features 3

2.7 Automatic temperature control 3

How to... Page

3.1 How to top-up the system pressure 3

3.2 How to reset the appliance 3

3.3 How to shut down the system for short periods 3

3.4 How to shut down the system for long periods 3

3.5 How to care for the appliance 3

What if... Page

4.1 What if I suspect a gas leak 4

4.2 What if I have frequently top-up the system 4

4.3 What if the appliance is due its annual service 4

4.4 What if I need to call an engineer 4

Setting the Vokèra Page

5.1 Setting the Vokèra mechanical clock 4

Installation and Servicing instructions

Design principles & operating sequence Page

1.1 Principle components 6

1.2 Mode of operation (at rest) 6

1.3 Mode of operation (heating) 6

1.4 Mode of operation (Hot water) 6

1.5 Safety devices 6

Technical data Page

2.1 Central heating 7

2.2 Domestic hot water 7

2.3 Gas pressures 7

2.4 Expansion vessel 7

2.5 Dimensions 7

2.6 Clearances 7

2.7 Connections 7

2.8 Electrical 7

2.9 Flue details (concentric) 7

2.9A Flue details (twin pipes) 7

2.9B Flue details (80/125) 7

2.10 Efciency 7

2.11 Emissions 7

2.12 Pump duty 8

General requirements (UK) Page

3.1 Related documents 9

3.2 Location of appliance 9

3.3 Gas supply 9

3.4 Flue system 9

3.5 Air supply 9

3.6 Water circulation 9

3.7 Electrical supply 10

3.8 Mounting on a combustible surface 10

3.9 Timber framed buildings 10

3.10 Inhibitors 10

3.11 Showers 10

General requirements (EIRE) Page

3A.1 Related documents 10

3A.2 Location of appliance 10 3A.3 Gas supply 10 3A.4 Flue system 10 3A.5 Air supply 11 3A.6 Water circulation 11 3A.7 Electrical supply 11 3A.8 Mounting on a combustible surface 11 3A.9 Timber framed buildings 11 3A.10 Inhibitors 11 3A.11 Showers 11 3A.12 Declaration of conformity 11

Installation Page

4.1 Delivery 12

4.2 Contents 12

4.3 Unpacking 12

4.4 Preparation for mounting the appliance 12

4.5 Fitting the ue 12

4.6 Connecting the gas & water 15

4.7 Electrical connections 16

Commissioning Page

5.1 Gas supply installation 17

5.2 The heating system 17

5.3 Initial lling of the system 17

5.4 Initial ushing of the system 17

5.5 Pre-operation checks 17

5.6 Initial lighting 17

5.7 Checking gas pressure & combustion analysis 17

5.8 Final ushing of the heating system 17

5.9 Setting the boiler operating temperature 17

5.10 Setting the system design pressure 17

5.11 Regulating the central heating system 18

5.12 Final checks 18

5.13 Instructing the user 18

Servicing Page

6.1 General 18

6.2 Routine annual servicing 18

6.3 Replacement of components 18

6.4 Component removal procedure 18

6.5 Pump assembly 19

6.6 Safety valve 19

6.7 Lower automatic air release valves 19

6.8 Water pressure switch 19

6.9 Flow thermistor 19

6.10 Return thermistor 19

6.11 Printed circuit board 19

6.12 Gas valve 20

6.13 Electrodes 20

6.14 Flue fan & mixer 20

6.15 Burner 20

6.16 Main heat exchanger 21

6.17 Automatic by-pass & DHW non-return valve 21

6.18 Expansion vessel removal 21

6.19 Condense trap removal 21

6.20 Flue collector removal 22

Checks, adjustments and fault nding Page

7.1 Checking appliance operation 23

7.2 Appliance modes of operation 23

7.3 Checking the CO2 & adjusting the valve 23

7.4 Combustion analysis test 24

7.5 Checking the expansion vessel 24

7.6 External faults 24

7.7 Electrical checks 24

7.8 Fault nding 25

7.9 Component values & characteristics 25

Wiring diagrams Page

8.1 External wiring 26

8.2 Typical control applications 26

8.3 Other devices 26

8.4 Vokèra lower cover mechanical clock 26

L.P.G. instructions Page

10.1 Related documents 28

10.2 Technical data 28

10.3 Converting the appliance gas type 28

10.4 Gas supply 28

10.5 Gas supply installation 28

10.6 Checking the CO2 and adjusting the gas valve 28

Benchmark 30-31

Page 3

USERS INSTRUCTIONS

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 tted.

Warning: this appliance must be earthed!

1.3 GUARANTEE REGISTRATION CARD

Please take the time to ll out your guarantee registration card.

The completed warranty card should be posted within 30 days of installation.

1.4 APPLIANCE COMMISSIONING CHECKLIST (UK only)

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.

1.5 HOW DOES IT WORK?

Your Excel 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 tted. 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 Excel 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.

Dear Customer

Your Vokèra Excel 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 efciency.

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.

INTRODUCTION

1.6 DIMENSIONS

1.7 CLEARANCES REQUIRED

1.8 FROST PROTECTION SYSTEM

The Excel 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 5

C 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.

1.9 APPLIANCE STATUS INDICATORS

Your boiler is equipped with 3 status LED indicators, the Green

LED indicates that the ame is present, the Red LED indicates

the appliance has detected a fault, whilst the Yellow LED indicates that there is Servicing operation in progress.

1. THINGS YOU SHOULD KNOW

Excel 25-29

HEIGHT 715 mm

WIDTH 405 mm

ABOVE 150 mm

BELOW 150 mm

LEFT SIDE 12 mm

RIGHT SIDE 12 mm

FRONT 600 mm

Page 4

Fig. 1

BOILER STATUS LED

Green LED Boiler is working/responding to a heating/hot water request Red LED Boiler has identied a fault and has failed-safe. Refer to instructions on how to reset Yellow LED Service operation

DHW 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:

MODE SELECTOR

SWITCH

RED LED

GREEN LED

HEATING

TEMPERATURE

SELECTOR

HYDROMETRE

DHW

TEMPERATURE

SELECTOR

YELLOW LED

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 heating outlet temperature, or counter-clockwise to reduce the temperature (range: 37°C-60°C)

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

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 position 5 and 7.

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 efcient operation of the appliance is 0.5 BAR. Should the pressure fall below 0.5 BAR, the

boiler may lockout.

correct

pressure

value

Page 5

2.1 BEFORE SWITCHING ON

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 tted);

- any external thermostats and their functions;

- the appliance controls.

2.2 APPLIANCE CONTROLS (see g. 1)

The appliance controls are situated on the lower front of the appliance. The appliance controls include:

- pressure gauge;

- appliance mode selector;

- temperature selector;

- burner ON mode (green);

- fault indicator (red);

- servicing mode indicator (yellow)

- optional integral time clock/programmer (if tted).

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 ows from your hot water taps. The temperature range is

adjustable between 40

C and 80oC for the central heating, and

between 37

C and 60oC for the hot water.

The 3 LED normally shows the operating temperature of the appliance. When the status indicator (Green) is lit it indicates that the

ame is present and the burner is ON.

When the fault indicator (Red) is lit it indicates that the appliance

has identied a possible fault and performed a safety lockout.

When the fault indicator (Yellow) is lit it indicates that there is a Servicing operation in progress. The integral time clock (when tted) can be used to switch the heating on and off at pre-determined intervals.

2.3 LIGHTING THE BOILER

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 satised, the appliance will switch

off automatically.

2.4 ADJUSTING THE HEATING 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 40°C to a maximum of 80°C (if standard CH mode is selected).

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 sufciently hot enough, it may be necessary to reduce the ow 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 Excel 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 4 and 6 sector) to automatically adjust (raise) the heating. The activation and the disable of the function is visualized by blinking the green led.

2. GETTING STARTED

3.1 HOW TO TOP-UP THE SYSTEM PRESSURE

(g. 1-2)

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 lling valve connections (usually beneath the boiler, see g. 2).

- Attach the lling loop to both connections.

- Open the lling valve slowly until you hear water entering the

system.

- Close the lling valve when the pressure gauge (on the boiler) reads between 1 and 1.5 BAR (see g. 1).

- Remove the lling loop from the connections.

3.2 HOW TO RESET THE APPLIANCE

When the red fault LED is illuminated, 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 g. 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. HOW TO...

Fig. 2

control

valve

temporary

connection

control

valve

supply pipe

double

check valve

ow/return

pipe

3.3 HOW TO SHUT DOWN THE SYSTEM FOR SHORT PERIODS

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.

3.4 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.

Page 6

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 ofce.

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 tenants only

Your landlord should arrange for servicing.

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.

APPLIANCE STATUS LED AND FAULT CODES

Fig. 3

4. WHAT IF...

5. SETTING THE VOKÈRA...

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.

Alarm type Led RED Led YELLOW Led GREEN Action

Purge cycle mode active NA BLINKING BLINKING BLINKING

Alarm high limit thermostat Final BLINKING OFF OFF Reset appliance.

Call engineer if fault re-occurs

Alarm system water pressure Final ON OFF ON Check/refill system pressure,

reset, check. Call engineer if fault re-occurs.

Alarm safety shutdown and/or Final internal

fault

ON OFF OFF Reset appliance.

Call engineer if fault re-occurs.

Temporary fault Temporary OFF OFF BLINKING None

Service operation NA OFF BLINKING OFF None

Flame ON NA OFF OFF ON None

Fault sensors Final BLINKING OFF BLINKING Reset appliance.

Call engineer if fault re-occurs

Boiler stand-by NA OFF OFF BLINKING None

AUTO

OFF

Page 7

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 Excel comprises a range of high-efciency combination

boilers with outputs to DHW of 25kW and 29kW respectively. These appliances – by design – incorporate electronic ignition,

circulating pump, expansion vessel, safety valve, pressure gauge and automatic by-pass.

The Excel range is produced as room sealed, category II2H3P appliances, suitable for internal wall mounting applications only.

Each appliance is provided with a fan powered ue outlet with

an annular co-axial combustion air intake that can be rotated

– horizontally – through 360 degrees for various horizontal or vertical applications. The Excel can also be used with the

Vokèra twin ue system. The Excel is approved for use with C13 & C33 type ue ap-

plications. 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.

Fig. 4

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 ow switch

R Heating return connection F Heating ow connection

G Gas connection O Hot water outlet I Cold water inlet

INTRODUCTION

INSTALLATION AND SERVICING INSTRUCTIONS

R F G O I

Page 8

1.1 PRINCIPLE COMPONENTS

• 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 ame supervision

• Integral high-head pump

• Fan

• Expansion vessel

• Water pressure switch

• Flue sensor

• Pressure gauge

• Safety valve

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 ame 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 satised 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 ame 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 satised the appliance

pump and fan may continue to operate to dissipate any residual heat within the appliance.

Fig. 5

Expansion

vessel

Safety

valve

Pump

Return

temperature

sensor

Main heat

exchanger

Bottom

AAV

Pressure

switch

DHW heat exchanger

Diverter

valve

Drain valve

DHW tem-

perature

sensor

Flow temperature

sensor

Top AAV

Automatic

by-pass

DHW

non return

valve

return

ow

DHW

inlet

DHW outlet

Flow regu-

lator

DHW ow

switch

SECTION 1 - DESIGN PRINCIPLES AND OPERATING SEQUENCE

1.5 SAFETY DEVICES

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;

• ame sensor that will shut down the burner when no ame

signal is detected;

• ue sensor;

• a safety valve which releases excess pressure from the

primary circuit.

Page 9

2.1 Central Heating Excel 25 Excel 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 ow rate 350 l/h

2.2 Domestic Hot Water Excel 25 Excel 29

Heat input (kW) 25.00 29.00

Flow Rate: ΔT35°C 10.20 l/min 12.0 l/min

Maximum inlet pressure 6 bar

Minimum inlet pressure 0.15 bar

Minimum ow rate 2 l/min

2.3 Gas Pressures Excel 25 Excel 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 ange (ø mm) (tted) 31 -

2.4 Expansion Vessel Excel 25 Excel 29

Capacity 8 litres

Maximum system volume 74 litres

Pre-charge pressure 1 bar

2.5 Dimensions Excel 25 Excel 29

Height (mm) 715

Width (mm) 405

Depth (mm) 250

Dry weight (kg) 28 29

2.6 Clearances Excel 25 Excel 29

Sides 12mm

Top 150mm from casing or 25mm above ue elbow (whichever is applicable)

Bottom 150mm

Front 600mm

2.7 Connections Excel 25 Excel 29

Flow & return 22mm

Gas 15mm

DHW hot & cold 15mm

Safety valve 15mm

Condense

21mm

2.8 Electrical Excel 25 Excel 29

Power consumption (Watts) 11 0 119

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) Excel 25 Excel 29

Maximum horizontal ue length (60/100mm) 5.85m 4.85m

Maximum vertical ue length (60/100mm) 6.85m 5.85m

2.9A Flue Details (concentric 80-125) Excel 25 Excel 29

Maximum horizontal ue length (80/125mm) 15.3m 12.8m

Maximum vertical ue length (80/125mm) 20.3m

17.8m

2.9B Flue Details (twin pipes) Excel 25 Excel 29

Maximum horizontal ue length (80mm/80mm) 45m/45m 40m/40m

Maximum vertical ue length (80mm/80mm) 45m/45m 40m/40m

SECTION 2 - TECHNICAL DATA

Page 10

2.10 Efciency Excel 25 Excel 29

SEDBUK (%) 90.0 90.2

2.11 Emissions Excel 25 Excel 29

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

NOx rating class 5 class 5

Fig. 6

2.12 PUMP DUTY

Fig. 6 shows the ow-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 20

C temperature differential.

Fig. 7

Flow rate (l/h)

Residual head (x 100 mbar)

1st speed

2nd speed

3rd speed

0,0

0,5

1,0

1,5

2,0

2,5

3,0

3,5

4,0

4,5

5,0

0 100 200 300 400 500 600 700 800 900 1000

Key Location Minimum distance

A Below an opening (window, air-brick, etc.) 300 mm B Above an opening (window, air-brick, etc.) 300 mm C To the side of an opening (window, air-brick, etc.) 300 mm D Below gutter, drain-pipe, etc. 25 mm E Below eaves 25 mm F Below balcony, car-port roof, etc. 25 mm

G To the side of a soil/drain-pipe, etc. 25 mm (60mm for 80/125 - 5” ue) H From internal/external corner 25 mm (60mm for 80/125 - 5” ue)

I Above ground, roof, or balcony level 300 mm J From a surface or boundary facing the terminal 600 mm K From a terminal facing a terminal 1200 mm L From an opening in the car-port into the building 1200 mm M Vertically from a terminal on the same wall 1500 mm N Horizontally from a terminal on the same wall 300 mm P From a structure to the side of the vertical terminal 300 mm

Q From the top of the vertical terminal to the roof ashing As determined by the xed collar

of the vertical terminal

R To the side of a boundary 300 mm

S To the side of an opening or window on a pitched roof 600 mm T Below an opening or window on a pitched roof 2000 mm V From a vertical terminal to an adjacent opening (window, air-brick, etc.) (call Vokera technical for advice) W From a vertical terminal to an adjacent vertical terminal 300 mm (only if both terminals are the same hight)

Page 11

SECTION 3 - GENERAL REQUIREMENTS (UK)

This appliance must be installed by a competent person in ac-

cordance with the Gas Safety (Installation & Use) Regulations.

3.1 RELATED DOCUMENTS

The installation of this boiler must be in accordance with the

relevant requirements of the Gas Safety (Installation & Use) Regulations, the local building regulations, the current I.E.E.

wiring regulations, the bylaws of the local water undertaking,

the Building Standards (Scotland) Regulation and Building Standards (Northern Ireland) Regulations.

It should be in accordance also with any relevant requirements of the local authority and the relevant recommendations of the following British Standard Codes of Practice.

3.2 LOCATION OF APPLIANCE

The appliance may be installed in any room or internal space, although particular attention is drawn to the requirements of the current I.E.E. wiring regulations, and in Scotland, the

electrical provisions of the Building Regulations, with respect

to the installation of the appliance in a room or internal space containing a bath or shower.

BS 5440 PART 1 FLUES BS 5440 PART 2 FLUES & VENTILATION

BS 5449 PART 1 FORCED CIRCULATION HOT WATER SYSTEMS BS 5546 INSTALLATION OF GAS HOT WATER SUPPLIES FOR DOMESTIC PURPOSES BS 6798 INSTALLATION OF BOILERS OF RATED INPUT NOT EXCEEDING 60kW BS 6891 LOW PRESSURE INSTALLATION PIPES BS 7074 PART 1 APPLICATION, SELECTION, AND INSTALLTION OF EXPANSION VESSELS AND ANCILLARY EQUIPMENT FOR SEALED WATER SYSTEMS

BS 5440 Part 1, when the terminal is 0.5 metres (or less) below plastic guttering or 1 metre (or less) below painted eaves.

3.5 AIR SUPPLY

The following notes are intended for general guidance only.

This appliance is a room-sealed, fan-ued boiler, consequently

it does not require a permanent air vent for combustion air supply. When installed in a cupboard or compartment, ventilation for cooling purposes is also not required.

3.6 WATER CIRCULATION

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

3.6.1 PIPEWORK

It is recommended that copper tubing to BS 2871 Part 1 is used in conjunction with soldered capillary joints. Where possible pipes should have a gradient to ensure air is carried naturally to

air release points and that water ows 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 oors, 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 lling 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 sufcient, 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 lling of the system and replacing water lost

during servicing etc. directly from the mains supply, is provided

(see g. 8). This method of lling 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 g. 8.

3.6.7 LOW PRESSURE SEALED SYSTEM

An alternative method of lling 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 g. 9). The cold feed from the make-up vessel or tank must be tted

with an approved non-return valve and stopcock for isolation purposes. The feed pipe should be connected to the return pipe as close to the boiler as possible.

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 ue 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 specically for this purpose. An

existing compartment/cupboard may be utilised provided that it is modied 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. Instal-

lation pipes must be tted 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

is likely to cause a nuisance (see g. 7). 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 at roofs)

the terminal must be protected by a guard of durable material.

The guard must be tted centrally over the terminal. Refer to

Page 12

This appliance must be installed by a competent person in

accordance with and dened by, the Standard Specication

(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 ue 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-

SECTION 3A - GENERAL REQUIREMENTS (EIRE)

3.6.8 FREQUENT FILLING

Frequent lling 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.

3.7 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.

3.8 MOUNTING ON A COMBUSTIBLE SURFACE

If the appliance is to be tted on a wall of combustible material,

There is no requirement to protect the wall.

3.9 TIMBER FRAMED BUILDINGS

If the appliance is to be tted in a timber framed building, it should be tted in accordance with the Institute of Gas Engineers publication (IGE/UP/7) ‘Guide for Gas Installations in Timber

Frame Buildings’.

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.

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.

ow/return

pipe

control

valve

temporary

connection

control

valve

supply

pipe

double

check valve

Fig. 8

Fig. 9

Make-up vessel or tank

Automatic air-vent

Non-return

valve

Stopcock

5.0 metres minimum

Heating return

signed and constructed specically for this purpose. An existing compartment/cupboard may be utilised provided that it is

modied 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. Instal-

lation pipes must be tted 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 at roofs)

Page 13

the terminal must be protected by a guard of durable material.

The guard must be tted 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-ued 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.6 WATER CIRCULATION

Specic recommendations are given in I.S. 813. The following

notes are for general guidance only.

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 ows

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 oors, 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 lling 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 sufcient, 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 lling of the system and replacing water lost during servicing etc. is provided (see g. 8). You should ensure this method of lling complies with the local water authority

regulations.

3A.6.7 LOW PRESSURE SEALED SYSTEM

An alternative method of lling 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 g. 9). The cold feed from the make-up vessel or tank must be tted with an approved

non-return valve and stopcock for isolation purposes. The feed pipe should be connected to the return pipe as close to the boiler as possible.

3A.6.8 FREQUENT FILLING

Frequent lling 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.

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

If the appliance is to be tted on a wall of combustible material,

There is no requirement to protect the wall.

3A.9 TIMBER FRAMED BUILDINGS

If the appliance is to be tted in a timber framed building, it should be tted 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 specic

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 dened 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.

Page 14

Fig. 11

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 oor 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.

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.

4.4 PREPARATION FOR MOUNTING THE APPLIANCE

The appliance should be mounted on a smooth, vertical, noncombustible 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 g. 10) and ue-hole (if applicable).

4.5 FITTING THE FLUE

The top ue outlet permits both horizontal and vertical ue applications to be considered, alternatively, the Vokèra twin ue system can be utilised if longer ue runs are required.

4.5.1 CONCENTRIC HORIZONTAL FLUE

(For concentric vertical ue, see 4.5.2). (For twin ue applications, see 4.5.3).

The appliance can be used with either the Vokèra condensing

60/100mm concentric ue system or the optional 80/125mm concentric ue system.

NOTE These instructions relate only to the Vokèra condensing

60/100mm concentric ue system. For specic details on the installation of the 80/125mm concentric ue system please refer to the instructions supplied. The appliance ue outlet elbow can be rotated through 360º on its vertical axis. In addition the ue

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 ue length for each bend

45º bend 1.0 metre (60/100) - 1.0 metre (80/125)

90º bend 1.0 metre (60/100) - 1.5 metre (80/125)

Horizontal ue terminals and accessories

Part No. Description Length

29450120 Horizontal ue kit 900mm 29450121 Telescopic ue kit 455/630mm

522 Plume management kit 1370mm 29450123 90-degree bend N/A 29450124 45-degree bends (pair) N/A 29450125 500mm extension 500mm

29450126 1000mm extension 1000mm 29450127 2000m extension 2000mm 29450128 Telescopic extension 372/519mm 529 Wall bracket pack (5) 208mm

Using the template provided (A), mark and drill a 125mm hole for the passage of the ue pipe. The hole should be drilled to ensure any condense uid that forms, is allowed to drain back to the appliance (see g. 12). The xing holes for the wall-mounting

bracket should now be drilled and plugged, an appropriate type

and quantity of xing 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.

FITTING THE TELESCOPIC HORIZONTAL FLUE KIT

In some instances It may necessary to cut the inner 60mm pipe

of the ue bend at the point indicated (g.12a pos. A) to allow for easier insertion to the boiler ue spigot.

FITTING THE HORIZONTAL FLUE KIT

Carefully measure the distance from the centre of the appliance

ue outlet to the edge of the nished outside wall (dimension

X). Add 65mm to dimension X to give you Dimension Y (see

g 12). Measure dimension Y from the terminal end of the concentric ue pipe and cut off the excess ensuring any burrs are removed. Pass the concentric ue pipe through the previously drilled hole. Fit the ue bend to the boiler ue outlet and insert the concentric ue pipe into the ue bend ensuring the correct seal is made. Using the clamp, gasket, and screws supplied, secure the ue bend to the appliance ue spigot.

NOTE

Fit the internal (white) trim to the ue assembly prior to connecting the ue pipe to the bend. You must ensure that the entire ue system is properly supported and connected. Seal the ue assembly to the wall using

cement or a suitable alternative that will provide satisfactory

weatherproong. The exterior trim can now be tted.

SECTION 4 - INSTALLATION

Fig. 10

Terminal or extension

Outer clamps

Page 15

Fig.12a

EXTENDING THE FLUE

Connect the bend – supplied with the terminal kit – to the top

of the boiler using clamp (supplied) see g. 11. The additional bends & extensions have push-t connections, care should be

taken to ensure that the correct seal is made when assembling

the ue system. Connect the required number of ue extensions or bends (up to the maximum equivalent ue length) to the ue terminal (see g. 11-14). The ue system should have

a minimum of 1º; maximum of 3º rise from the boiler to outside,

to ensure any condense uid 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 g. 11-14). Remove any burrs, and check that all seals are located properly. You must ensure that the entire ue system is properly supported and connected. Seal the ue assembly to

the wall using cement or a suitable alternative that will provide

satisfactory weatherproong. The interior and exterior trim can now be tted.

4.5.2 CONCENTRIC VERTICAL FLUE

The appliance can be used with either the Vokèra condensing

60/100mm concentric ue system or the optional 80/125mm concentric ue system.

NOTE These instructions relate only to the Vokèra condensing

60/100mm concentric ue system. For specic details on the installation of the 80/125mm concentric ue system please refer

to the instructions supplied.

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

Reduction for bends

Bend Reduction in maximum ue length for each bend

45º bend 1.0 metre (60/100) - 1.0 metre (80/125)

90º bend 1.0 metre (60/100) - 1.5 metre (80/125)

Vertical ue terminal and accessories

Part No. Description Length

29450122 Vertical ue terminal 1000mm 531 Pitched roof ashing plate N/A 532 Flat roof ashing plate N/A

29450123 90-degree bend N/A 29450124 45-degree bends (pair) N/A 29450125 500mm extension 500mm 29450126 1000mm extension 1000mm 29450127 2000mm extension 2000mm 29450128 Telescopic extension 372/519mm

529 Wall bracket pack (5) 208mm

Using the dimensions given in g. 12 as a reference, mark and

cut a 125mm hole in the ceiling and/or roof.

Fig. 12b

Fig. 12c

Fit the appropriate ashing plate to the roof and insert the vertical ue terminal through the ashing plate from the outside, ensuring that the collar on the ue terminal ts over the ashing. The xing holes for the wall-mounting bracket should now be drilled and plugged, an ‘appropriate type and quantity of xing

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.

Fig. 12

Page 16

IMPORTANT

The vertical ue 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 ue assembly to the boiler ue spigot using the 100mm clip, gasket & screws (supplied), ensuring the

correct seal is made. The ue support bracket (supplied with the vertical ue kit) can now be tted. If the vertical ue requires extension/s or additional bend/s, connect the required number of ue extensions or bends (up to the maximum equivalent ue length) between the boiler and vertical ue assembly (see g. 14). Ensure that any horizontal sections of the ue 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 exten-

sion. Remove any burrs, and check that any seals are located

properly. You must ensure that the entire ue system is properly supported and connected.

4.5.3 TWIN FLUE SYSTEM

The Vokèra twin ue system enables greater ue distances to be achieved than that of a concentric ue system. It can be

used for horizontal or vertical applications, however the twin

ue system must be converted to the dedicated concentric ue kit for termination. It is essential that the installation of the twin ue system be carried out in strict accordance with these

instructions.

GUIDANCE NOTES ON TWIN FLUE INSTALLATION

• The ue 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 ue 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 ue system is adequately supported,

use at least one bracket for each extension.

• The entire ue system must be adequately insulated to maintain heat within the ue system thereby reducing the

possibility of condensate production.

• As the exhaust outlet pipe can reach very high temperatures

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

• The condensate drain pipe must be connected in accordance

with building regulations.

Reduction for bends

Twin ue accessories

Part No. Description Length

0225805 Horizontal ue terminal 1.0 metre 0225810 Vertical ue terminal 1.0 metre

359 Twin adapter kit N/A

531 Pitched roof ashing plate N/A 532 Flat roof ashing plate N/A

0225815 Condensate drain kit N/A 0225820 0.25m extension (pair) 250mm 0225825 0.5m extension (pair) 500mm 0225830 1.0m extension (pair) 1000mm 0225835 2.0m extension (pair) 2000mm 0225840 45º bend (pair) N/A 0225845 90º bend (pair) N/A 0225850 Twin bracket (5) N/A

0225855 Single bracket (5) N/A

MOUNTING THE BOILER

The xing holes for the wall-mounting bracket should now be drilled and plugged, an appropriate type and quantity of xing

should be used to ensure that the bracket is mounted securely.

Fig. 13a

HORIZONTAL TERMINATION (g. 13c)

The twin ue system must be converted to the dedicated concentric ue 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 tting the twin ue pipes.

Mark and drill a level 130mm hole for the passage of the horizontal

ue terminal. Insert the terminal assembly into the ue hole. Push-t the twin ue 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 ue pipes to

allow connection to the concentric to twin converter.

NOTE

Before cutting twin ue pipes ensure allowances have been

made for connection onto the previous piece and onto the con-

centric to twin converter. The last twin ue pipes must be pushed

50mm onto the male spigots of the concentric to twin converter.

NOTE

Seal the ue terminal assembly to the wall using cement or a

suitable alternative that will provide satisfactory weatherproof-

ing. The interior and exterior trim can now be tted.

VERTICAL TERMINATION (g. 14)

The twin ue system must be converted to the dedicated concentric ue kit for termination.

• The vertical terminal is supplied with a built-in converter box

and cannot be shortened.

Once the bracket has been secured to the wall, mount the appliance onto the bracket.

INSTALLATION OF TWIN ADAPTOR KIT (g. 13a-13b)

• Insert the exhaust connection manifold (A) onto the appliance ue outlet.

• Remove the blanking plate (located to the left of the appliance ue 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 ue spigot and secure the exhaust manifold connection to the ue 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 ue 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).

Bend Reduction in maximum ue length for each bend

45º bend 1.0 metre

90º bend 1.5 metre

Fig. 13b

Page 17

• 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 tting the twin ue pipes. Fit the appropriate ashing plate to the roof and insert the vertical ue terminal through the ashing plate from the outside, ensuring that the collar on the ue terminal ts over the ashing. Push-t the twin ue 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 ue pipes to

allow connection to the concentric to twin converter.

NOTE

• Before cutting twin ue pipes ensure allowances have been

made for connection onto the previous piece and onto the

concentric to twin converter. The last twin ue pipes must be

pushed 50mm onto the male spigots of the concentric to twin converter.

• You must ensure that the entire ue system is properly supported and connected.

• Ensure that any horizontal sections of pipe have a 1º fall

towards the appliance (17mm per 1000mm).

Fig. 13c

Fig. 14

4.6 CONNECTING THE GAS AND WATER

The appliance is supplied with an accessory pack that includes service valves. The service valves are for welding. The accessory pack contains sealing washers’ etc, for use with the service valves.

NOTE

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

4.6.1 GAS (g. 16)

The appliance is supplied with a 22mm service valve, connect a 22mm 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 (g. 16)

The appliance is supplied with 22mm service valves for the

ow 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 in-

crease the size of the ow & return pipe work after the service

valve connections.

4.6.3 COLD WATER INLET (g. 16)

The appliance is supplied with a 15mm combined stopcock and double check-valve, connect a 15mm pipe to the inlet of the stopcock and tighten both nuts.

4.6.4 HOT WATER OUTLET (g. 16)

The appliance is supplied with a 15mm outlet connection, connect a 15mm pipe to the outlet connection and tighten both nuts.

1-deg = 17mm

Fig. 15

Page 18

4.6.5 SAFETY VALVE (g. 16)

Connect the safety valve connection pipe to the safety valve outlet. Connect a discharge pipe to the other end of the safety valve connection pipe 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

exible pipe (condense outlet pipe) is connected to the outlet of the trap. The exible 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

Connect the exible condense outlet pipe supplied in the carton

to the condense trap inside the boiler, care should be taken to ensure that the trap connections are not disturbed. Connect a suitable plastic (not copper) pipe (no less than 20mm diameter) to the outlet pipe and ensure it discharges in accordance with building regulations or other rules in force.

4.7 ELECTRICAL CONNECTIONS

The boiler is supplied with a 2-metre y-lead. This lead can

be used for connection to the electrical supply. Connect the

y-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 y-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 specied in section 3/3A. A qualied 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 exible 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.

4.7.1 CASING REMOVAL (g. 17)

To gain internal access to the appliance you must rst 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-t in

the reverse order

• gently lower the control fascia until it rests.

Fig. 16

4.7.2 APPLIANCE TERMINAL BLOCK

The appliance terminal block is located on the rear of the con-

trol fascia. Remove the casing as described in 4.7.1. Gently

pull the control panel forwards and down. Locate the terminal

block cover (g. 18).

NOTE

The appliance comes with a factory tted connector plug to

allow Quick and easy connection to the Vokera time clock. 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 tted (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-tted 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.

Fig. 17

Fig. 18

Hot water

outlet

Cold water inlet

stopcock/lling

valve

Gas

cock

C/H ow

valve

C/H return

valve

Safety

valve outlet

Page 19

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 specic 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 ushed in accordance with the following

instructions.

5.3 INITIAL FILLING OF THE SYSTEM

Ensure both ow 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

lling loop as shown in g. 5, slowly proceed to ll the system by rstly opening the inlet valve connected to the ow pipe, and then turning the lever on the ll 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 rst.

It may be necessary to go back and top-up the pressure until

the entire system has been lled. Inspect the system for water

tightness, rectifying any leaks.

5.3.1 MANUAL AIR RELEASE (g. 19)

When the boiler has been lled for the rst time or the system has been drained and relled, 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.

5.4 INITIAL FLUSHING OF THE SYSTEM

The whole of the heating system must be ushed both cold

and hot as detailed in 5.8. Open all radiator or heating valves

and the appliance ow & 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. Rell 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;

Fig. 19

• ensure the proper electrical checks have been carried out,

(see 7.8) particularly continuity, polarity and resistance to earth;

• ensure the 3 AMP fuse – supplied with the appliance – has been tted;

• ensure the system has been lled, vented and the pressure set to 1 BAR;

• ensure the ue system has been tted properly and in ac-

cordance 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 & faultnding).

5.7 CHECKING GAS PRESSURE AND COMBUS-

TION ANALYSIS

The appliance is factory set so should require no additional adjustment once installed. However to satisfy the require-

ments 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 accor-

dance with BS 7967 (UK) to ensure that correct combustion is occurring, see ow chart on page 32.

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 sufcient 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 ushed 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”.

5.9 SETTING THE FLOW OUTLET TEMPERA-

TURE

The ow outlet temperature can be adjusted between 40 °C -

80 °C for standard CH system by using the Heating thermostat

knob (see g.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 g.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

SECTION 5 - COMMISSIONING

Page 20

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 efcient 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 specic 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

sufcient. 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 qualied 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 specication. The cause of any noticeable deterioration should be identied and rectied without delay.

• Thoroughly inspect the appliance for signs of damage or deterioration especially the ue system and the electrical

(up to the maximum of 1.5 BAR total). N.B. The safety valve 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 gure registers on the pressure gauge (see g. 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 tted with a ow rate restrictor that limits the maximum ow rate that can be drawn through the appliance.

The restrictor eliminates the need to manually adjust the DHW

ow rate. However if it is felt necessary to further increase or decrease the available ow rate, spare restrictors are available

to Vokèra spare parts.

The spare ow rate restrictors can be tted to either increase or decrease the maximum ow rate.

5.11.2 FLOW-RATE RESTRICTOR

The boiler is supplied with the following ow restrictor.

Excel 25: 8 - litres ow restrictor Excel 29: 10 - litres ow 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 TIGHT-

NESS.

• 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 lling valve and how to top-

up 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 efcient 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

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 ue gases (see 7.5), and visually check the condition of the entire ue assembly.

• Compare the results with the appliance design specication. Any deterioration in performance must be identied and rectied 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 ame side of the burner is made of state-of-the-art material.

Being fragile:

- be particularly careful when handling, mounting or dismantling the bur ner and adjacent components (e.g. electrodes, insulation panelling etc.)

- avoid direct contact with any cleaning appliance (e.g. brushes, aspira tors, 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 nding section

will assist in determining which component is malfunctioning.

Page 21

Fig. 20

Fig. 21

Fig. 22

Fig. 23

Fig. 24

G H

Fig. 25

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.

6.4.1 AIR BOX FRONT COVER REMOVAL (g. 20)

Locate the 4 screws and remove air box front cover.

6.5 PUMP ASSEMBLY (g. 21)

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 exible 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.

6.6 SAFETY VALVE (g. 22)

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.

6.7 LOWER AUTOMATIC AIR RELEASE VALVE

(g. 21)

Carry out component removal procedure as described in 6.4. Remove the expansion pipe locking pin (B) from the pump as- sembly 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.

6.7.1 TOP AUTOMATIC AIR RELEASE VALVE (g. 23)

Carry out component removal procedure as described in 6.4. Remove the AAV locking pin (K) from the deaerator assembly and remove the AAV assembly (L). Replace in the reverse order.

6.8 WATER PRESSURE SWITCH (g. 24)

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 (g. 4 - pos. 17)

Carry out component removal procedure as described in 6.4.

Unclip and remove the air chamber front cover. Unclip the ow thermistor from the ow outlet pipe. Disconnect thermistor electrical plug. Replace in the reverse order.

6.10 RETURN THERMISTOR (g. 4 - pos. 20)

Carry out component removal procedure as described in 6.4. Unclip and remove the air chamber front cover. Unclip the return thermistor from the return inlet pipe. Disconnect thermistor

electrical plug. Replace in the reverse order.

6.11 PRINTED CIRCUIT BOARD (g. 25)

Carry out component removal procedure as described in 6.4. Pull the control fascia forward and lower it. Push the clips (O)

Page 22

6.14 FLUE FAN & MIXER (g. 28-29)

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.

6.15 BURNER (g. 28)

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.

Fig. 27

6.13 ELECTRODES (g. 27)

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. Re-

move the retaining screws (V) for electrode. Remove the spark ignition electrode (W). Remove the ame sensor electrod (Y).

6.12 GAS VALVE (g. 26)

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 (g. 26)

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.

Fig. 26

Fig. 28

which secure the PCB cover, remove cover, after carefully tak-

ing note of all wiring connections and jumper tag conguration. 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 conguration has been

respected. It will be necessary to check the functioning of the PCB is set for the correct boiler type/application.

Page 23

Fig. 29

Fig. 30

Fig. 32

Fig. 31

6.16 MAIN HEAT EXCHANGER (g. 29)

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 ow locking pin (M1), return locking pin (N1) on the heat exchanger. Locate and remove the 5-screws that secure the heat exchanger to the combustion chamber (O1).

Move the heat exchanger and disconnect it from the ue 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.

6.17 AUTOMATIC BY-PASS & DHW NON-RETURN VALVE (g. 30)

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.

6.18 EXPANSION VESSEL REMOVAL (g. 31)

Carry out component removal procedure as described in 6.4.

Disconnect the expansion vessel from the exible expansion pipe. Disconnect the exible expansion pipe from the vessel. Unscrew the nut that secures the vessel to the lower frame.

Locate and remove the screw (U1) that secure 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.

6.19 CONDENSE TRAP REMOVAL (g. 32)

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.

Page 24

6.20.3 VALVE ACTUATOR (g. 35)

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.

6.20.4 DHW THERMISTOR (g. 24)

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. Re- place in the reverse order.

6.20.5 DIVERTOR VALVE ASSEMBLY (g. 35)

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.

Fig. 35

6.20.2 DHW FLOW SWITCH (g. 34)

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 ow switch & DHW heat exchanger. Disconnect the wiring to the DHW ow switch. Slacken and unscrew the inlet connection. Unscrew the nut (E2). Lift the DHW ow switch housing from its seating. If necessary remove the locking pin (F2) from the DHW ow switch, taking care not to lose the oat contained within the housing. Replace in the reverse order ensuring that the housing is rmly

inserted onto its seating. Ensure all seals are in good condition, taking care to ensure they are replaced correctly.

Fig. 34

Fig. 33

6.20 FLUE COLLECTOR REMOVAL (g. 33)

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 ue gas analysis test point cover (Z1). Disconnect the ues

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

ue collector out off its location. Replace in the reverse order.

6.20.1 DHW FLOW RESTRICTOR (g. 34)

Carry out the component removal procedure as described in

6.4.

Disconnect the cold water inlet pipe at the DHW ow switch

(B2). Using a small screwdriver, gently ease the ow 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.

Page 25

7.3 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. 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), locate and press the CO

button (see g. 36 pos. SW1). Press the button the number of

times according the function requirement as par 7.3.1.

Set the ue gas analyser to read CO2, allow the burner to stabilise and insert the probe into the ue analysis test point (Y1-Z1 g. 33). The appliance will operate in CO2 mode for

approximately 15 minutes.

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 sufcient system water pressure (min. 0.5 bar)

to ensure the water pressure switch is activated. If there is in-

sufcient 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 briey to

the heating position, and then back to the DHW position. The

pump will run briey.

• SARA function: the SARA function permits the boiler (when

the set-point is within the SARA range) to automatically adjust (raise) the heating ow outlet temperature should the room

thermostat contacts remain closed for more that 20-minutes.

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 ow 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

ame 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 ow temperature sensor, consequently a high temperature at the ow sensor results in a lower fan

speed. As the water temperature increases, the temperature

sensors – located on the ow 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 ow 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 ow rate exceeding 2-litres per minute will activate the DHW ow switch whereupon the pump and fan will be activated via the ow 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 ame 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 satis-

ed, 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

specic appliance specication. Vokèra accepts no responsibility if the gas type is not correctly adjusted according to the

respective appliance specication as detailed on the appliance

data badge.

SECTION 7 - CHECKS, ADJUSTMENTS AND FAULT FINDING

Fig. 36

SW1

use the supplied

screwdriver to push the

CO botton (SW1)

Page 26

g. 37

7.3.2 GAS VALVE MAXIMUM SETTING

Set the CO2 button at maximum (see 7.3.1), once the maximum is obtained check that it corresponds with the appropriate CO

value (Maximum) for the respective appliance (see 2.11). If the CO

reading is correct, proceed to gas valve minimum setting (7.3.3). However, if the CO

reading is incorrect, the maximum gas

pressure must be adjusted as follows:

• using a 2.5mm Allen key, very slowly turn the maximum ad-

justment screw (see g. 37) – clockwise to decrease, counter

clockwise to increase – until the correct value is displayed on the CO

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 CO

value (Minimum) for the respective appliance (see 2.11). If the CO

reading is correct, proceed to completion (7.3.4).

However, if the CO

reading is incorrect, the minimum gas

pressure must be adjusted as follows:

• locate the minimum adjustment screw (g. 37), using a suit-

able screwdriver remove the protection plug

• using a 4mm Allen key, very slowly turn the minimum adjust-

ment screw (see g. 37) - clockwise to increase, counter

clockwise to decrease - until the correct value is displayed on the CO

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, ret the plug (g. 36 L2) and move the

mode selector throught

position. Remove the test probe

from the test point and ret 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

A combustion analysis check can easily be carried out on the appliance via the test points located on the top of the appliance (see 7.3).

• Operate the boiler in combustion analysis mode (see 7.3.1)

• Insert the ue gas analyser probe into the ue gas test point

(see g. 33) and compare the values with those shown in

section 2 (Nat. Gas) or section 10 (LPG). If different adjust the gas valve according to 7.3.1, 7.3.2, & 7.3.3.

The appliance will operate in CO2 mode for approximately 15minutes. 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.

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.

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 LED STATUS

combustion analysis mode press once = burner running at maximum heating yellow led blinking

gas valve maximun setting press twice = burner running at maximum DHW yellow led blinking + red led xed

gas valve minimum setting press three time = burner running at minimum yellow led blinking + green led xed

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

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 faultnding or component replacement,

ensure the fault is not attributable to any aspect of the installation.

7.6.1 INSTALLATION FAULTS Symptom Possible cause

No led/ignition Check wiring/check electrical supply

No hot water Check pipe-work No heating Check external controls

Fault Possible cause Red led xed Check gas supply, check ue

system, check polarity

7.7 ELECTRICAL CHECKS

Any electrical checks must be carried out by a suitably quali-

ed 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

Minimum

screw

Inlet gas pressure

connection

Compensation pipe

connection

Maximum

screw

Page 27

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 innity 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 faultnding 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

Before attempting any faultnding, 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 g.

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.

COMPONENT VALUE

Fan 230Vac Pump 230Vac Valve actuator 230Vac Ignition transformer 230Vac Gas valve 230Vac

Room thermostat connection 24Vdc

NTC thermistor (dry contact) 10Kohm NTC thermistor (wet contact) 10Kohm

FUNCTION VALUE

Standard Heating temperature range (min – max °C) 40 - 80 DHW temperature range (min – max °C) 37 - 60 75% maximum CH time 15 min Heating OFF hysterisis (°C) SP + 5 Heating ON hysterisis (°C) SP – 5 DHW OFF hysterisis (°C) SP + 5 DHW ON hysterisis (°C) SP + 4 Anti-cycle delay 3-min Pump over-run 30-sec Low output (min. output + %) Min+25 CO function max temp. (°C) 90 CO re-light temp. (°C) 78 CO function time 15-min Flow NTC max temp. (°C) 90 High limit thermostat (°C) 105 Flue NTC max temp. (°C) 125 Maximum differential (°C) 35

IGNITION CONTROL VALUE

Ignition attempts before L/O (lockout) 5

Re-ignition attempts after loss of ame signal 5

7.9 COMPONENT VALUES & CHARACTERISTICS

APPLIANCE STATUS LED AND FAULT CODES

When the boiler detects a temporary fault condition, the ap-

propriate led indication is shown. If/when the fault is nal, the

pump will perform a 60-second post circulation and rel LED will be illuminated. See table on pag. 4.

Page 28

8.1 EXTERNAL WIRING

The appliance comes supplied with a time clock to allow 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.

8.1.1 EXTERNAL WIRING LIMITATIONS

Low voltage and High voltage cables must be run separately. 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 (g. 39)

• programmable RF room thermostats (g. 39)

• low voltage (24Vdc) room thermostat (CN5 g. 40)

8.3 OTHER DEVICES

Contact the controls manufacturer and/or Vokèra technical

department should you require more specic 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.energyefciency.gov.uk).

8.4 VOKÈRA LOWER COVER MECHANICAL

CLOCK (g. 3)

The Vokèra lower cover mechanical clock kit (product code

20025081) is entirely suitable for the Excel 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 factory tted connector

plug and connect to the corresponding plug supplied with the mechanical clock wiring harness.

Ret the boiler casing.

Fit the cover kit to the boiler.

IMPORTANT

• The boiler must always be supplied with a permanent 230V

electrical supply.

• 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.

Fig. 39

Fig. 40

SECTION 8 - WIRING DIAGRAMS

Page 29

FUNCTIONAL DIAGRAM

Fig. 41

NOTE: L-N-E connection is advisable

AKL Main PCB

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

LED Led 1 (green) working status or temporary stop

Led 2 (yellow) CO2 function ON

Led 3 (red) boiler lock out

CN1-CN15 Connectors - CN5 Room thermostat (24 Vdc)

S.W. CO2 function button

F.S. (1) Flame sensor

F1 Fuse 3.15A T

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 ow 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)

Page 30

10.1 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

SECTION 10 - LPG INSTRUCTIONS

10.6 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. 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), locate and press the CO

button (see g. 36 pos. SW1). Press the button the number of

times according the function requirement as par 7.3.1.

Set the ue gas analyser to read CO2, allow the burner to stabilise and insert the probe into the ue analysis test point (Y1-Z1 g. 33). The appliance will operate in CO2 mode for

approximately 15 minutes.

10.6.1 CO2 FUNCTION SETTINGS

Locate the CO

button (see 7.3)

Select the main selector switch in position

CO2 FUNCTIONS ACTION ON THE BUTTON LED STATUS

combustion analysis mode press once = burner running at maximum heating yellow led blinking

gas valve maximun setting press twice = burner running at maximum DHW yellow led blinking + red led xed

gas valve minimum setting press three time = burner running at minimum yellow led blinking + green led xed

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

10.3 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 (CO

• To change the injector see 6.12.1

• To replace the ange on the silencer (only Excel 29) see 6.15

• To adjust CO2 values see 10.6

10.4 GAS SUPPLY

The gas supply must be connected to the appliance by a com-

petent LPG installer and must be of sufcient 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.

10.5 GAS SUPPLY INSTALLATION

The entire installation including the meter must be purged and checked for gas tightness.

10.2 TECHNICAL DATA

Gas Pressures Excel 25 Excel 29

Inlet pressure 37.0 mbar 37.0mbar

Heating maximum gas rate (kg/hr) 1.55 1.94

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 ange 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

Page 31

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 CO

value (Maximum) for the respective appliance. If the CO

reading is correct, proceed to gas valve minimum setting (10.7.2). However, if the CO

reading is incorrect, the maximum gas

pressure must be adjusted as follows:

• using a 2.5mm Allen key, very slowly turn the maximum ad-

justment screw (see g. 37) – clockwise to decrease, counter

clockwise to increase – until the correct value is displayed on the CO

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 CO

value (Minimum) for the respective appliance. If the CO

reading is correct, proceed to completion (10.7.3). However, if the CO

reading is incorrect, the minimum gas

pressure must be adjusted as follows:

•

locate the minimum adjustment screw (g. 37), using a suit-

able screwdriver remove the protection plug

• using a 4mm Allen key, very slowly turn the minimum adjust-

ment screw (see g. 37) - clockwise to increase, counter

clockwise to decrease - until the correct value is displayed on the CO

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, ret the plug (L2 j) and move the mode

selector to the

position. Remove the test probe from the

test point and ret 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

specic appliance specication. Vokèra accepts no responsibility if the gas type is not correctly adjusted according to the

respective appliance specication as detailed on the appliance

data badge.

Page 32

Page 33

Page 34

COMMISSIONING: CO AND COMBUSTION RATIO CHECK

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.

SET BOILER TO MAXIMUM RATE In accordance with section 7.3-

7.4, set boiler to operate at maximum rate (full load condition). Allow sufficient time for combustion to

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.

Is CO less than 350ppm AND CO/CO2 ratio

less than 0.004?

Check all seals around the appliance burner, internal flue seals, door and case seals. Rectify where necessary.

Is CO less than 350ppm AND CO/CO2 ratio

less than 0.004?

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.

YES

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.

SET BOILER TO MINIMUM RATE

In accordance with section 7.3-

7.4, set boiler to operate at minimum rate (to minimum load condition). Allow sufficient time for combustion to stabilise.

YES

Is CO less than 350ppm AND CO/CO2 ratio less than 0.004?

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.

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.

YES

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.

Page 35

Page 36

Cod. 20066496 - 07/13 - Ed. 3

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

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