VOKERA Vision S User Instructions

38

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.

Vision S

High efciency system boiler

Vision 20 S G.C. N° 41-094-79
Vision 25 S G.C. N° 41-094-80

36

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 Explanation of features 3

2.6 Automatic temperature control 3

How to... Page

3.1 How to top-up the system pressure 4

3.2 How to reset the appliance 4

3.3 How to shut down the system for short periods 4

3.4 How to shut down the system for long periods 4

3.5 How to care for the appliance 4

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

Installation and Servicing instructions

Design principles & operating sequence Page

1.1 Principle components 7

1.2 Mode of operation (at rest) 7

1.3 Mode of operation (heating) 7

1.4 Safety devices 7

Technical data Page

2.1 Central heating 8

2.2 Gas pressures 8

2.3 Expansion vessel 8

2.4 Dimensions 8

2.5 Clearances 8

2.6 Connections 8

2.7 Electrical 8

2.8 Flue details (concentric) 8

2.8A Flue details (twin pipes) 8

 2.9 Efciency 8

2.10 Emissions 8

2.11 Pump duty 9

General requirements (UK) Page

3.1 Related documents 10

3.2 Location of appliance 10

3.3 Gas supply 10

3.4 Flue system 10

3.5 Air supply 10

3.6 Water circulation 10

3.7 Electrical supply 11

3.8 Mounting on a combustible surface 11

3.9 Timber framed buildings 11

3.10 Inhibitors 11

General requirements (EIRE) Page
3A.1 Related documents 11
3A.2 Location of appliance 11
3A.3 Gas supply 11
3A.4 Flue system 11
3A.5 Air supply 12
3A.6 Water circulation 12
3A.7 Electrical supply 12
3A.8 Mounting on a combustible surface 12
3A.9 Timber framed buildings 12
3A.10 Inhibitors 12
3A.11 Declaration of conformity 12

Installation Page

4.1 Delivery 13

4.2 Contents 13

4.3 Unpacking 13

4.4 Preparation for mounting the appliance 13

 4.5 Fittingtheue 13

4.6 Connecting the gas & water 17

4.7 Electrical connections 17

Commissioning Page

5.1 Gas supply installation 18

5.2 The heating system 18

 5.3 Initialllingofthesystem 18
 5.4 Initialushingofthesystem 18

5.5 Pre-operation checks 18

5.6 Initial lighting 18

5.7 Checking gas pressure & combustion analysis 18

 5.8 Finalushingoftheheatingsystem 18

5.9 Setting the boiler operating temperature 18

5.10 Setting the system design pressure 18

5.11 Regulating the central heating system 19

5.12 Final checks 19

5.13 Instructing the user 19

Servicing Page

6.1 General 19

6.2 Routine annual servicing 19

6.3 Replacement of components 19

6.4 Component removal procedure 19

6.5 Pump assembly 20

6.6 Safety valve 20

6.7 Lower automatic air release valves 20

6.8 Water pressure switch 20

6.9 Flow thermistor 20

6.10 Return thermistor 20

6.11 Printed circuit board 20

6.12 Gas valve 21

6.13 Electrodes 21

6.14 Flue fan & mixer 21

6.15 Burner 21

6.16 Main heat exchanger 22

6.17 Automatic by-pass 22

6.18 Expansion vessel removal 22

6.19 Condense trap removal 22

6.20 Flue collector removal 23

 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 24

7.4 Combustion analysis test 24

7.5 Checking the expansion vessel 24

7.6 External faults 25

7.7 Electrical checks 25

 7.8 Faultnding 25

7.9 Component values & characteristics 25

7.10 Adjustments 26

Wiring diagrams Page

8.1 External wiring 29

8.2 Typical control applications 29

8.3 Other devices 29

L.P.G. instructions Page

9.1 Related documents 31

9.2 Technical data 31

9.3 Converting the appliance gas type 31

9.4 Gas supply 31

9.5 Gas supply installation 31

9.6 Checking the CO2 and adjusting the gas valve 31

Benchmark 35-36

Commissioning 37

1

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 Vision boiler supplies heated water to your radiators and
hot water to your hot water tank. 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.
Your Vision 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 Vision 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 Vision is equipped with a built-in frost protection system,
this enables the boiler to over-ride the time controls – even if
switched off – and operate the burner and/or pump, should
the temperature drop below 50C for the main. In particular the
burner will be in ON status until the main temperature reaches
35°C for CH 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 a large LCD display that indicates
the appliance operating status.

1. THINGS YOU SHOULD KNOW

Vision 20S - 25S

HEIGHT 715 mm

WIDTH 405 mm

DEPTH 248 mm

ABOVE 150 mm

BELOW 150 mm

LEFT SIDE 12 mm

RIGHT SIDE 12 mm

FRONT 600 mm

2

Fig. 1

PRESSURE GAUGE

Ensure the system pressure is set correctly (minimum 0.5-bar)

MODE SELECTOR SWITCH/HEATING TEMPERATURE SELECTOR

Mode selector switch:

Boiler at OFF/standby - Select this position when you want the boiler to
be switched off for short periods (days).

Heating & hot water - Select this position when you want the boiler to re­spond to a heating and hot water request from the time-clock programmer

Heating temperature selector: move the selector clockwise to increase
the heating outlet temperature, or counter-clockwise to reduce the tem­perature (range: 40°C-80°C for standard central heating).
The automatic temperature control function (SARA) is set within the blank
bullet points.

MODE SELECTOR SWITCH

HEATING TEMPERATURE SELECTOR

PRESSURE GAUGE

Boiler reset - Select this position if the boiler requires to be reset.

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

DISPLAY

SARA

function

3

DIGITAL DISPLAY

Symbol/Icon Description

Displayed when heating mode is active

Displayed when frost protection function is ac­tive

Displayed if an alarm or fault has been detected

Displayed when low system pressure has been
detected

Displayed when an external sensor is connected
to the boiler

Displayed if an ignition fault has been detected

2.1 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

NOTE

The appliance frost protection is active in all the boiler modes.
The temperature selector can be used to vary the temperature
of the water that circulates around your radiators.

The temperature range is adjustable between 40°C and 80°C.
Refer to the main appliance status table for fault indicator and

boiler status.

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, counter­clockwise to decrease – to the desired temperature setting. The
temperature can be set from a minimum of 40°C to a maximum

of 80°C (if standard CH mode is selected).

2.5 EXPLANATION OF FEATURES

Although the Vokèra Vision has been designed for simplicity of
use, it utilises the latest in boiler technology, enabling a host of

functions to be carried out simultaneously.

2.6 AUTOMATIC TEMPERATURE CONTROL

The automatic temperature control function (SARA), permits the
boiler (when the heating temperature selector is set within the
blank bullet points) to automatically adjust (raise) the heating.
The activation and the disable of the function is visualized on
the display.

2. GETTING STARTED



4

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.

3.3 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.

3. HOW TO...

Fig. 2

control

valve

temporary

connection

control

valve

supply pipe

double

check valve

ow/return

pipe

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.

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.

4. WHAT IF...

5

FAULT CODES

ALARM CODE CAUSE ALARM TYPE ACTION

_St

AUTOSTOP Final Call engineer

_CL

CALL FOR SERVICE Temporary then nal Call engineer

A01

Ignition failure, ame not sensed,

internal fault

Final Reset, check appliance operation

A02

Limit thermostat fault Final Reset, check appliance operation

A03

Fan tacho signal fault Final Reset check appliance operation, check fan

A04

Insufcient system water pressure Final

Check/rell system pressure, reset, check

appliance operation

A06

Jumper tag conguration Temporary Check jumper tag conguration

A07

Primary (ow) thermistor fault Temporary Check primary thermistor, check wiring

Primary (ow) thermistor over temperature

Temporary then nal Reset, check appliance operation

Temperature differential Final

Reset, check appliance operation, check
thermistors

A08

Return thermistor fault Temporary Check return thermistor, check wiring

Return thermistor over temperature Temporary then nal Reset, check appliance operation

Temperature differential inverted Final

Reset, check pump, ensure there is suf-

cient circulation around heating circuit/s

A09

Flue thermistor or ue thermistor

counter fault

Temporary

Check ue thermistor counter at power
on, check ue thermistor, check wiring

Flue thermistor over temperature Final Reset, check appliance operation

A11

False ame Temporary None

A77

Low temperature thermostat fault Temporary Check low temperature thermostat

Adj

Calibration Na None

ACO

Service operation Na None







Purge cycle mode active Na None

Flame ON Na None

Hours Stand-by Na None

- - OFF Na None

6

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 Vision comprises a range of high-efciency system boilers

with outputs of 20kW and 25kW. These appliances – by design
– incorporate electronic ignition, circulating pump, expansion
vessel, safety valve, pressure gauge and automatic by-pass.
The Vision 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 Vision can also be used with the

Vokèra twin ue system.
The Vision 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. 3

General layout

1 Drain valve
2 Three porte valve actuator
3 Safety valve
4 Pump
5 Bottom auto air vent (AAV)
6 Main heat exchanger
7 Flues thermistor (NTC)
8 Fan assembly with mixer
9 Silencer
10 Flue gas analysis test point
11 Flue outlet & air intake
12 Top AAV
13 De-aerator
14 Spark Electrode - Sensing Electrode
15 Ignition transformer
16 Flow thermistor (NTC) - High limit thermostat
17 Expansion vessel
18 Pressure switch
19 Return thermistor (NTC)
20 Gas valve
21 Condense trap

R Heating return connection

F Heating ow connection

G Gas connection

INTRODUCTION

INSTALLATION AND SERVICING INSTRUCTIONS

R F G

7

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. 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.

• anti-block function – the anti-block function enables the pump

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 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.

Fig. 4

Expansion

vessel

Safety

valve

Pump

Return

temperature

sensor

Main heat

exchanger

Bottom

AAV

Pressure

switch

Drain
valve

Flow temperature

sensor

Top AAV

Automatic

by-pass

CH

return

CH

ow

SECTION 1 - DESIGN PRINCIPLES AND OPERATING SEQUENCE

8

SECTION 2 - TECHNICAL DATA

2.1 Central Heating Vision 20S Vision 25S

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 3 bar

Minimum ow rate 350 l/h

2.2 Gas Pressures Vision 20S Vision 25S

Inlet pressure (G20) 20.0 mbar 20.0 mbar

Heating maximum gas rate (m3/hr) 2.12 2.64

Minimum gas rate (m3/hr) 0.53 0.63

Injector size (mm) 5.1 5.6

Silencer ange (ø mm) (tted) 31 -

2.3 Expansion Vessel Vision 20S Vision 25S

Capacity 8 litres

Maximum system volume 74 litres

Pre-charge pressure 1 bar

2.4 Dimensions Vision 20S Vision 25S

Height (mm) 715

Width (mm) 405

Depth (mm) 250

Dry weight (kg) 26 27

2.5 Clearances Vision 20S Vision 25S

Sides 12mm

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

Bottom 150mm

Front 600mm

2.6 Connections Vision 20S Vision 25S

Flow & return 22mm

Gas 22mm

Safety valve 15mm

Condense

21mm

2.7 Electrical Vision 20S Vision 25S

Power consumption (Watts) 96 107

Voltage (V/Hz) 230/50

Internal fuse 3.15A T (for PCB) - 3.15A F (for connections block)

External fuse 3A

2.8 Flue Details (concentric) Vision 20S Vision 25S

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

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

2.8A Flue Details (twin pipes) Vision 20S Vision 25S

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

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

2.9 Efciency Vision 20S Vision 25S

SEDBUK (%) 90.13 90.26

2.10 Emissions Vision 20S Vision 25S

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

9

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)

Fig. 5

2.11 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.

Fig. 6

1st speed

2nd speed

3rd speed

Flow rate (l/h)

Residual head (x 100 mbar)

0,0

1,0

2,0

3,0

4,0

5,0

6,0

0 100 200 300400 500600 700800 9001000

10

SECTION 3 - GENERAL REQUIREMENTS (UK)

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

3.1 RELATED DOCUMENTS

The installation of this boiler must be in accordance with the
relevant requirements of the Gas Safety (Installation & Use)
Regulations, the local building regulations, the current I.E.E.
wiring regulations, the bylaws of the local water undertaking,
the Building Standards (Scotland) Regulation and Building
Standards (Northern Ireland) Regulations.
It should be in accordance also with any relevant requirements
of the local authority and the relevant recommendations of the
following British Standard Codes of Practice.

3.2 LOCATION OF APPLIANCE

The appliance may be installed in any room or internal space,
although particular attention is drawn to the requirements
of the current I.E.E. wiring regulations, and in Scotland, the
electrical provisions of the Building Regulations, with respect
to the installation of the appliance in a room or internal space
containing a bath or shower.

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

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, should be

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.

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. 8).
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.

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.

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

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 g. 6). 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

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