Potterton Gold 24 HE Installation and maintenance instructions

Installation & Service Instructions Gold Combi HE
Range
This is a Wall Mounted Powered Flue Condensing Combination Boiler Gas Fired Central Heating Unit.
The boiler meets the requirements of Statutory Instrument “ The Boiler (Efficiency) Regulations 1993 No3083” and is
deemed to meet the requirements of Directive 92/42/EEC on the energy efficiency requirements for new hot water
boilers fired with liquid or gaseous fuels:-
Type test for purpose of Regulation 5 certified by:
Notified Body 0085.
Product/Production certified by:
Notified Body 0085.
For use in GB/IE only.
These instructions include the Benchmark Commissioning Checklist and should be left with the User for safe keeping.

Publication No. 5116282
2
Natural Gas
Potterton Gold 24 HE
G.C.No47 590 05
Potterton Gold 28 HE
G.C.No47 590 06
Potterton Gold 33 HE
G.C.No47 590 19
Building Regulations and the Benchmark
Commissioning Checklist
Building Regulations (England & Wales) require
notification of the installation of a heating appliance to
the relevant Local Authority Building Control
Department. From 1 April 2005 this can be achieved via
a Competent Persons Self Certification Scheme as an
option to notifying the Local Authority directly. Similar
arrangements will follow for Scotland and will apply in
Northern Ireland from 1 January 2006.
CORGI operate a Self Certification Scheme for gas
heating appliances.
These arrangements represent a change from the
situation whereby compliance with Building Regulations
was accepted as being demonstrated by completion of
the Benchmark Logbook (which was then left on site
with the customer).
With the introduction of Self Certification Schemes, the
Benchmark Logbook is being withdrawn. However, a
similar document in the form of a commissioning
checklist and service interval record is incorporated at
the back of these instructions.
Potterton is a member of the Benchmark initiative and
fully supports the aims of the programme. Its aim is to
improve the standards of installation and commissioning
of central heating systems in the UK and to encourage
the regular servicing of all central heating systems to
ensure safety and efficiency.
Building Regulations require that installations should
comply with manufacturer's instructions. It is therefore
important that the commissioning checklist is completed
by the installer. The relevant section of Building
Regulations only relates to dwellings. Therefore the
checklist only applies if the appliance is being installed
in a dwelling or some related structure.
The flowchart opposite gives guidance for installers on
the process necessary to ensure compliance with
Building Regulations.

3
INSTALLER NOTIFICATION GUIDELINES
Publication No. 5116282
Choose Building
Regulations Notification
Route
Contact your relevant Local
Authority Building Control
(LABC) who will arrange
an inspection or contact
a government approved
inspector
LABC will record the data
and will issue a
certificate of compliance
CORGI will record the data and
will send a certificate of
compliance to the property
You must ensure that the
notification number issued by
CORGI is writen onto the
Benchmark Checklist
Scheme Members only
Call CORGI on: 0870 88 88 777
or log onto:
www.corgi-notify.com
within 10 days
If you notify via CORGI Scheme,
CORGI will then notify the
relevant Local Authority
Building Control Scheme
on member's behalf
Complete the
Benchmark Checklist
Install and Commission this
appliance to manufacturer's
instructions
Competent Person's
Self Certification Scheme Building Control

LEGISLATION
4Publication No. 5116282
Codes of Practice - refer to the most recent
version
IMPORTANT - Installation, Commissioning, Service & Repair
This appliance must be installed in accordance with the manufacturer’s
instructions and the regulations in force. Read the instructions fully before
installing or using the appliance.
In GB, this must be carried out by a competent person as stated in the Gas
Safety (Installation & Use) Regulations.
Definition of competence: A person who works for a CORGI registered
company and holding current certificates in the relevant ACS modules, is
deemed competent.
In IE, this must be carried out by a competent person as stated in I.S. 813
“Domestic Gas Installations”.
Lifting - This product should be lifted and handled by two people. Stooping
should be avoided and protective equipment worn where necessary. Carrying
& lifting equipment should be used as required, e.g. when installing in a loft
space.
The addition of anything that may interfere with the normal operation of the
appliance without express written permission from the manufacturer or his
agent could invalidate the appliance warranty. In GB this could also infringe
the Gas Safety (Installation and Use) Regulations.
Warning - Check the information on the data plate is compatible with local
supply conditions.
All CORGI registered installers carry a CORGI identification card and have a
registration number. You can check your installer is registered by telephoning
0870 4012300 or writing to:-
1 Elmwood,
Chineham Business Park,
Crockford Lane,
Basingstoke. RG24 8WG
or check online at www.corgi-gas-safety.com
Potterton declare that no substances harmful to
health are contained in the appliance or used
during appliance manufacture.
The appliance is suitable only for installation in GB
and IE and should be installed in accordance with
the rules in force, and only used in a suitably
ventilated location.
In GB, the installation must be carried out by a CORGI
Registered Installer. It must be carried out in accordance
with the relevant requirements of the:
•Gas Safety (Installation & Use) Regulations.
•The appropriate Building Regulations either The
Building Regulations, The Building Regulations
(Scotland), Building Regulations (Northern Ireland).
•The Water Fittings Regulations or Water Byelaws in
Scotland.
•The Current I.E.E. Wiring Regulations.
Where no specific instructions are given, reference
should be made to the relevant British Standard Code of
Practice.
In IE, the installation must be carried out by a competent
Person and installed in accordance with the current
edition of I.S. 813 ‘Domestic Gas Installations’, the
current Building Regulations and reference should be
made to the current ETCI rules for electrical installation.
All systems must be thoroughly flushed and
treated with inhibitor (see section 6.2).
In GB the following Codes of Practice apply:
Standard Scope
BS 6891 Gas Installation.
BS 5546 Installation of hot water supplies for
domestic purposes.
BS 5449 Forced circulation hot water systems.
BS 6798 Installation of gas fired hot water boilers.
BS 5440 Part 1 Flues.
BS 5440 Part 2 Ventilation.
BS 7074 Expansion vessels and ancillary equipment
for sealed water systems.
BS 7593 Treatment of water in domestic hot water
central heating systems.
In IE the following Codes of Practice apply:
Standard Scope
I.S. 813 Domestic Gas Installations.
The following standards give valuable additional information;
BS 5546 Installation of hot water supplies for
domestic purposes.
BS 5449 Forced circulation hot water systems.
BS 7074 Expansion vessels and ancillary equipment
for sealed water systems.
BS 7593 Treatment of water in domestic hot water
central heating systems.

5
CONTENTS
1.0 Introduction 6
2.0 General Layout 7
3.0 Appliance Operation 8
4.0 Technical Data 9
5.0 Dimensions and Fixings 12
6.0 System Details 13
7.0 Site Requirements 16
8.0 Installation 22
9.0 Commissioning 28
10.0 Completion 31
11.0 Servicing 32
12.0 Changing Components 34
13.0 Combustion Check 43
14.0 Electrical 44
15.0 Short Parts List 45
16.0 Fault Finding 46
17.0 Notes 52
Benchmark Checklist 54
Section Page
Publication No. 5116282

1.0 INTRODUCTION
6
1.1 Description
1. The Potterton Gold Combi HE is a fully automatic
gas fired wall mounted condensing combination boiler.
It is room sealed and fan assisted, and will serve
central heating and mains fed domestic hot water.
2. The boiler is set to give a maximum output of :-
24 models - 24 kW DHW
25.9 kW CH (Condensing)
28 models - 28 kW DHW
25.9 kW CH (Condensing)
33 models - 33 kW DHW
30.3 kW CH (Condensing)
3. It is designed for use on Natural Gas (G20).
4. The boiler is suitable for use only on fully pumped
sealed heating systems. Priority is given to domestic
hot water.
5. The boiler is supplied with a filling loop and integral
timer.
6. The boiler data badge gives details of the model,
serial number and Gas Council number and is situated
on the control box. It is visible when the case front
panel is removed (Fig. 1).
7. The boiler is intended to be installed in residential /
commercial / light industrial E.M.C. environments on a
governed meter supply only.
8. The boiler must be installed with one of the purpose
designed flues such as the standard horizontal flue kit,
part no. 5111073.
9. All systems must be thoroughly flushed and
treated with inhibitor (see section 6.2).
1.2 Optional Extras
Various flue extensions, bends, vertical flue kits, etc.
are available as optional extras. These are detailed in
a separate publication.
NOTE: All illustrations show the Gold Combi 24 HE
unless otherwise stated.
Data Badge
Fig. 1
Control Box
Case Front Panel
Publication No. 5116282

7
2.0 GENERAL LAYOUT
2.1 Layout
1. Expansion Vessel
2. Automatic Air Vent
3. DHW Plate Heat Exchanger
4. Circulation Pump
5. Drain Off Point
6. Pressure Relief Valve
7. Integral Timer Position
8. Central Heating System Pressure Gauge
9. PCB
10. Control Box
11. 3-Way Valve Assembly
12. Condensate Trap
13. Flame Sensing Electrode
14. Spark Electrode
15. Primary Heat Exchanger
16. Fan Assembly
17. On/Off/Reset Selector Switch
18. Central Heating Temperature Control
19. Hot Water Temperature Control
20. Venturi
21. Air/Gas Collector
22. Combustion Box Cover & Burner
23. Igniter
24. Burner On Light
25. Central Heating Mode Light
26. Domestic Hot Water Mode Light
27. Display
1
17 18 19 87
2
1
0
4
3
bar
Reset
1
2
3
4
5
PM
7
8
9
10
11
12
1
2
3
4
5
AM
7
8
9
10
11
12
GRASSLIN
0
22
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
20
21
23
24
25 26
27
Publication No. 5116282

3.0 APPLIANCE OPERATION
8
3.1 Central Heating Mode (Fig. 2)
1. With a demand for heating, the pump circulates
water through the primary circuit.
2. Once main burner ignites the fan speed controls the
gas rate to maintain the heating temperature
measured by the temperature sensor.
3. When the flow temperature exceeds the setting
temperature, a 3 minute delay occurs before the
burner relights automatically (anti-cycling). The pump
continues to run during this period.
4. When the demand is satisfied the burner is
extinguished and the pump continues to run for a
period of 3 minutes (Pump Overrun).
3.2 Domestic Hot Water Mode (Fig. 3)
1. Priority is given to the domestic hot water supply. A
demand at a tap or shower will override any central
heating requirement.
2. The flow of water will operate the Hall Effect Sensor
which requests the 3 way valve to change position.
This will allow the pump to circulate the primary water
through the DHW plate heat exchanger.
3. The burner will light automatically and the
temperature of the domestic hot water is controlled by
the temperature sensor.
4. When the domestic hot water demand ceases the
burner will extinguish and the diverter valve will
remain in the domestic hot water mode, unless there
is a demand for central heating.
IMPORTANT: When the selector switch is in the ‘0’
(Off) position the electrical supply to the boiler is
isolated. The boiler will not operate and the integral
timer will require resetting once the selector switch
is set to either Position (i) or Position (ii).
3.3 Frost Protection Mode
1. The frost protection mode is integral to the
appliance and functions only with the selector switch
(see Section 2.1) in the domestic hot water and
central heating position. If the system temperature
falls below 5°C then the boiler will fire on its minimum
setting until a flow temperature of 30°C is reached.
Further protection can be incorporated by using a
system frost thermostat.
3.4 Pump Protection
1. With the selector switch (see Section 2.1) in either
the central heating or central heating and domestic hot
water position, the pump will automatically operate for
1 minute in every 24 hours to prevent sticking.
1
2
4
5 6
7
8
9
10
11
1213141516
17
18
19
21
22
24
25
26
3
1 Primary Heat Exchanger
2 Burner
3 Ignition Electrode
4 Flame Sensing Electrode
5 Gas Valve
6Pump
7 Automatic Air Vent
8 Plate Heat Exchanger
9 Flow Sensor with Filter & Regulator
10 Pressure Relief Valve
11 Boiler Drain Point
12 Heating Return
13 Cold Water Inlet On/Off Valve and Filter
14 Gas Inlet
15 Domestic Hot Water Outlet
16 Heating Flow
17 Pressure Gauge
18 Water Pressure Sensor
19 Automatic By-Pass
20 Fan
21 Diverter Valve Assembly
22 Diverter Valve Motor
23 Domestic Hot Water Flow Temperature Sensor
24 Safety Thermostat
25 Central Heating Temperature Sensor
26 Expansion Vessel
Key
Central Heating Circuit
Domestic Hot Water Circuit
Fig. 3
1
2
4
5 6
7
8
9
10
11
1213141516
17
18
19
21
22
24
25
26
3
Fig. 2
23
23
20
20
Publication No. 5116282

9
4.0 TECHNICAL DATA
4.1 Gold Combi 24 HE
Flue Terminal Diameter 100mm
Dimensions Projection 125mm
Outercase Dimensions
Casing Height - 780mm
Overall Height Inc Flue
Elbow - 965mm
Casing Width - 450mm
Casing Depth - 345mm
Weights kg
Packaged Boiler Carton 56.5
Installation Lift Weight 45
Central Heating Primary Circuit
Pressures
bar
Safety Discharge 3
Max Operating 2.5
Min Operating 0.5
Recommended Operating Range 1-2
DHW Circuit bar
Pressures
Max Operating 8
Min Operating 0.15
Flow Rates l/min
DHW Flow Rate
@ 30o C Rise 11.43
DHW Flow Rate
@ 35o C Rise 9.8
Min Working
DHW Flow Rate 2
Pump
Available Head See graph below
Expansion Vessel - (For Central Heating
only. Integral with appliance)
bar
Min Pre-charge Pressure 0.5
litre
Max Capacity of
CH System 125
Primary Water Content
of Boiler (unpressurised) 2.5
Connections copper tails
Gas Supply - 22mm
Central Heating Flow - 22mm
Central Heating Return - 22mm
Cold Water Mains Inlet - 15mm
DHW Flow - 15mm
Pressure Relief Discharge - 15mm
Temperatures
C.H. Flow Temp (adjustable)
25°C to 80°C max (± 5°C)
D.H.W. Flow Temp (adjustable)
35°C to 60°C max (± 5°C)
dependent upon flow rate
NOxClass 5
0
200 400 600 800 1000 1200
0.5
1
1.5
2
2.5
3
3.5
4
Metre (wg)
Flow Rate (l/h)
Pump - Available Head
0
5
5.5
4.5
Clearances
Above Casing 200 mm Min
Below Casing 200 mm Min
Front 450 mm Min (For Servicing)
Front 5 mm Min (In Operation)
L.H. Side 5 mm Min
R.H. Side 5 mm Min (In Operation)
Heat Input CH (Net)
Max Min
kW 24.7 7
Heat Output CH (Non-Condensing)
Max Min
kW 24 6.8
Electrical Supply 230V~ 50Hz
(Appliance must be connected to an
earthed supply)
Power Consumption 155W
Electrical Protection IPX0D
Internal Fuse Rating
F2L
Appliance Category CAT I 2H
Inlet Pressure (Natural Gas - G20)
mbar 20
Injector (Natural Gas - G20)
7.5mm
Appliance Type C13 C33
Heat Output CH (Condensing)
Max Min
kW 25.9 7.4
Heat Input DHW (Net)
Max
kW 24.7
Heat Output DHW
Max
kW 24
Max Gas Rate (Natural Gas - G20)
(After 10 mins)
m3/h 2.61
This value is used in the UK Government’s Standard Assessment
Procedure (SAP) for energy rating of dwellings. The test data from
which it has been calculated have been certified by 0085.
SEDBUK Declaration For Gold 24 HE
The seasonal efficiency (SEDBUK) is 90.1%
Band A
Condensate Drain
To accept 21.5mm (3/4in) plastic waste pipe
Heat Input CH (Gross)
Max Min
kW 27.4 7.8
Heat Input DHW (Gross)
Max
kW 27.4
Publication No. 5116282
External Fuse Rating 3A

4.0 TECHNICAL DATA
10 Publication No. 5116282
4.2 Gold Combi 28 HE
Flue Terminal Diameter 100mm
Dimensions Projection 125mm
Outercase Dimensions
Casing Height - 780mm
Overall Height Inc Flue
Elbow - 965mm
Casing Width - 450mm
Casing Depth - 345mm
Weights kg
Packaged Boiler Carton 56.5
Installation Lift Weight 45
Central Heating Primary Circuit
Pressures
bar
Safety Discharge 3
Max Operating 2.5
Min Operating 0.5
Recommended Operating Range 1-2
DHW Circuit bar
Pressures
Max Operating 8
Min Operating 0.15
Flow Rates l/min
DHW Flow Rate
@ 30o C Rise 13.3
DHW Flow Rate
@ 35o C Rise 11.5
Min Working
DHW Flow Rate 2
Pump
Available Head See graph below
Expansion Vessel - (For Central Heating
only. Integral with appliance)
bar
Min Pre-charge Pressure 0.5
litre
Max Capacity of
CH System 125
Primary Water Content
of Boiler (unpressurised) 2.5
Connections copper tails
Gas Supply - 22mm
Central Heating Flow - 22mm
Central Heating Return - 22mm
Cold Water Mains Inlet - 15mm
DHW Flow - 15mm
Pressure Relief Discharge - 15mm
Temperatures
C.H. Flow Temp (adjustable)
25°C to 80°C max (± 5°C)
D.H.W. Flow Temp (adjustable)
35°C to 60°C max (± 5°C)
dependent upon flow rate
NOxClass 5
0
200 400 600 800 1000 1200
0.5
1
1.5
2
2.5
3
3.5
4
Metre (wg)
Flow Rate (l/h)
Pump - Available Head
0
5
5.5
4.5
Clearances
Above Casing 200 mm Min
Below Casing 200 mm Min
Front 450 mm Min (For Servicing)
Front 5 mm Min (In Operation)
L.H. Side 5 mm Min
R.H. Side 5 mm Min (In Operation)
Heat Input CH (Net)
Max Min
kW 24.7 9
Heat Output CH (Non-Condensing)
Max Min
kW 24 8.7
Electrical Supply 230V~ 50Hz
(Appliance must be connected to an
earthed supply)
Power Consumption 155W
Electrical Protection IPX0D
Internal Fuse Rating
F2L
Appliance Category CAT I 2H
Inlet Pressure (Natural Gas - G20)
mbar 20
Injector (Natural Gas - G20)
7.5mm
Appliance Type C13 C33
Heat Output CH (Condensing)
Max Min
kW 25.9 9.5
Heat Input DHW (Net)
Max
kW 28.9
Heat Output DHW
Max
kW 28
Max Gas Rate (Natural Gas - G20)
(After 10 mins)
m3/h 3.1
This value is used in the UK Government’s Standard Assessment
Procedure (SAP) for energy rating of dwellings. The test data from
which it has been calculated have been certified by 0085.
SEDBUK Declaration For Gold 24 HE
The seasonal efficiency (SEDBUK) is 90.1%
Band A
Condensate Drain
To accept 21.5mm (3/4in) plastic waste pipe
Heat Input CH (Gross)
Max Min
kW 27.4 10
Heat Input DHW (Gross)
Max
kW 32.1
External Fuse Rating 3A

11
4.0 TECHNICAL DATA
Publication No. 5116282
4.3 Gold Combi 33 HE
Flue Terminal Diameter 100mm
Dimensions Projection 125mm
Outercase Dimensions
Casing Height - 780mm
Overall Height Inc Flue
Elbow - 965mm
Casing Width - 450mm
Casing Depth - 345mm
Weights kg
Packaged Boiler Carton 57.5
Installation Lift Weight 46
Central Heating Primary Circuit
Pressures
bar
Safety Discharge 3
Max Operating 2.5
Min Operating 0.5
Recommended Operating Range 1-2
DHW Circuit bar
Pressures
Max Operating 8
Min Operating 0.15
Flow Rates l/min
DHW Flow Rate
@ 30o C Rise 15.7
DHW Flow Rate
@ 35o C Rise 13.5
Min Working
DHW Flow Rate 2
Pump
Available Head See graph below
Expansion Vessel - (For Central Heating
only. Integral with appliance)
bar
Min Pre-charge Pressure 0.5
litre
Max Capacity of
CH System 155
Primary Water Content
of Boiler (unpressurised) 2.8
Connections copper tails
Gas Supply - 22mm
Central Heating Flow - 22mm
Central Heating Return - 22mm
Cold Water Mains Inlet - 15mm
DHW Flow - 15mm
Pressure Relief Discharge - 15mm
Temperatures
C.H. Flow Temp (adjustable)
25°C to 80°C max (± 5°C)
D.H.W. Flow Temp (adjustable)
35°C to 60°C max (± 5°C)
dependent upon flow rate
NOxClass 5
0
200 400 600 800 1000 1200
0.5
1
1.5
2
2.5
3
3.5
4
Metre (wg)
Flow Rate (l/h)
Pump - Available Head
0
5
5.5
4.5
Clearances
Above Casing 200 mm Min
Below Casing 200 mm Min
Front 450 mm Min (For Servicing)
Front 5 mm Min (In Operation)
L.H. Side 5 mm Min
R.H. Side 5 mm Min (In Operation)
Heat Input CH (Net)
Max Min
kW 28.9 9.7
Heat Output CH (Non-Condensing)
Max Min
kW 28 9.4
Electrical Supply 230V~ 50Hz
(Appliance must be connected to an
earthed supply)
Power Consumption 160W
Electrical Protection IPX0D
Internal Fuse Rating
F2L
Appliance Category CAT I 2H
Inlet Pressure (Natural Gas - G20)
mbar 20
Injector (Natural Gas - G20)
12mm
Appliance Type C13 C33
Heat Output CH (Condensing)
Max Min
kW 30.3 10.2
Heat Input DHW (Net)
Max
kW 34
Heat Output DHW
Max
kW 33
Max Gas Rate (Natural Gas - G20)
(After 10 mins)
m3/h 3.6
This value is used in the UK Government’s Standard Assessment
Procedure (SAP) for energy rating of dwellings. The test data from
which it has been calculated have been certified by 0085.
SEDBUK Declaration For Gold 24 HE
The seasonal efficiency (SEDBUK) is 90.1%
Band A
Condensate Drain
To accept 21.5mm (3/4in) plastic waste pipe
Heat Input CH (Gross)
Max Min
kW 32.1 10.8
Heat Input DHW (Gross)
Max
kW 37.7
External Fuse Rating 3A

5.0 DIMENSIONS AND FIXINGS
12
Dimensions
A780mm
B345mm
C450mm
D116mm ØMin.
E185mm
F145mm
G131mm
H 180mm
Domestic Hot
Water Outlet
(15mm)
Cold Water
Inlet
(15mm)
Heating
Return
(22mm)
Heating
Flow
(22mm)
Pressure Relief
Valve
(15mm)
Gas
Inlet
(22mm)
65 mm 65 mm 65 mm 65 mm 65 mm
32.5 mm
Condensate
Drain
Tap Rail
360°Orientation
Tube Ø100mm
D
C
B
A
E
G
F
3o
H
Publication No. 5116282

13
6.0 SYSTEM DETAILS
6.1 Information
1. The Potterton Gold HE Condensing Combination Boiler
is a ‘Water Byelaws Scheme - Approved Product’.
To comply with the Water Byelaws your attention is drawn
to the following installation requirements and notes (IRN).
a) IRN 001 - See text of entry for installation
requirements and notes.
b) IRN 302 - Byelaw 14.
2. Reference to the WRc publications, ‘Water fittings and
materials directory’and ‘Water supply byelaws guide’give
full details of byelaws and the IRNs.
6.2 Central Heating Circuit
1. The appliance is suitable for fully pumped SEALED
SYSTEMS ONLY.
Treatment of Water Circulating Systems
•All recirculatory water systems will be subject to
corrosion unless an appropriate water treatment is
applied. This means that the efficiency of the system will
deteriorate as corrosion sludge accumulates within the
system, risking damage to pump and valves, boiler noise
and circulation problems.
•When upgrading existing systems that exhibit evidence
of sludging, it is advisable to clean the system prior to
treatment in order to remove any sludge and reduce the
likelihood of these deposits damaging new components.
•When fitting new systems flux will be evident within the
system, which can lead to damage of system components.
•All systems must be thoroughly drained and flushed out.
The recommended flushing and cleansing agents are
Betz-Dearborn Sentinel X300 or X400 and Fernox
Superfloc Universal Cleanser which should be used
following the flushing agent manufacturer’s instructions.
•System additives - corrosion inhibitors and flushing
agents/descalers should comply to BS7593 requirements.
The only system additives recommended are Betz-
Dearborn Sentinel X100 and Fernox-Copal which should
be used following the inhibitor manufacturer’s instructions.
Failure to flush and add inhibitor to the system will
invalidate the appliance warranty.
•It is important to check the inhibitor concentration after
installation, system modification and at every service in
accordance with the manufacturer’s instructions. (Test kits
are available from inhibitor stockists.)
•For information or advice regarding any of the above
contact Technical Enquiries.
6.3 Bypass
1. The boiler is fitted with an automatic integral bypass.
6.4 System Control
1. A 24 hour electro - mechanical timer is supplied
fitted to the boiler.
2. Further external controls (e.g. room thermostat)
should be fitted to optimise the economical operation
of the boiler.
Publication No. 5116282

6.0 SYSTEM DETAILS
14
6.5 System Filling and Pressurising
1. A filling point connection on the central heating
return pipework must be provided to facilitate initial
filling and pressurising and also any subsequent water
loss replacement/refilling.
2. There are connection points on the mains cold water
inlet and central heating return isolating taps (Fig. 5) to
which the filling loop kit supplied can be assembled. If
the boiler is to be installed in an inaccessible location
(e.g. loft space) the filling point should remain
accessible. Also the fitting of an additional pressure
gauge in a visible position is recommended. The kit
supplied can still be used for this elsewhere on the
system, or if necessary a more suitable propriety kit
can be fitted.
3. The filling method adopted must be in accordance
with all relevant water supply regulations and use
approved equipment.
4. Your attention is drawn to:
for GB: Guidance G24.2 and recommendation R24.2 of
the Water Regulations Guide.
for IE: the current edition of I.S. 813 “Domestic Gas
Installations”.
5. The sealed primary circuits may be filled or
replenished by means of a temporary connection
between the circuit and a supply pipe, provided a
‘Listed’double check valve or some other no less
effective backflow prevention device is permanently
connected at the inlet to the circuit and the temporary
connection is removed after use.
6.6 Expansion Vessel (Central Heating only)
1. The appliance expansion vessel is pre-charged to
0.5 bar. Therefore, the minimum cold fill pressure is 0.5
bar. The vessel is suitable for correct operation for
system capacities up to 125 litres. For greater system
capacities an additional expansion vessel must be
fitted. For GB refer to BS 7074 Pt 1. For IE, the current
edition of I.S. 813 “Domestic Gas Installations”.
6.7 Pressure Relief Valve (Fig. 6)
1. The pressure relief valve is set at 3 bar, therefore all
pipework, fittings, etc. should be suitable for pressures
in excess of 3 bar and temperature in excess of 100°C.
2. The pressure relief discharge pipe should be not
less than 15mm dia, run continuously downward, and
discharge outside the building, preferably over a drain.
It should be routed in such a manner that no hazard
occurs to occupants or causes damage to wiring or
electrical components. The end of the pipe should
terminate facing down and towards the wall.
3. The discharge must not be above a window,
entrance or other public access. Consideration must be
given to the possibility that boiling water/steam could
discharge from the pipe.
Fig. 4
Fig. 6
Fig. 5
Stop
Valve
Double
Check
Valve
DHW
Mains
Inlet
CH
Return
Temporary
Hose
Pressure Relief Valve
Discharge Pipe
Filling Loop
Stop
Valve
Publication No. 5116282

15
6.0 SYSTEM DETAILS
6.8 Domestic Hot Water Circuit (Fig. 7)
1. All DHW circuits, connections, fittings, etc. should
be fully in accordance with relevant standards and
water supply regulations.
2. Your attention is drawn to:
for GB: Guidance G17 to G24 and recommendation
R17 to R24 of the Water Regulations Guide.
for IE: the current edition of I.S. 813 “Domestic Gas
Installations”.
3. A single check valve must be fitted as shown in
Fig. 7 to prevent backflow to the supply pipe and to
ensure the efficient operation of the expansion vessel
which is required to accommodate the thermal
expansion of the water.
4. When the domestic water system includes any
device which prevents water expanding back towards
the supply (check valve, loose jumpered stopcock,
water meter, water treatment device) then an
expansion vessel must be fitted (eg. Zilmet 160ml,
R1/215bar).
5. If the hot water expansion is not provided for, then
high pressures can develop which may result in
damage to fittings and devices on the system.
6. The boiler’s maximum working mains pressure is 8
bar, therefore all pipework, connections, fittings, etc.
should be suitable for pressures in excess of 8 bar. A
pressure reducing valve must be fitted for pressures
in excess of 8 bar. The manufacturer of any outlet
fittings, such as a shower valve, may require a lower
maximum pressure. The pressure reduction must
take account of all fittings connected to the DHW
system.
6.9 Showers
1. If a shower control is supplied from the appliance it
should be of the thermostatic or pressure balanced
type. Thermostatic type shower valves provide the
best comfort and guard against water at too high a
temperature. Existing controls may not be suitable -
refer to the shower valve manufacturer.
6.10 Hard Water Areas
1. If the area of the installation is recognised as a
HARD WATER AREA then a suitable device should
be fitted to treat the mains water supply to the boiler.
Contact your Water Distribution Company for advice
on suitable devices.
Boiler
Other Tap
Outlets
Expansion
Vessel
To Hot
Taps
Check
Valve
Pressure
Reducer Valve
Stop Tap
Fig. 7
Publication No. 5116282

7.0 SITE REQUIREMENTS
16
7.1 Location
1. The boiler may be fitted to any suitable wall with
the flue passing through an outside wall or roof and
discharging to atmosphere in a position permitting
satisfactory removal of combustion products and
providing an adequate air supply. The boiler should
be fitted within the building unless otherwise
protected by a suitable enclosure i.e. garage or
outhouse. (The boiler may be fitted inside a
cupboard-see Section 7.3).
2. If the boiler is sited in an unheated enclosure then
it is recommended to leave the ON/OFF Selector
Switch in the domestic hot water and central heating
position to give frost protection.
3. If the boiler is fitted in a room containing a bath or
shower reference must be made to the relevant
requirements.
In GB this is the current I.E.E. Wiring Regulations and
Building Regulations.
In IE reference should be made to the current edition
of I.S. 813 “Domestic Gas Installations”and the
current ETCI rules.
4. If the boiler is to be fitted into a building of timber
frame construction then reference must be made to
the current edition of Institute of Gas Engineers
Publication IGE/UP/7 (Gas Installations in Timber
Framed Housing).
7.2 Clearances (Figs. 8 & 9)
1. A flat vertical area is required for the installation of
the boiler.
2. These dimensions include the necessary
clearances around the boiler for case removal,
spanner access and air movement. Additional
clearances may be required for the passage of pipes
around local obstructions such as joists running
parallel to the front face of the boiler.
200mm Min
780mm
450mm
200mm Min
5mm Min
5mm Min
450mm Min
For Servicing
Purposes
Fig. 8
Fig. 9
In Operation
5mm Min
3°
Publication No. 5116282

17
7.0 SITE REQUIREMENTS
7.3 Ventilation of Compartments
1. Where the appliance is installed in a cupboard or
compartment, no air vents are required.
2. BS 5440: Part 2 refers to room sealed appliances
installed in compartments. The appliance will run
sufficiently cool without ventilation.
7.4 Gas Supply
1. The gas installation should be in accordance with
the relevant standards. In GB this is BS 6891. In IE
this is the current edition of I.S. 813 “Domestic Gas
Installations”.
2. The connection to the appliance is a 22mm
copper tail located at the rear of the gas service
cock (Fig. 10).
3. Ensure that the pipework from the meter to the
appliance is of adequate size. Do not use pipes of a
smaller diameter than the boiler gas connection
(22mm).
7.5 Electrical Supply
1. External wiring must be correctly earthed,
polarised and in accordance with relevant
regulations/rules. In GB this is the current I.E.E.
Wiring Regulations. In IE reference should be made
to the current edition of ETCI rules.
2. The mains supply is 230V ~ 50Hzfused at 3A.
NOTE: The method of connection to the
electricity supply must facilitate complete
electrical isolation of the appliance.
Connection may be via a fused double-pole
isolator with a contact separation of at least 3mm
in all poles and servicing the boiler and system
controls only.
Fig. 10
Gas Service Cock
Publication No. 5116282

7.0 SITE REQUIREMENTS
18
7.6 Condensate Drain
FAILURE TO INSTALL THE CONDENSATE DISCHARGE
PIPEWORK CORRECTLY WILL AFFECT THE
RELIABLE OPERATION OF THE BOILER
The condensate discharge pipe MUST NOT RISE at any
point along its length. There MUST be a fall of AT
LEAST 2.5° (50mm per metre) along the entire run.
1. The condensate outlet will accept 21.5mm (3/4in) plastic
overflow pipe which should generally discharge internally
into the household drainage system. If this is not
possible, discharge into an outside drain is acceptable.
2. Ensure the discharge of condensate complies with any
national or local regulations in force.
BS 6798:2000 & Part H1 of the Building Regulations
give further guidance.
3. The discharge pipe should be run in a proprietary drain
pipe material e.g. PVC, PVC-U, ABS, PVC-C or PP.
4. Metal pipework is NOT suitable for use in condensate
discharge systems.
5. The pipe should be a minimum of 21.5mm diameter
and must be supported using suitably spaced clips to
prevent sagging.
6. Any pipe fitted externally must not exceed 3
metres.
7. Any condensate discharge pipework external to
the building (or in an unheated part of it e.g. garage)
must be insulated to protect against frost. It is also
recommended that the pipe diameter is increased to
32mm.
8. If the boiler is fitted in an unheated location the entire
condensate discharge pipe should be treated as an
external run.
9. In all cases discharge pipe must be installed to aid
disposal of the condensate. To reduce the risk of
condensate being trapped, as few bends and fittings as
possible should be used.
10. When discharging condensate into a soil stack or
waste pipe the effects of existing plumbing must be
considered. If soil pipes or waste pipes are subjected to
internal pressure fluctuations when WC's are flushed or
sinks emptied then back-pressure may force water out of
the boiler trap and cause appliance lockout.
Examples are shown of the following methods of
termination:-
i) to an internal soil & vent pipe
ii) via an internal discharge branch (e.g. sink waste)
iii) to a drain or gully
iv) to a purpose made soakaway
Boiler
2.5°Minimum fall
Termination to an internal soil
and vent pipe
450mm min
Boiler
2.5°Minimum fall
External termination via internal
discharge branch
e.g sink waste - downstream
Sink
Pipe must terminate
above water level but
below surrounding
surface
Boiler Pipe must terminate
above water level but
below surrounding
surface
2.5°Minimum fall
Termination to a drain or gully
Boiler
500mm min
2.5°Minimum fall
Termination to a purpose made
soak-away
Holes in the soak-away
must face away from the
building
50mm per metre of pipe run
50mm per metre of pipe run
50mm per metre of pipe run
50mm per metre of pipe run
Publication No. 5116282

19
7.0 SITE REQUIREMENTS
7.7 Flue
NOTE: Due to the nature of the boiler a plume of
water vapour will be discharged from the flue. This
should be taken into account when siting the flue
terminal.
1. The following guidelines indicate the general
requirements for siting balanced flue terminals. For
GB recommendations are given in BS 5440 Pt 1. For
IE recommendations are given in the current edition
of I.S. 813 “Domestic Gas Installations”.
2. If the terminal discharges onto a pathway or
passageway, check that combustion products will not
cause a nuisance and that the terminal will not
obstruct the passageway.
3. If a terminal is less than 2 metres above a balcony,
above ground or above a flat roof to which people
have access, then a suitable terminal guard must be
provided.
Terminal Position with Minimum Distance (Fig. 11) (mm)
A* Directly below an openable window, air vent or any other
ventilation opening. 300
B Below gutter, drain/soil pipe. 25
C Below eaves. 25
D Below a balcony/car port roof. 25
E From vertical drain pipes and soil pipes. 25
F From internal or external corners. 25
G Above adjacent ground or balcony level. 300
H From a surface facing a terminal. 600
I Facing a terminals. 1200
J From opening (door/window) in carport into dwelling. 1200
K Vertically from a terminal on the same wall. 1500
L Horizontally from a terminal on the same wall. 300
M* Above an opening, air brick, opening window etc. 300
N* Horizontally to an opening, air brick, opening window etc. 300
L
G
G
E
J
D
K
G
AAD
F
H,I
B,C
F
Likely flue positions requiring
a flue terminal guard
M
N
Fig. 11
300 min
Terminal
Assembly
Top View Rear Flue
Property Boundary Line
* In addition, the terminal should be no nearer than 150mm to an
opening in the building fabric formed for the purpose of
accommodating a built-in element such as a window frame. See
BS 5440 Pt. 1.
Fig. 12
Publication No. 5116282

7.0 SITE REQUIREMENTS
20
7.8 Flue Dimensions
The standard horizontal flue kit allows for flue lengths
between 100mm and 685mm from elbow to terminal
(Fig. 13).
The maximum permissible equivalent flue length
is: 10 metres
7.9 Flue Trim
1. The rubber flue trim supplied may be fitted to either
the outside wall or on the inner wall of installation.
7.10 Terminal Guard (Fig. 14)
1. When codes of practice dictate the use of terminal
guards, they can be obtained from most Plumbers’
and Builders’Merchants.
2. There must be a clearance of at least 50mm
between any part of the terminal and the guard.
3. When ordering a terminal guard, quote the
appliance name and model number.
4. The flue terminal guard should be positioned
centrally over the terminal and fixed as illustrated.
Fig. 13
Fig. 14
100mm 685mm
Publication No. 5116282