Benchmark GB10 User guide

DESIGN, INSTALLATION
AND SERVICING INSTRUCTIONS
THE GAS SAFETY (INSTALLATION AND USE)
REGULATIONS
In your own interest and that of safety, it is
law that all gas appliances are installed by
competent persons and in accordance with the
above regulations.
Gledhill High Efficiency
Condensing Boiler
Models: GB10 GB15 GB20 GB25 GB30

ISSUE 5: 06-08

Page 2
TM
benchmark
The code of practice for the installation,
commissioning & servicing of central heating systems
GENERAL
This high efficiency wall mounted condensing boiler is designed to provide
central heating from a fully pumped open vented or sealed water system when
coupled to a thermal store or an indirect cylinder.
The central heating water temperature can be adjusted by the installer to suit
special applications.
Once the controls are set, the boiler operates automatically and the boiler
controller automatically activates the frost protection program to prevent the
boiler from freezing.
This boiler is for use with Natural Gas (G20) only at 20mbar inlet pressure and
is for use in GB &IE only.
Appliance category: I2H
Appliance types: C13, C73, C33
These instructions cover the following boiler models and only apply to the
appliances sold and installed in Great Britain (GB) and Ireland (IE).
These appliances have been certified for safety and therefore it is important
these instructions must be followed. Both the appliance and the installation
specifications must not be modified unless recommended and approved by
Gledhill Limited in writing. Any alteration not approved by Gledhill Ltd.,could
invalidate the certification, boiler warranty and may also infringe the current
issue of statutory requirements.
Gledhill wall mounted condensing boiler models
Model Reference SEDBUK Rating Gas Council Number
GB10 90.0 % - Band ‘A’ 41-317--01
GB15 90.3 % - Band ‘A’ 41-317-02
GB20 90.4 % - Band ‘A’ 41-317-03
GB25 90.4 % - Band ‘A’ 41-317-04
GB30 90.3 % - Band ‘A’ 41-317-05
The Gas Safety (Installation and use) Regulations 1998
“In your own interest, and that of safety, it is law that all gas appliances are
installed by competent persons, in accordance with the above regulations.
Failure to install appliances correctly could lead to prosecution.”
IMPORTANT NOTES
ISSUE 5: 06-08
Control of Substances Harmful to Health
When working with insulation materials, avoid
inhalation as it may be harmful to health. Avoid
contact with skin,eyes,nose and throat.Use disposable
protection. Dampen the material and ensure that the
area is well ventilated.
INSTRUCTIONS
The instructions are an integral part of the appliance
and therefore read these Instructions before installing
or lighting the appliance. Also to comply with the
current issue of the Gas Safety (Installation and Use),
these instructions must be handed to the user on
completion of the installation,
It is a requirement of the Building Regulations that
an approved commissioning checklist is completed
by the installer. The approved Benchmark checklist is
included on page 35.
Gledhill Water Storage Limited
Sycamore Estate
Squires Gate
BLACKPOOL
Lancs
FY4 3RL

Page 3
CONDENSING BOILER
CONTENTS Page
1. IMPORTANT INFORMATION 4
1.1 Gas Testing and Certification and CE Mark
1.2 Handling and Storing Appliance
1.3 System Installation
1.4 Warnings
1.5 Equipment Selection
1.6 Electricity Supply Failure
1.7 Protection Agenst Freezing
1.8 Boiler Installation in a Compartment or Cupboard
1.9 Boiler Casing
1.10 Condensate Drain
1.11 Pluming from Flue Terminal
1.12 Cleaning
1.13 Maintenance and Servicing
1.14 Replacement Parts
1.15 Continuous Improvements
4
4
4
4
4
4
4
5
5
5
5
5
5
5
5
2. OPERATING THE BOILER 6
2.1 Heating System and Boiler
2.2 User Controls
2.3 To Turn the Boiler Off
6
6
7
3. INSTALLATION, DESIGN & PLANNING INFORMATION 8
3.1 Important Notice
3.2 Technical Data of Boilers
3.3 Gas Supply
3.4 Electricity Supply
3.5 Central Heating and Water System
3.6 System/Boiler Pump
3.7 Flow rate
3.8 Bypass Valve
3.9 Domestic Hot Water Storage Cylinder
3.10 Boiler Location and Ventilation
3.11 Flue location and Ventilation
3.12 Heating System Controls
3.13 Condensate Drain
3.14 Water Treatment
8
9
11
11
11
16
16
16
16
16
17
18
18
18
4. BOILER INSTALLATION 19
4.1 Installation Preparation
4.2 Hanging Bracket Fixing
4.3 Boiler Fixing
19
19
19
5. ELECTRICAL WIRING 21
5.1 General
5.2 External Controls
21
21
CONTENTS Page
6. COMMISSIONING 24
6.1 General
6.2 Inital Lighting
6.3 Testing - Gas
6.4 Testing - Heating System
6.5 Testing - User Controls
6.6 Frost Protection
6.7 Instruct the User
24
24
24
24
24
24
24
7. SERVICING 25
7.1 General
7.2 Spart & Flame Sensing Electrodes
7.3 Burner
7.4 Combustion Chamber and Heat Exchanger
7.5 Condensate Drain
7.6 Inner Casing Panel Seal Check
7.7 Combustion Check
25
25
25
25
25
25
25
8. FAULT FINDING 26
8.1 Controller Display
8.2 Error / Fault Codes
8.3 Serial Software
8.4 Internal Wiring Diagram
26
28
29
32
9. REPLACEMENT OF PARTS 33
9.1 General
9.2 Spark & Flame Sensing Electrodes
9.3 Ignition & Flame Sensing Leads
9.4 Fan
9.5 Burner
9.6 Temperature Sensors
9.7 Heat Exchanger
9.8 Insulation
9.9 Overheat Thermostat
9.10 Fuses
9.11 On-Off Switch
9.12 Gas Valve
9.13 Controller PCB
34
34
34
34
34
34
34
34
34
34
34
10. SPARE PARTS 38
11. GAS BOILER COMMISSIONING CHECKLIST 39
11.TERMS & CONDITIONS OF TRADING 41
CONTENTS

Page 4
1.1. GAS TESTING AND CERTIFICATION AND CE MARK
These boilers have been tested and certified for safety and performance. It
is important that no alteration is made to the boiler unless it is approved in
writing by Gledhill Ltd.
The boiler meets the requirements of Statutory Instrument No 3083 i.e.
‘The Boiler (Efficiency) Regulations’ and therefore it is deemed to meet the
requirements of Directive 92/42/EEC. The product has been certified by the
Notified body Advantica 0087 and the production is certified by the notification
body BSI 0086.
The CE mark on this appliance shows compliance with:
(a) Directive 90/396/EEC on the approximation of laws relating to appliances
burning gaseous fuels.
(b) Directive 73/23/EEC on the harmonisation of laws of the Member States
relating to electrical equipment designed for use within certain voltage
limits.
(c) Directive 89/336/EEC on the approximation of the laws of Member States
relating to electromagnetic compatibility.
1.2. HANDLING AND STORING THE APPLIANCE
This appliance should be handled carefully to avoid damage and any manual
handling/lifting operations will need to comply with the requirements of the
Manual Handling Operations Regulations issued by the H.S.E.
During the appliance installation it will be necessary to employ caution
and assistance whilst lifting as the appliance or component exceeds the
recommended weight for a one man lift.
Take care to avoid trip hazards,slippery or wet surfaces.In certain situations it
may be necessary to use mechanical handling aids.
If the unit needs to be stored prior to installation it should be stored upright
in a dry environment and on a level base.
1.3. SYSTEM INSTALLATION
Any installation must be in accordance with the relevant requirements of the
current issue of Gas Safety (Installation and Use) Regulations, Local Building
Regulations,Local Water Company Bylaws and Health & Safety Document No.
635 –The Electricity atWork Regulations 1989.The detailed recommendations
are contained in the current issue of the following British Standards and Codes
of Practices: -
BS 5440 Pts. 1 & 2; BS 5449; BS 5546; BS 7074 Part 1; BS 6700; BS 6798; BS 6891,
BS 7593, IGE/UP/7/1998
1.4.WARNINGS
(a) Gas Leak or Fault
If a gas leak or fault exists or is suspected,turn the boiler mains electricity supply
off and turn off the gas supply at the meter. Consult your local gas company
or your local installation/servicing company.
IMPORTANT INFORMATION
(b) Clearances
If fixtures are positioned close to the boiler,space must
be left as shown in figure 3.10.2. Enough space must
also be left in front of the boiler to allow for servicing.
(c) Sheet Metal Parts
This boiler contains metal parts (case & components)
and therefore care should be taken when handling and
cleaning, with particular regard to edges.
(d) Sealed Components
This boiler uses fully premix burner with air/gas ratio
controller therefore the burner input i.e. CO and CO2
settings and the burner off set pressure are factory set
and sealed and require no onsite adjustments during
installation or routine servicing.
Under no circumstances the user should interfere
with the sealed components as this could result in
a potentially dangerous situations arising. If sealed
components in the appliance are replaced and/or re-
commissioned in the field then these must be done
strictly in accordance with manufacturer’s instructions
and these components must be re-sealed.
(e) Bench Mark Log Book
As part of the industry wide ‘Benchmark’ initiative
all Gledhill appliances now include a Benchmark
Installation, Commissioning and Service Record
Logbook. Please read this carefully and complete all
sections relevant to this appliance. Failure to do so
may affect warranty.
1.5. EQUIPMENT SELECTION
This information is provided to assist generally in the
selection of equipment.Responsibility for selection and
specification of our equipment must,however,remain
that of our customers and any expert or consultants
concerned with the installation(s). Therefore please
note that: -
(a) We do not therefore accept any responsibility for
matters of design selection or specification for the
effectiveness of an installation containing one of our
products.
(b) All goods are sold subject to our Conditions of Sale,
which are set out in the Appendix to this document.
1.6. ELECTRICITY SUPPLY FAILURE
(a) This boiler must be earthed and the boiler will not
work without an electricity supply.
(b) Reset any external controls to resume normal
operation of the central heating.

Page 5
CONDENSING BOILER
(c) Normal operation of the boiler should resume when the electrical supply is
restored. If the boiler does not resume normal operation turn the mains switch
off and on. If the boiler does not resume normal operation after this,the overheat
thermostat may have operated. The overheat thermostat would only operate
under abnormal conditions and,under these circumstances it would be advisable
to consult your installation/servicing company.
1.7. PROTECTION AGAINST FREEZING
(a) The boiler has built in frost protection programme as long as the electricity and
gas are left switched on.The boiler controller operates the burner and the system
pump when the temperature inside the boiler falls below 5ºC.
(b) Any other exposed areas of the heating and hot water system should be
protected by a separate frost thermostat.
(c) If the mains electricity and gas supplies to the boiler system are to be turned
off for any long periods during severe weather, it is recommended that the whole
system including the boiler should be drained to avoid risk of freezing.In this case
ensure that the immersion heater in the cylinder if fitted is switched off.
(d) If you have a sealed heating system,contact your installation/service company as
draining, refilling and pressurising MUST be carried out by a competent person.
(e) As a safety feature,the boiler will stop working if the condensate drain becomes
blocked. During freezing conditions this may be due to the forming of ice in the
condensate drain external to the house. Release ice blockage by use of warm
cloths on the pipe. Contact your installation/service company if the fault persists.
1.8. BOILER INSTALLATION IN A COMPARTMENT OR CUPBOARD
If the boiler is fitted into a compartment or a cupboard,it does not require ventilation
openings. However, do not use the compartment or cupboard for storage.
1.9. BOILER CASING
Do not remove or adjust the casing in any way, as the incorrect fitting may result
in incorrect operation or failure to operate at all.
1.10. CONDENSATE DRAIN
The condensate drain must not be modified or blocked (See section 3.13)
1.11. PLUMING FROM FLUE TERMINAL
This is a high efficiency-condensing boiler and hence flue gas temperature will be
low. Therefore like all condensing boilers this appliance will produce a plume of
condensation in cool weather.It is normal and not a fault condition,but this should
be taken into account when positioning the boiler.
1.12. CLEANING
This boiler contains metal parts and therefore care should be taken when handling
and cleaning, with particular regard to edges.
IMPORTANT INFORMATION
The boiler casing can be cleaned using a mild liquid
detergent with a damp cloth and then a dry cloth
to polish.Do not use any form of abrasive or solvent
cleaner as you may damage the finish.
1.13. MAINTENANCE AND SERVICING
This appliance must be serviced and installed by a
competent person e.g. CORGI Registered installer.
All CORGI registered installers carry a CORGI ID Card
and have a registration number.You can call CORGI
direct on 01256 372300.
For the continued efficient and safe operation of
the boiler, it is recommended that it is checked
and serviced at regular intervals.The frequency of
service will depend upon the installation condition
and usage, but in general, once a year should be
enough.
If this boiler is installed in a rented property, there
is a duty of care imposed on the owner of the
property by the current issue of the Gas Safety
(Installation and Use) regulations, Section 35.
The installation / service engineer should complete
the ‘Benchmark’ logbook on completion of
commissioning and service work.
1.14. REPLACEMENT PARTS
When replacing spare parts on this appliance,
remember to use only spare parts that you
can be assured to conform to the safety and
performance specification that we require. Do not
use reconditioned or copy parts that have not been
clearly authorised by Gledhill Ltd.
Free of charge replacement for any faulty
components are available from Gledhill Ltd during
the in-warranty period (normally 12 months).
After this the spares can be obtained direct from
Gledhill Ltd using the ‘Speed Spares’ service. Help
and advice is also available from ourTechnical Help
Line on 08449 310000.
Please quote the name and model of the appliance
when requesting for help or ordering spares. This
information will be on the front of the appliance
next to the main switch.
1.15. CONTINUOUS IMPROVEMENTS
In the interest of continuously improving the
Gledhill Boiler range, Gledhill Water Storage Ltd
reserves the right to modify the product without
notice and in these circumstances this booklet,
which is accurate at the time of printing, should
be disregarded.

Page 6
2.1. HEATING SYSTEM AND BOILER
(a) Sealed Systems
A sealed heating system must be filled and pressurised by a competent person.
Only light the boiler when you are sure that the system and the boiler have
been filled and pressurised.
The pressure should read at least 0.5bar, anything less than this figure could
indicate a leak and you MUST contact your installation / servicing company.
(b) All Systems
Check that the electrical supply to the boiler is ON at the external system
isolator. Set any remote controls as required.
This is a fan flued appliance and therefore the fan operation may be heard.The
boiler flow temperature is factory set at 77°C and is not user adjustable.(Note:
The boiler flow temperature can be adjusted between 55°C and 85°C by the
installer for special applications)
OPERATING THE BOILER

S3
S2
Set/Reset
-+
S1
Mains/Reset
Switch
$ $
0
I
Diagram 2.1
a1
a2
S3
S2
Set/Reset
-+
S1
Mains/Reset
Switch
$ $
0
I
Diagram 2.1
a1
a2
2.2. USER CONTROLS
The appliance control panel is shown in diagram 2.1. The appliance on-off
switch should be left in the ON position (indicated by flame symbol) for normal
operation otherwise the built in boiler frost protection will not function.
The two-digit display indicates the status of the boiler and the push buttons
are used for setting and resetting the controller as shown in diagram 2.2.
(a) Central heating and hot water
- Switch the boiler on-off switch to position‘ON’position indicated by a‘flame’
symbol and the dot D1 will begin to flash to indicate that the boiler controller
is active.
- Set the remote user controls e.g. programmer and room thermostat so that
hot water heating and/or central heating demands are active.
- When the boiler senses the heating demand,indicated by horizontal bar ‘a2’,
the boiler switches on the boiler pump (indicated by bar ‘a1’) and starts the
boiler firing sequence.
- When the boiler has lit, the dot D1 will stop flashing and will be on
constantly.
- If the boiler fails to ignite,the dot D1 will switch off and
dot D2 will be flashing or be on constantly (depending
upon the error type) and reset will be required.
- When the demand for boiler firing stops i.e. heat is
not required for space heating or hot water, the boiler
will stop firing and this will be indicated by flashing dot
D1 and bar a2 will switch off. After a period of about
3 minutes the boiler pump will switch off indicated
by bar a1.
(b) To Reset Boiler
Press reset button S1. If the dot D1 starts to flash and
the dot D2 switches off, the boiler has reset.If the fault
persists contact your installer/service provider.
2.3. TO TURN THE BOILER OFF
Turn the mains /reset switch to the off position
(indicated by disc). Turn the gas supply off at the gas
service cock if the boiler is to be out of use for some
time.

Page 7
CONDENSING BOILER
OPERATING THE BOILER
$IAGRAM"OILERDISPLAYINDICATION
$$ $$ $$
$$ $$ $$
FLASHING
FLASHING /NFLASHING
FLASHING /.
FLASHING FLASHING
v#ONTROLLERONSTANDBY
v"OILEROFF
v&ROSTPROTECTIONPROGRAM&ON
v"OILERPUMPON
v"OILERBLOCKINGLOCKOUTERROR
v2ESETREQUIRED
v&ROSTPROTECTIONPROGRAM&ON
v"OILERPUMPON
v"OILERBURNERISON
v"OILERINIGNITIONSEQUENCE
BOILERCONTROLTHERMOSTATSATISFIED
v"OILERHEATDEMANDPRESENT
v"OILERPUMPON
v"OILERHASLIT
v"OILERHEATDEMANDPRESENT
v"OILERPUMPON
v"OILEROFF
v(EATDEMANDNOTPRESENT
v"OILERPUMPOVERRUNON
/N

Page 8
3.1. IMPORTANT NOTICE
(a) The boiler is supplied in one pack. The flue and fixing jig are supplied
separately.
(b) This boiler is for use on G20 natural gas only. The boiler is certified to the
current issue of EN483 for performance and safety. It is important that no
alteration is made to the boiler, without written permission of Gledhill Ltd.
(c) Where no British Standards exist,materials and equipment should be fit for
their purpose and of suitable quality and workmanship.
(d)The installation of this boiler must be carried out by a competent person e.g.
CORGI Registered installer, must comply with the relevant requirements of :-
Manufacturer’s instructions supplied
• The Gas Safety (Installation and use) Regulations,
• The Building Regulations and local Water Company Bylaws.The Health and
Safety at Work Act, Control of Substances Hazardous to Health,The Electricity
at Work Regulations and any other applicable local regulations.
• The detailed recommendations are contained in the current issue of BS
5440 Pts. 1 & 2; BS 5449; BS 5546; BS 7074 Part 1; BS 6700; BS 6798; BS 6891, BS
7593, IGE/UP/7/1998
(e) When installing the boiler, care should be taken to avoid any possibility of
personal injury when handling sheet metal parts.
(f) Refer to Manual Handling Operations, 1992 regulations.
INSTALLATION DESIGN AND PLANNING INFORMATION
CONDENSATE
DRAIN
INSIDE WALL
FIXING FACE
BOILER
Centre Line
GAS
CONDENSATE
DRAIN
Diagram 3.1 Boiler Models GB30, GB25, GB20
Clearances From Fixed surfaces
Top
–
From ‘A’
:220mm
Bottom
–
From ‘B’
:200mm
Sides
–
From ‘C’
:20mm
Front
–
From ‘D’
:600mm
A
B
C
D
C
GAS
CONDENSATE
DRAIN
INSIDE WALL
FIXING FACE
F+R
FLOW
& RETURN
BOILER
Centre Line
GAS
CONDENSATE
DRAIN
Clearances From Fixed surfaces
Top
–
From ‘A’
:220mm
Bottom
–
From ‘B’
Sides
–
From ‘C’
:20mm
Front
–
From ‘D’
:600mm
A
B
C
D
C
130mm
85mm
150mm
140mm
580mm
100mm
100mm
150mm
70 mm
50mm
Cut flue terminal at
plain end to length
required allowing
40mm extra for
socket elbow joint
730mm
360mm
MM

Page 9
CONDENSING BOILER
INSTALLATION DESIGN AND PLANNING INFORMATION
3.2.TECHNICAL DATA OF BOILERS
The main dimensions and the clearances required for the boilers are shown in
diagram 3.1 for models GB30, GB25 and GB20 and diagram 3.2 for models GB15
and GB10.The technical data of the boilers is shown in tables 3.1 and 3.2.The boiler
data badge is positioned on the inner door.
The Seasonal Efficiency Domestic Boilers UK (SEDBUK) of Gledhill Boilers (all models)
is Class‘A’.The values used in the UK Government’s Standard Assessment Procedure
(SAP) for energy rating of dwellings.The test data from which it has been calculated
has been certified by Advantica.
CONDENSATE
DRAIN
INSIDE WALL
FIXING FACE
BOILER
Centre Line
GAS
CONDENSATE
DRAIN
Clearances From Fixed surfaces
Top
–
From ‘A’
:220mm
Bottom
–
From ‘B’
:200mm
Sides
–
From ‘C’
:20mm
Front
–
From ‘D’
:600mm
A
B
C
D
C
GAS
CONDENSATE
DRAIN
INSIDE WALL
FIXING FACE
F+R
FLOW
& RETURN
BOILER
Centre Line
GAS
CONDENSATE
DRAIN
Clearances From Fixed surfaces
Top
–
From ‘A’
:220mm
Bottom
–
From ‘B’
Sides
–
From ‘C’
:20mm
Front
–
From ‘D’
:600mm
A
B
C
D
C
140mm
85mm
150mm
140mm
580mm
100mm
100mm
210mm
70 mm
50mm
Cut flue terminal at
plain end to length
required allowing
40mm extra for
socket elbow joint
730mm
300mm
MM
$IAGRAM"OILER-ODELS'"AND'"

Page 10
Table 3.1. Connection, Electrical and Weight data of the boiler
Boiler Model
GB30, GB25, GB20 GB15, GB10
Overall dimensions including
flue spigot
Height (mm) 580 580
Width (mm) 380 380
Depth (mm) 360 300
Clear space required for
installation
Height (mm) 1000 1000
Width (mm) 420 420
Depth (mm) 500 440
Weight (kg) 29.5 24.5
Water content (litres) 1.5 1
Working pressure
(m wg / (bar))
Minimum 1.0/(0.1) 1.0/(0.1)
Maximum 30.0/(3.0) 30.0/(3.0)
Connections
Gas Rc1/2, (1/2in BSP) Rc1/2, (1/2in BSP)
Water 22mm copper 22mm copper
Condensate Drain 22mm plastic pipe 22mm plastic pipe
Electrical data
Electricity supply 230V, ~50Hz Fused at 3A 230V, ~50Hz Fused at 3A
Electrical rating 60W @230V ac 60W @230V ac
Internal fuse rate Main PCB 3.15AT Main PCB 3.15AT
Table 3.2.Thermal, combustion and gas data
Rating Boiler Model
GB30 GB25 GB20 GB15 GB10
Gross heat input (kW) Maximum 34.2 28.3 22.6 17.0 11.4
Minimum 10.0 8.5 6.8 5.1 4.6
Net heat input, Q (kW) Maximum 30.8 25.5 20.4 15.3 10.3
Minimum 9.0 7.7 6.1 4.6 4.1
Heat output, P Non condensing (kW) Maximum 30.2 25.0 20.0 15.0 10.0
Heat output
Condensing mode (kW)
Maximum 32.0 27.2 22.0 16.4 10.84
Minimum 9.8 8.4 6.6 4.9 4.4
Burner CO2 (%) at maximum rate Case off 9.0 - 9.6 9.0 - 9.6 9.0 - 9.6 8.8 - 9.4 9.0 - 9.6
Case on 9.2 - 9.8 9.2 - 9.8 9.2 - 9.8 9.0 - 9.6 9.2 - 9.8
Approximate Gas rate (m3/h)
- After 10min from cold Maximum 3.3 2.7 2.2 1.6 1.1
Off-set pressure at minimum rating (Pa) - 8.0 -10.0 -10.0 -8.0 -6.0
Minimum water flow rate (m3/h) 1.37 1.17 0.94 0.70 0.48
INSTALLATION DESIGN AND PLANNING INFORMATION

Page 11
CONDENSING BOILER
3.3. GAS SUPPLY
(a) The Local Gas Supplier should be consulted at the installation planning stage
in order to establish the availability of an adequate supply of gas.
(b) An existing service pipe MUST NOT be used without prior consultations with
the gas supplier.
(c) A gas meter can only be connected by the Local Gas Supplier or by his
Contractor.
(d) An existing meter should be of sufficient size to carryout the maximum boiler
input plus the demand of any other installed gas appliance, (BS 6891:1988). The
supply from governed meter must provide steady inlet working pressure of
20mbar (8in wg) at the boiler. See section Technical Data for the gas required for
each specific model.
(e) The gas supply line must be purged.WARNING: before purging open all doors
and windows and also extinguish any cigarettes, pipes and any other naked
lights.
(f) The complete gas installation must be tested.
3.5. CENTRAL HEATING AND WATER SYSTEM
The Gledhill boiler is suitable for use with both vented and unvented traditional
heating systems and also for use with the thermal storage systems e.g. Gledhill
BoilerMate OV and Gledhill BoilerMate SP (SysteMate).
Plastic Pipes
When plastic pipe is to be used for the heating system, this must be suitable for
the maximum pressures and temperatures for the intended application. The class
‘S’pipes and fittings are defined in BS 7279-1.
Some plastics are permeable to the oxygen and to prevent corrosion of system
components (e.g. heat exchanger) due to build up of oxygen, a barrier type pipe
must be used i.e. pipes incorporating a polymer barrier layer.
When plastic pipe is used,the first 2m of pipe work from the boiler (both flow and
return) must be in copper.
INSTALLATION DESIGN AND PLANNING INFORMATION
3.4. ELECTRICITY SUPPLY
(a) The boiler must be permanently connected
to a 230V~, 50Hz supply. This appliance MUST BE
EARTHED.
(b) All external wiring to the boiler must be in
accordance with the latest I.E.E.Wiring Regulation,
and any local regulations, which may apply.
(c) There must be only one common isolator for
the boiler and its control system, and it must
provide complete electrical isolation via a double
pole isolator fused at 3A maximum with a contact
separation of at least 3mm in both poles.
(d)The fused spur box should be readily accessible
and preferably adjacent to the appliance and it
should be identified as to its use.
(e) Alternatively the connection can be made
through an unswitched shuttered socket and 3A
fused 3-pin plug both to the current issue of BS
1363 may be used, provided they are not used in
a room containing bath or shower.
(f) In the event of an electrical fault after installation
of the appliance,preliminary electrical checks must
be carried out i.e. Earth Continuity, Short Circuit,
Polarity, and Resistance to Earth.
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Page 12
3.5.1. Open vented heating system
(a) The open i.e.vented heating system is shown schematically in diagram 3.3.
It is important that the relative positions of the pump,cold feed and the open
vent are as shown in diagram 3.3 to minimise the chances of air ingress and
pump over conditions arising.
(b) The cold feed must be 15mm minimum size. The 22mm (minimum) open
vent must rise continuously and be unrestricted.
(c) The boiler must be supplied from an unrestricted water supply taken from
feed and expansion cistern situated at a maximum height of 30 meters above
the boiler.
(d) A safety valve need not be fitted to an open vented heating system.
(e) A draining tap conforming to the current issue of BS2879,must be provided
at the lowest point of the system, which will allow the entire central heating
and hot water system to be drained.
(f) The overflow/warning pipe should be in 20mm internal diameter pipe of
suitable material for use in heating systems in accordance with BS 5449 (such as
copper).It should have continuous fall and discharge in a conspicuous external
position. It should not have any other pipework directly branched into it.
(g) The water level in the F & E cistern should be at least 250mm above the
highest point on the system including the radiators
INSTALLATION DESIGN AND PLANNING INFORMATION
3.5.2. Sealed heating system
(a) Design Standards
The sealed heating system is shown schematically
in diagram 3.4. The sealed system installation must
comply with the appropriate requirements of current
issues of BS5449, BS6759, BS6798 and BS7074.
(b) Safety Valve
A non-adjustable safety valve must be fitted to a sealed
system. It shall be pre-set with a lift pressure of 3 bar
and incorporate a seating of resilient material, a test
device and a connection to the drain
(c) Safety Valve Drain
The drain from a safety valve must be routed outside
the building and positioned so that any discharge can
be seen. It must not discharge above an entrance or
window or any type of public area and be clear of any
electrical fittings.
(d) Pressure Gauge
A pressure gauge with a set pointer and covering at
least 0 – 4 bar shall be fitted permanently to the sealed
system. It should be positioned where it can be seen
when filling the system.
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Page 13
CONDENSING BOILER
3.5.2. Sealed heating system(Cont)
(e) Expansion Vessel
A diaphragm type expansion vessel,conforming to
the current issue of BS4814 (See also BS7074 Parts
1 and 2) must be connected to the inlet side of
the circulating pump (see diagram 3.4) unless laid
down differently by the manufacturer.
The water content of the boiler is given in table 3.1.
The expansion vessel volume depends on the total
water volume of the system and the initial system
design pressure as shown below in table 3.3. For
any system an accurate calculation of vessel size
is given in the current issue of BS5449 and BS7074
Part 1. For example; A higher initial design charge
pressure requires a larger volume vessel.
The initial vessel charge pressure must not be
less than the static head of the system, that is the
height of the highest point of the system above
the expansion vessel.
(f) Water Makeup
Provision should be made for replacing the water
loss from the system using a makeup bottle
mounted in a position higher than the highest
point of the system, connected through the non-
return valve to the return side of either central
heating or hot water cylinder circuit.
Alternatively, provision for water makeup can
be made using a filling loop, in an accessible
position on the return, or an approved CA device
as discussed below.
(g) Filling a Sealed Heating System
Provision for filling a sealed system at low level
must be made and the method selected must
comply with the Water regulations.The temporary
filling loop method is shown in diagram 3.5 and the
CA-device method is shown in diagram 3.6.
The CA device normally requires a pressure
differential to operate and this should be taken
into account when selecting the device and the
system operating pressures.
For the temporary filling loop method there must
be no permanent connection to the mains supply,
even through a non-return valve.
INSTALLATION DESIGN AND PLANNING INFORMATION
Table 3.3 Expansion vessel volume required
Safety valve setting (bar) 3.0
Vessel charge pressure (bar) 0.5 1.0 1.5
Initial system fill pressure (bar) 0.5 1.0 1.5 2.0 1.0 1.5 2.0 1.5 2.0
Total system water content (l) Expansion vessel volume (litres)
25 2.1 3.5 6.5 13.7 2.7 4.7 10.3 3.9 8.3
50 4.2 7.0 12.9 27.5 5.4 9.5 20.6 7.8 16.5
75 6.3 10.5 19.4 41.3 8.2 14.2 30.9 11.7 24.8
100 8.3 14.0 25.9 55.1 10.9 19.0 41.2 15.6 33.1
125 10.4 17.5 32.4 68.9 13.6 23.7 51.5 19.5 41.3
150 12.5 21.0 38.8 82.6 16.3 28.6 61.8 23.4 49.6
Boiler
Return
1. Control/Isolating valve
2. Double check valve
3. Hose unions
4. Temporary connection
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Page 14
3.5.3. Gledhill BoilerMate OV Heating System
The Gledhill Boiler is also suitable for use with a Gledhill BoilerMate OV;
an integrated open vented heating system and mains pressure hot water
appliance. This appliance is supplied with factory fitted and wired system
controls and equipment e.g. pumps, valves etc. The BoilerMate OV uses a
directly heated open vented primary store and is suitable for only vented
heating systems as shown schematically in diagram 3.7. For further details
refer to Gledhill BoilerMate OV manual.
The BoilerMate OV acts as the neutral point of the system and therefore the
cold feed and open vent must be piped to the appropriate connections on
the BoilerMate OV.
A draining tap conforming to the current issue of BS 2879, must be provided
at the lowest point of the system, which will allow the entire central heating
and hot water system to be drained.
The overflow/warning pipe should be in 20mm internal diameter pipe of
suitable material for use in heating systems in accordance with BS 5449 (such as
copper).It should have continuous fall and discharge in a conspicuous external
position. It should not have any other pipework directly branched into it.
The height of the F & E cistern above the BoilerMate OV should not be greater
than 10m and the water level in the F & E cistern should be at least 450mm
above the highest point on the system including the radiators
INSTALLATION DESIGN AND PLANNING INFORMATION
Boiler
BoilerMate
250mm
Highest point
of the system
Warning/Overflow pipe
Open vent
Cold feed
Mains
cold supply
•No bypass is required in the boiler circuit
•Bypass valve on heating circuit not required unless the heating
circuit incorporates 2-port zone valve or TRVs on all radiators
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•
•
-

Page 15
CONDENSING BOILER
3.5.4. Gledhill BoilerMate SP Heating System
The Gledhill Boiler is also suitable for use with a Gledhill BoilerMate SP;an integrated
sealed heating system and mains pressure hot water appliance The BoilerMate SP
uses an indirectly heated open vented hot water only primary store. The central
heating circuit is suitable for sealed heating systems as shown schematically in
diagram 3.8. For further details refer to Gledhill BoilerMate SP manual.
When using the boiler with a BoilerMate SP, the pressure safety valve must be
fitted on the boiler flow pipe adjacent to the boiler. The expansion vessel should
be fitted adjacent to the BoilerMate SP and connected to the connector on the
top of the BoilerMate SP.
The sealed central heating system design and component selection and sizing
including filling arrangements should follow the guidelines discussed in section
3.5.2 ‘Sealed Heating Systems’.
Although the heating system is sealed,the primary store in the BoilerMate SP must
be filled via a feed and expansion cistern supplied with the appliance as shown
in diagram 3.8.The height of the F & E cistern above the BoilerMate SP should not
be greater than 10m.
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INSTALLATION DESIGN AND PLANNING INFORMATION

Page 16
3.6. SYSTEM / BOILER PUMP
The variable duty pump should be fitted on the flow pipe from the boiler
and have isolating valves on each side as shown schematically in diagrams
3.3 and 3.4.
The pressure loss characteristics of the boilers are shown in diagram 3.9.The
water flow rates and the boiler pressure losses at 11ºC and 20ºC temperature
differences are also tabulated below in table 3.4.
The variable duty pump should be set to give a temperature difference of no
greater than 20ºC between boiler flow and return to give minimum flow rate
through the boiler shown in table 3.4.High resistance micro bore systems may
require a higher duty pump.


Diagram 3 .9 Pressure loss characteristics of the boilers
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
0 100 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500
Flow rate (litres/h)
Pressure loss (mWG)
GB_10, GB_15
GB_20, GB_25, GB_30
GB-30:
30kW = 1280 l/h at 20K diff
GB-25
25kW = 1070 l/h at 20k diff
GB-20
20kW = 850 l /h at 20K diff
2.6 m
1.9 m
1.3 m
GB-15
15kW = 640 l/h at 20K diff
0.8 m
GB-10
10kW = 430 l/h at 20K diff
3.7. FLOW RATE
If it is necessary to alter the flow rate in a system,the system can be fitted with
a lockable balancing valve in the main flow or return pipes. The example is
shown as a valve ‘A’ in diagram 3.4.
The flow rate through the boiler must not be allowed to fall below the values
given in table 3.2 for the boiler model selected.
Table 3.4 Boiler pressure loss data
Boiler
Model
Temperature
difference (K)
Flow rate (Litres
per hour)
Pressure loss (m WG)
GB30 11 2342 6.66
20 1288 2.30
GB25 11 1951 4.79
20 1073 1.69
GB20 11 1561 3.22
20 858 1.17
GB15 11 1171 3.91
20 644 1.47
GB10 11 780 2.00
20 429 0.80
3.8. BYPASS VALVE
A bypass is not required on the central heating system
unless the system controls could allow the boiler and
the pump to operate when there is no flow.
When a bypass valve has to be fitted,it must be placed
at least 1.5 meters away from the boiler as shown
schematically in diagrams 3.3 and 3.4. An automatic
bypass valve is recommended.
3.9. DOMESTIC HOT WATER
STORAGE CYLINDER
Single feed indirect cylinders are not suitable.
The domestic hot water cylinder must be of the double
feed fully indirect coil type. It must be suitable for
working at a gauge pressure of 0.35 bar above the
safety valve setting.
The storage vessel does not have a vent to the
atmosphere i.e. unvented cylinder is used, then the
installation must comply with the Building regulations
and LocalWater Company bylaws.See also the current
issues of BS5546 and BS6700.
3.10. BOILER LOCATION AND VENTILATION
3.10.1. Boiler Location
The boiler may be installed in any room although
particular attention is drawn to the requirements of the
current issue of BS7671 with respect to the installation
of a boiler in a room containing a bath or a shower.
Any electrical switch or boiler control using mains
electricity supply should be so sited that a person using
the bath or a shower cannot touch it. The electrical
provisions of the Building Standards (Scotland)
Regulations are applicable to such installations in
Scotland.
These boilers are not suitable for fitting outdoors.
The boiler must be mounted on a flat wall, which is
sufficiently robust to take its total weight given in
table 3.1.
INSTALLATION DESIGN AND PLANNING INFORMATION

Page 17
CONDENSING BOILER
3.10.2. Clearances
The boiler should be positioned and installed so that at least minimum clearances
shown in diagram 3.10, required for servicing and correct operation are provided.
Additional clearances may be useful around the boiler for installation and
servicing.
For flue installations where external access is not practical, considerations should
be given for the space required to insert the flue internally, which may require
clearances larger than those specified in diagram 3.10.
220
20 20
200
5*
Flue
Front
600
5*
5*
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220
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5*
*
3.10.3.Timber Frame Buildings
If the boiler is to be installed in a timber frame building, it should be fitted in
accordance with the Institute of Gas Engineers document IGE/UP/7/1998. If in
doubt, ask local gas utility company or Gledhill Ltd.
3.10.4. Room ventilation
The boiler is room sealed, so when it is installed in a room or space, a permanent
air vent is not required.
3.10.5. Compartment ventilation
If the boiler is installed in a compartment, a permanent air vent Is not required.
However leave existing air vents.
3.11. FLUE LOCATION AND VENTILATION
3.11.1. Flue Position and Length
The standard horizontal flue is fitted onto the top of the boiler as shown in diagrams
3.11 and 3.12.The dimension “X”for the rear outlet flue and dimension“Y”for the
side outlet flue must be measured and compared against the standard flue supplied
to check if it is suitable.
An extended flue system can be installed with the addition of extension kits (see
section 3.11.3 Flue options).The flue system must always be designed and installed
to have a continuous fall towards the boiler of at least 3º to allow the condensate
to run to drain via the boiler.
3.11.2. Internal Flue Installation
The flue can be installed from inside the building
when access to the outside wall face is not
practical.
3.11.3. Flue Options
The concentric flue systems and kits available for
this boiler are listed below in table 3.4. Additional
accessories and flue systems are also available for
this boiler. See ‘Gledhill Boiler Flue Options Guide’
for configurations that are available.
Table 3.4 Concentric Flue Kits and Options
Description Part No.
Standard horizontal flue kit GT461
Vertical flue terminal kit – pitched AFB001
Flat roof flue kit AFB010
Ridge terminal flue kit AFB020
The concentric flue system can be extended to
a maximum equivalent length of 6.65 metres
(excluding flue terminal) after the flue elbow fitted
to the appliance.This can be horizontal or vertical
but the following allowances should be made for
each component fitted.
Description Equivalent
Length
2m Flue extension 2.0
1m Flue extension 1.0
0.5m Flue extension 0.5
45º Flue bend 1.5
90º Flue bend 1.9
INSTALLATION DESIGN AND PLANNING INFORMATION

Page 18
3.11.4.Terminal Position
The minimum acceptable siting dimensions for the terminal for obstructions,
other terminals and ventilation openings are shown in Gledhill Boiler Flue
Options Guide. The dimensions measured are from the edge of the terminal.
The terminal must b exposed to the external air, allowing passage of air across
it at all times.
This is a condensing boiler and therefore some pluming may occur from the
flue outlet.This should be taken in to consideration when selecting the position
for the terminal.
Carports or similar extensions of roof only,or roof and one wall,require special
consideration with respect to any openings, doors, vents or windows under
the roof. Care is required to protect the roof if it is made of plastic sheeting. If
the carport has a roof and two or more walls, then seek advice from the local
gas supply company before installing a boiler.
3.11.5.Terminal Guard
A terminal guard is required if a person could come into contact with the
terminal or the terminal could be subject to damage. The terminal guard is
required for horizontal flue terminals below 2m above the ground floor or
accessible by the general public from the windows, balconies etc.
If a terminal guard is required, it must be positioned to provide minimum
of 50mm clearance from any part of the terminal and be central over the
terminal.
A terminal guard for this boiler is shown in the Gledhill Boiler Flue Options
Guide and is available from Gledhill Ltd quoting part number GF199.
3.12. HEATING SYSTEM CONTROLS
It is recommended that a programmer and a room thermostat should control
the boiler when there is a demand for central heating and a programmer and
hot water store thermostat should control the boiler when there is a demand
for water heating.
The thermostatic radiator valves may be installed; however they must not be
fitted in a room where the room thermostat is located.(Note:All systems must
have at least one radiator that is not fitted with a thermostatic valve.)
The heating system controls must meet the requirements of the current issue
of the Building Regulations. For further information see: -
• The current issue of “Approved Document L1 – Conservation of fuel and
power in dwellings”
• GIL 59, 2000 : Central heating system specification (CheSS)
• GPG 302, 2001: Controls for domestic central heating system and hot water.
BRECSU.
3.13. CONDENSATE DRAIN
A plastic drainpipe must be fitted to the boiler to allow
discharge of condensate to the suitable drain.
A copper pipe is NOT suitable.
Condensate should, if possible, be discharged into
the internal household drainage system. If this is not
practical, discharge can be made externally into the
household drainage system or a purpose designed
soak away. See section 4 for further details.
Note: Condensate trap inside the boiler casing must
be manually filled with water after installing the boiler
(i.e. before the first firing) and before commissioning
the system.
For long-term corrosion protection, after flushing, an
inhibitor suitable for stainless steel heat exchangers
should be used. Refer to the current issue of BS5449
and BS7593 on the use of inhibitors in central heating
systems. The examples are Sentinel X100 and Fernox
MBI.
3.14. WATER TREATMENT
For optimum performance after installation of the new
system, the boiler and its associated central heating
system should also be flushed.
The flushing should be carried out in accordance with
BS7593:1992 using cleaner such as Sentinel X300 or
X400 or Fernox Superfloc.
In the case of an existing installation, the
system MUST be thoroughly flushed before
installing the new boiler. Power Flushing is
the preferred option for existing installations
because all high efficiency boilers tend to
have smaller waterways than traditional
boilers. A suitable system filter (e.g.Spirovent
SV3-025-T) fitted in the boiler return is
STRONGLY recommended in existing systems.
INSTALLATION DESIGN AND PLANNING INFORMATION

Page 19
CONDENSING BOILER
BOILER INSTALLATION
4.1. INSTALLATION PREPARATION
Unpacking Of Boiler
Important:With regards to the Manual Handling Operations,1992 Regulations,the
following lift operation exceeds the recommended weight for one man lift.
Stand the boiler carton upright.
Cut and remove the securing straps and lift off the carton sleeve. Place aside any
loose components until required.
Carefully lay the boiler on its back, remove the two front casing panel-securing
screws and lift off the panel from the two retaining lugs.
Remove the two inner casing panel-securing screws at the bottom of the front
panel, and then lift off the two retaining lugs.
4.1.1.Wall Template
A wall template is supplied with the boiler. This should be used to mark the boiler
fixings and flue outlets and for checking the minimum clearances required.
4.1.2. Flue Hole Cutting
The standard horizontal flue is designed with an internal fall of 35mm/metre
towards the boiler for disposal of condensate. If the standard flue length alone
is being used then the flue hole of diameter 105mm can be cut in the position
marked on the wall template.
For standard side flues the horizontal flue centre line on the wall template should
be extended to the side wall, and the vertical centre of the flue hole marked at
176mm from the back wall.
For installations with external access, a 105mm diameter core drill can be used.
For installations with internal access only a 125mm diameter core drill should be
used.
When using extension pipes with the horizontal rear flue, a core drill size of
125mm should be used to allow the extension pieces to slope at 35mm/metre
(2.5°) towards the boiler.
For extended side flues, the flue hole centre should be determined by extending
the dashed inclined line on the template to the side wall. This dashed line is drawn
at 35mm/metre (2.5°) rise from the boiler. Where this line reaches the side wall, a
horizontal line should be marked. The vertical centre line of the flue should then
be marked at 176mm from the back wall, see diagram 5.3.
To allow for the flue passing through the wall at this angle a 125mm hole should
be drilled irrespective of internal or external installation.
If necessary remove the wall template whilst drilling the flue hole.
4.2. Hanging Bracket Fixing
If previously removed,reposition the wall template
over the flue hole and mark the position of the
fixing holes for the hanging bracket.
Mark and drill the fixing holes and secure the
hanging bracket.
4.3. BOILER FIXING
Important: With regards to the Manual Handling
Operations, 1992 Regulations, the following lift
operation exceeds the recommended weight for
a one man lift.
Having previously secured the hanging bracket to
the wall,lift the boiler into position in the following
manner:-
Lean the top of the boiler slightly to the wall and
position just above the hanging bracket. Allow the
boiler to slowly move downwards until engaged in
the hanging bracket.
4.4. CONNECTIONS
4.4.1. Gas Connection
Before connection check the supply of local gas.
The gas supply can be connected from below.
4.4.2.Water Connections
Provision is made for the water connections to be
made from above the boiler.
The position is shown on the wall template.
Flush out the domestic hot water and the central
heating system before connecting to the boiler.

Page 20
4.4.3. Condensate Drain Connection
Before fitting the condensate drainpipe,remove and fill the condensate trap
with water and refit to the appliance.
The condensate will be slightly acidic and the condensate pipe should be run
in a high temperature plastic drainpipe material (e.g. PP, UPVC etc). Copper
tube MUST NOT be used and ‘push fit’ overflow pipe MUST NOT be used.
The actual outlet connection (shown opposite) is stepped to accept either
21 or 22mm O.D. pipework. The connections are designed to be a friction fit
and particularly with 21mm pipe it is important that the pipe is long enough
and pushed firmly home (use a quarter turn)
Internal pipe work should have a bore diameter no smaller than 20mm.
The external pipe work should be kept to a minimum,and have a bore diameter
no smaller than 32mm.
The pipe should not have any upward pipe runs and must fall at least 2º (1:20)
throughout its length towards the discharge point.
It is strongly recommended that the condensate pipe should be run internally
to the house soil or vent stack or to a waste pipe.
Alternatively the condensate may be discharged into a rainwater system,
external gully or a purpose-built soak away. Any local building control authority
requirements must be complied with.
It is recommended that the pipe should not be installed externally but if it is it
should be insulated and terminated below the grating level of the gully or at
least 50mm above the soak away to minimise the effects of freezing.
BOILER INSTALLATION
21mm
22mm
Section