Heatline SARGON 18S User guide

SARGON 18S / 24S / 30S
PRE-MIX
CONDENSING
SYSTEM BOILER
Installation, Servicing
and User Instructions

Installation of the Condensate Waste Hose
IMPORTANT
The condensate trap bottom part should be filled with 50 cc. of water before
operating the boiler.
1. When the boiler is mounted push the plastic hose supplied all the way onto the
condensate outlet to the bottom left hand corner of the boiler as shown in the diagram.
2. Cut the plastic hose to desired length and fit a plastic coupling to connect to your
plastic waste pipe.
NOTE: Removal of the condensate trap for cleaning purposes.
1. Pull off the plastic hose from the condensate trap.
2. Unscrew the bottom of the trap in an anti-clockwise direction by hand.
* The accessory for the condensate trap includes the hose.

Natural Gas
Heatline™ Sargon 18S / 24S / 30S Pre-mix Condensing System Boiler
British Gas Service Listing:
SARGON 18S G.C.No. 41-157-12
SARGON 24S G.C.No. 41-157-13
SARGON 30S G.C.No. 41-157-14
Notified Body
IMQ 51BP2750 Directive 90/396/EEC
51BP2751DR Directive 92/42/EEC
The manufacturer, in the continuous process to improve his products, reserves the right to
modify the data expressed in the present documentation at any time and without prior notice.
The present documentation is an informative support and it cannot be considered as a
contract towards third parties.
The Heatline™ range of heating boiler
are manufactured from high quality
materials, enabling reliability and
optimum performance.
Heatline™ are committed to the
continual development of their
appliances to ensure their customers
benefit from the latest advances in
combustion technology and energy
savings.
‘Benchmark’ Log Book, Boiler Registration & SEDBUK
As part of the industry-wide initiative the boiler comes complete with an Installation,
Commissioning and Service Record Log Book. Please read the Log book carefully and in
accordance with current legislation complete all sections relevant to the appliance and
installation. The details within the Log Book will be required in the event of any warranty work.
On completion the Log Book, which is found at the end of the Installation manual, must be left
with the end user and the relevant sections completed on each subsequent Service visit.
NOTE: You are also obliged to register the installation of this boiler with CORGI. Should you
wish to check the SEDBUK website for the rating of this boiler search under
DD HEATING or the boiler name and designation, e.g. SARGON 24S.

Contents
Section Page
Preface
1. Installation Regulations 3
2. Technical Data 4
3. Boiler Characteristics 6
4. Operation 6
5. General Installation 7
6. Appliance Sitting 9
7. Flue Terminal Location 10
8. Flue (General) 10
9. Electrical Connections 13
Wiring Diagram 14
10. Boiler Installation 15
11. Gas Supply 19
12. Filling the System 19
13. Control Panel Functions 20
14. Commissioning 23
15. Onboard Adjustments 24
16. Safety Devices 26
17. Routine Servicing 27
18. Component Replacement 30
19. Gas Type Conversion 37
20. Fault Finding Chart 38
Appendices
Appendix 1. Spare Parts List 41
Appendix 2. User Instructions 42
Appendix 3. Benchmark Logbook 48 -49

Preface
The Heatline™ Gas fired combination boiler meets the requirements of Statutory
Instrument The Boiler (Efficiency) Regulations’ and is deemed to meet the requirements of:
• Gas Appliance Directive 90/396/EEC
• Efficiency Directive 92/42/EEC
• Low Voltage Directive 73/23 EEC (modified from 93/68) and;
• Electromagnetic Compatibility Directive 89/396 EEC (modified from 93/68)
Heatline™ declares that the materials used in the manufacturer of this appliance are
non-hazardous and that no substances harmful to health are contained within the appliance.
Heatline™ accepts no responsibility for the unsatisfactory performance of the appliance or
flue arising from the failure to comply with the installation and user instructions. Incorrect
installation could invalidate your guarantee and may lead to prosecution.
If the appliance is re-sold or installation transferred the appliance must be re-registered with
Heatline in order to maintain the warranty.
The boiler must be installed in accordance with these instructions and the regulations
currently in force. Read these instructions carefully before installing or using the appliance.
Manual Handling: When manoeuvring the boiler always use safe techniques – keep your back
straight, bend your knees, don’t twist, move your feet. Avoid bending forwards or sideways and
keep the load as close to your body as possible. Where possible transport the boiler using a
suitable trolley, sack truck or get some assistance. Grip the boiler firmly and before lifting
establish where the weight is concentrated to determine the centre of gravity, repositioning
yourself if necessary.
Handling
This apliance is heavy, truck if possible and obtain assistance if required.
To remove the appliance:
1. Carefully slit or remove the sealing tape being careful not to scratch the appliance door.
2. Fully open the carton lid and remove any instructions and components
3, Read the instructions carefully before installation
of appliance.
4. Roll the carton onto its open face.
5. Lift the carton free of the inner packaging.
6. Remove the mounting bracked and valve package.
7. Stands the boiler on its base within the styrene block
and remove the top packaging piece.
8. If you wish to remove the stryene base lie the appliance
on its back to do so.
Warnings
1

2
The sign of approval.
This is a fragile piece of equipment. Do not drop.
The packed appliances may be stacked five high.
Do not crush the packaging as this may damage the appliance.
Store the appliance upright as indicated on the box.
The Signs on Box
Access, warnings and connections on the boiler The Signs on Boiler
230 V
Low Voltage Room Thermostat: This picture shows
the terminal block, which is located at the bottom left
hand side of the control panel cover, to which the room
thermostat must be fitted.
NOTE: This is a voltage free connection and no mains
power must be applied to these terminals. For mains
powered thermostat connection, see section 9.5.
Warning High Voltage! This sign is located on the back
of the control box housing warning of high voltages within
the control box. Turn off and isolate the appliance before
removing this cover.
NOTE: Take care as there may be residual voltage within
some components.
LOW VOLTAGE ROOM THERMOSTAT – This picture shows the terminal block, which is located at the
left corner on the rear of the drop down control box. Note these terminals are not intended to drive the
thermostat but simply connect across the switch that opens and closes as the thermostat operates.
NOTE – This is a voltage free connection and no power (AC or DC) should be applied to these terminals.
For mains powered thermostats see section 9.5.

1.1. This appliance must be installed in accordance with the Rules in Force by a competent
person or registered CORGI. engineer in accordance with the Gas Safety (Installation and Use)
Regulations. Failure to install this appliance correctly may invalidate your guarantee.
1.2. Your CORGI. registered engineer should carry a C.O.R.G.I. ID card containing their
registration number, which should be recorded in your BENCHMARK Log Book, which is
supplied within the Instructions. You can check the validity of this ID number by contacting
CORGI. on 0870 401 2300.
1.3. This appliance must be installed in accordance with the Gas (Safety and Use)
Regulations, current Building Regulations, Building Standards (Scotland), I.S.813 Installation
of Gas Appliances (Ireland), IEE Wiring Regulations (BS 7671), Health and Safety Document
No. 635 (Electricity at Work Regulations) and Local Water Authority Bye Laws.
1.4. On installation the following British Standards must also be considered:
•BS 6798 Specification for installation of gas fired hot water boilers of rated input not
exceeding 70kW.
•BS 5449 Central heating for Domestic Premises.
•BS 5546 Installation of gas hot water supplies for domestic purposes.
•BS 5440 Flues and Ventilation for gas appliances of rated input not exceeding 70kW
(Part 1 Flues)
•BS 5440 Flues and Ventilation for gas appliances of rated input not exceeding 70kW
(Part 2 Air Supply)
•BS 6891 Installation of low pressure gas pipe-work installations up to 35mm (R1¼
).
1.5. Due to the manufacturer’s continuous improvement policy the manufacturer reserves
the right to change any specification of the appliance or make modifications to these
instructions, which meet current regulations at the time of print. However, the instructions
must not be taken as overriding statutory requirements.
1.6. To ensure reliability and continued performance ensure that other components in
the system are also approved to relevant standards and that the appliance and system is
adequately protected and maintained on an annual basis.
For further information or advice contact Heatline™ Service & Technical Enquiries
in UK & IE on:
Service: 0870 777 8341
Spares: 0870 777 8402
Technical Help Line: 0870 777 8318
E–mail via our web site: www.heatline.co.uk.
1. Installation Regulations
3

2. Technical Data
SARGON 18S 24S 30S
Gas Category II 2 H 3+
Gas inlet pressure Natural Gas mbar 20 20 20
Gas inlet pressure Propane mbar 37 37 37
Heat Input (Qmax) (CH) kW 20.0 25 30.5
Heat Output (Pmax) (CH) kW 19.5 24.4 29.8
Heat Input (Qmin) (CH) kW 10.5 11.0 11.0
Heat Output (Pmin) (CH) kW 10.1 10.6 10.6
Useful efficiency at 100% load % 97.5 97.5 97.6
Useful efficiency at 30% load % 107.0 107.0 106.9
Gas Rate (Max) (NG) m³/h 2.12 2.54 3.18
Gas Rate (Max) (Propane) kg/h 1.57 1.97 2.4
Gas Rate (Min) (NG) m³/h 1.11 1.16 1.16
Gas Rate (Min) (Propane) kg/h 0.83 0.867 0.867
Power supply Input 230 V , 50 Hz
Gas Diaphragm (NG) mm 7.1 (white) 7.0 (white) 7.0 (white)
Gas Diaphragm (LPG) mm 5.4 5.4 5.4
Air Diaphragm (NG) colour Red
Air Diaphragm (LPG) colour Red
Max. power consumption Watts 175
Level of protection IPX4D
Maximum heating temperature ºC 84~85
Max. domestic hot water
temperature ºC 60
Operating pressure
PMS / Min Bar 8 / 0.5
Expansion Vessel Capacity litres 7
Expansion Vessel Pre-charge bar 0.5
Air Intake Pipe Diameter mm 100
Flue Pipe Diameter mm 60/100 concentric & 80/80
Twin
CO2 % at nom ±0.1% (NG) % 9.8 9.5 9.9
CO2 % at nom ±0.1% (Propane) % 10.4 11.0 10.8
CO2 % at min. ±0.1% (NG) % 10.0 10.0 10.0
CO2 % at min. ±0.1% (Propane) % 10.3 10.9 10.8
Output mass (NG) g/sec 8.77 11.17 12.94
Output mass (Propane) g/sec 8.76 10.69 12.70
Nitrogen oxide (NOx) emissions at
max. heat input
NOx
Class 5 5 5
Nitrogen oxide (NOx) emissions at
max. hot water input
NOx
Class 5 5 5
Combustion products temperature
(max.) ºC 75 71 71
Case Dimensions mm 330(d) x 430(w) x 720(h)
Net weight kg 35 36 37
Gross weight kg 38 39 40
4
*Technical values are given by Notified body.

5
Key
1 – Flue Sensor
2 – Thermal Fuse
3 – Heat Exchanger
4 – Ionisation Electrode
5 – Ignition Electrode
6 – Fan Group (Fan, Air Gas Mixer, Ring)
7 – Expansion Vessel
8 – Ignition Transformer
9 – Overheat Safety Thermostat
10 – Central Heating Temperature Sensor (Flow)
11 – Pressure Relief Valve
12 – Gas Valve
13 – Pressure Sensor
14 – Pump
15 – Return Hydroblock
16 – Central Heating Temperature Sensor
(Return)
17 – Condensing Trap
18 – Burner
19 – Plastic Flue Channel
20 – Automatic Air Vent
21 – Pressure Relief Valve
Figure 1
Valves
A - Heating Flow (22mm) Red
B - Gas Inlet (22mm) Yellow
C - Heating Return (22mm) Blue (with filter)
Figure 1a
CD E F G H
BOTTOM VIEW
C = 39mm D = 65mm E = 86mm
F = 86mm G = 65mm H = 64mm
Figure 1b
21
A B C

3.1 The Sargon 18S / 24S / 30S are fan flued, wall-mounted system boilers that supplies
heating and possibly domestic hot water via a storage cylinder. Being room sealed the boiler
may be installed in any room without the need for purpose made ventilation. However, if the
boiler is installed in a compartment it is recommended that the compartment is ventilated for
cooling purposes. A functional diagram of the boiler’s principal components is given in figure 1.
3.2 An electronic control unit, consisting of a PCB and separate ignition module provides direct
burnerignitionandflamesupervisionalongwithcontinuousmodulationoftheburner’sgassupply.
3.3 An interface unit, which includes boiler adjustment potentiometers
and fault display provides easy adjustment and fault diagnosis.
3.4 Heat transfer of heat to the boiler’s primary hydraulic circuit is obtained via a primary,
gas to water heat exchanger within a hermetically sealed combustion chamber. A 24
volt, modulated speed fan blows the gas/air mixture into the combustion chamber
and expels the products of combustion to outside air via an associated flue system.
3.5 An integral pump located in the boilers main hydraulic circuit circulates water
through the primary heat exchanger to the central heating circuit. In the event of
reduced or interrupted water circulation in the central heating circuit, an automatic
system by-pass should be fitted as far away from the boiler as possible. Note: It is
no longer permissible to utilise a non-thermostatic controlled radiator as a by-pass.
3.6 Room temperature can be controlled by the use of an external room thermostat
and thermostatic radiator valves. Note connection of the room thermostat is
dependant on the operating voltage of the thermostat. See section 9.4 & 9.5 for details.
3.7 The boiler incorporates an integrated clock, which allows the setting of central heating
periods (See the User Instructions, Boiler Controls for details) and the boiler’s control panel
incorporates an LCD display, which indicates the state of operation and fault defect codes.
4.1 Using the operating switch the boiler can be set to operate central heating.
4.2 DOMESTIC HEATING MODE:
When the Control is set to “ON” and a heating demand is requested, (power is on, the
timer and thermostat are calling for heat) the boiler will fire automatically. The integral
pump is then energised and hot water from the boilers primary circuit is circulated
around the central heating systems pipe-work and radiators. When the demand for
central heating is no longer present, either the thermostat reaches temperature or the
time clock reaches the end of its set period, the burner will shut down and the boiler will
revert to stand-by, waiting to respond to the next heating demand. The pump will continue
to operate for a short period of time to dissipate any excess heat from within the boiler’s
heat-exchanger.
3.Boiler Characteristics
6
4. Operation

4.1 Using the operating switch the boiler can be set to operate either on domestic hot water
only or domestic hot water and heating.
Note: Domestic hot water demand draws preference over heating. During heating periods
the boiler will automatically revert back to heating mode, after a draw off of hot water, but
there will be a 45sec delay if the No.S3 dipswitch is set to the OFF position. See figure 19.
4.2 Depending on demand water is either diverted via the diverter valve to the secondary
water-to-water heat exchanger for domestic hot water or directly to the heating system.
4.3 DOMESTIC HEATING MODE:
• When the Control is set to “Winter” mode and a heating demand is requested,
(power is on, the timer and thermostat are calling for heat) the boiler will fire automatically.
The integral pump is then energised and hot water from the boilers primary circuit
is circulated around the central heating systems pipe-work and radiators. When the demand
for central heating is no longer present, either the thermostat reaches temperature or
the time clock reaches the end of its set period, the burner will shut down and the boiler will
revert to stand-by, waiting to respond to the next heating or hot water demand. The pump
will continue to operate for a short period of time to dissipate any excess heat from within
the boiler’s heat-exchanger. If during the heating period there is a call for hot water this
will take preference over heating. When satisfied, the boiler will then supply the heating
demand as required. Note there will be a delay of 45sec delay depending on how the boilers
dipswitches are set. See section 15.3 for details.
4.4 DOMESTIC HOT WATER MODE:
• When the Control is set to either the “Summer” or “Winter” mode and there is a request for
hot water (a hot water faucet is opened) the boiler will fire automatically. The integral pump
is then energised and hot water from the boilers primary circuit is circulated around
the water to water heat-exchanger, irrespective to any demand for heating, giving up its heat
to the domestic hot water. When the faucet is closed the pump will continue to operate for
a short period of time to dissipate any excess heat within the boiler’s heat-exchanger
into the heating circuit and after a 45sec delay will revert back to the heating mode
if required.
5.1 Installer Testing & Commissioning Tips
•The installer shall instruct the user in the operation of the boiler, safety devices
contained within the boiler and instruction on the location of the filling loop and how to
re-pressurise the system if the water pressure falls. The installer should then hand over
the instructions indicating the included Benchmark Log Book that has been completed.
4. Operation
5. General Installation
7

5.2 The boiler is designed to operate on fully pumped, pressurised sealed systems operating at
a maximum of 3bar pressure and maximum design flow temperature of 85°C.
5.3 The boiler’s integral expansion vessel is pre-charged to a pressure of 0.5 bar and will
accommodate a system volume of 125l at an average water temperature of 75°C and maximum
system pressure of 3 bar. If the system volume is more than 125 l an additional expansion
vessel must be fitted to suit the size of the system. A typical installation of an additional
pressure vessel is shown below in figure 2 below.
NOTE: The filter valve must be fitted to the boiler return at the right of the boiler.
5.4 The heating circuit should be designed and balanced to give a 20°C temperature rise across
the boiler flow and return.
5.5 When fitting a new boiler to an existing system the system must be thoroughly flushed in
accordance with the recommendations of BS7593:2006 prior to installation.
NOTE: Also that the gas supply pipe to the boiler from the meter should be in 22 mm copper.
5.6 It is recommended that the system should be protected by a proprietry anticorrosion
inhibitor.
5.7 On installation it is important to ensure that the heat exchanger is not a natural collecting
point for air and where possible, the system pipe work should have a gradient to ensure any
excess air is carried naturally to other purpose made, air release points.
5.8 The system’s water must always be allowed to circulate whenever the circulation pump is
running. An automatic by-pass must be provided.
NOTE : It is no longer permissible to use non-thermostatic radiator valves to allow by-pass
through a radiator.
8
Figure 2

5.9 In high water volume systems or under floor heating systems, see section 15.2, where
prolonged operation of the boiler is expected at temperatures below 60°C, a by-pass must be
installed on the boiler outlet in order to prevent condensation forming inside the boiler body.
Failure to comply with this requirement will invalidate the manufacturer’s guarantee.
5.10 The pressure relief discharge must be directed away from any electrical equipment or
where it could cause a hazardous situation.
5.11 In order to drain the complete system efficiently it is recommended that drain cocks
(compliant to BS2879) are fitted at the lowest points in the system pipe-work.
5.12 Where cold water mains are fitted with a water meter, check valve(s) or loose jumper
stopcock, you may need to fit a domestic hot water mini-expansion vessel in order to avoid
water hammer.
5.13 To obtain the best hot water performance from your boiler it is suggested that supplies to
taps are run in 15mm copper, as short as possible and where practical, be insulated to reduce
heat loss.
5.14 The boiler incorporates a frost protection thermostat. Therefore if the boiler will not be
used for long periods of time during cold weather, in order to avoid freezing the electric supply
must be left ON and all the central heating isolation valves must be left open. The internal
frost thermostat will then operate the boiler if the temperature falls too low. However, if the
electrical supply is to be turned off the boiler, the heating system and domestic hot water
circuit must be drained.
9
6. Appliance Sitting
6.1 If the boiler is to be installed in any room or compartment, it does not require any
purpose made ventilation for combustion air. If sited in a room containing a bath or shower
then particular reference is drawn to the current I.E.E. Wiring Regulations, local Building
Regulations or any other local regulations currently in service.
6.2 The boiler is not suitable for external installation unless protected by a purpose made
building such as a boiler house.
6.3. The following clearances are recommended for installation purposes; 200mm above,
300mm below and 50mm at each side. 600mm is required at the front but this may be upon
opening a cupboard door.
6.4 Flammable fluids and materials must be stored at least 1m away from the boiler.
6.5 The wall on which the boiler is mounted must be sufficiently strong to support the weight
of the boiler.
6.6 A corrosion resistant or plastic condensate drain pipe must be fitted to allow discharge of
condensate to a drain or soak away.
Where possible condensate should be discharged into the household internal drainage
system. If this is not practical, discharge can be made into an external drain. If neither of
the above options are possible then condensate must be discharged into a purpose designed
soak way.
NOTE: It is recommended that any external condensate pipe is insulated and increased to
32mm diameter in order to prevent the condensate from freezing.

6.7 For compartment installation the requirements of BS6798 and BS5440: Part 2 must be
met.
•The compartment must be of sufficient size to permit access for inspection and
servicing or the removal of the boiler and any ancillary equipment.
•Any space used for airing clothes or storage must be separated from the appliance by
a non-combustible partition. Where the partition is formed from perforated material, then
the major dimension of the apertures shall not exceed 13mm.
•No combustible surface must be within 20mm of the boiler casing without protection.
•There must be 20mm clearance between the compartment door and boiler case.
•Where the boiler’s flue pipe passes through the airing space, it must be protected by
a non-combustible sleeve or fire stop having a minimum clearance of 20 mm between
the flue pipe and sleeve. In addition, if the flue pipe passes through the partition then
the clearance gap of the flue pipe or its guard with the partition must not exceed 13 mm.
6.8 When the boiler is intended for use with LPG it must not be installed in a room or internal
space below ground level.
7.1. The flue terminal must be sited with minimum clearances as specified in Figure 3. Note
if pluming becomes problematic or causes a nuisance a plume management kit is available
from your stockist.
7.2. Current regulations and standards require a terminal guard to be fitted where the
terminal is accessible to touch or at risk of being damaged. All wall mounted terminals sited
within 2m of the level which people have normal access, should be adequately protected with
a suitably sited guard.
7.3. Where the flue terminates within 1m of a plastic or painted gutter or within 500mm
of painted eaves then protection should be provided in the form of an aluminium
shield at least 1m in length, fitted to the underside of the gutter or painted surface.
7.4. The flue should not be sited where the condensate “plume” may give rise to a nuisance
factor under certain weather conditions.
NOTE: If you have difficulty siting the flue in an appropriate location your supplier will be happy
to supply a “anti-plume management kit”, which discharges the flue products at a higher level.
8.1. The boiler utilises a concentric flue arrangement, which consists of a 60mm-diameter
inner flue and 100mm-diameter outer air inlet duct, which comes in either horizontal or vertical
arrangements. However, for greater flexibility flues are available as 80/80mm twin pipes and
in circumstances where the plume may cause a nuisance horizontal and vertical
anti plume kits available.
NOTE: Only use approved Heatline flue products with this boiler, which can be sourced from
the supplier of your boiler or Heatline stockist.
8.2. The standard 705+/-5mm flue (figure 5) is not supplied with the boiler and should be
purchased separately from your supplier. This flue may be routed to the rear, left or right
of the appliance by means of the 90° degree bend, which is supplied in the flue kit (figure 4).
The bend is connected to the boiler using the screws provided and sealed with the gasket.
10
7. Flue Terminal Location
8. Flue (General)

11
Figure 4
Figure 5
8.3. The 60/100mm horizontal flue system
may be extended up to a maximum of
5.0m, excluding the initial 90° bend, using
additional spare components available
from the supplier of your boiler or Heatline
stockist. Please note only use approved
Heatline flue products with this boiler. (Flue
type : C13 - C33 - C43 - C53)
8.4. A vertical 60/100mm flue kit is also
available (figure 6), which can be extended
up to a maximum of 5.0m, excluding the
initial boiler connection, using additional
components available from the supplier of
your boiler or Heatline stockist. Please note the terminal is suitable for a flat or pitched roof and
only approved Heatline flue products can be used with this boiler. The connection of the vertical
flue system is similar to the Horizontal flue connection. The system is connected with screws to
the boiler and the vertical extension pipes and roof terminal are connected by clips.
8.5. The 80/80mm twin flue pipe system may be extended up to a maximum of 20m in any
combination of horizontal or vertical configuration using additional spare components available
from your boiler supplier or Heatline stockist.
NOTE: When such a system is used it is necessary to have all joints accessible for inspection.
8.6. The anti-plume kit comprises of a 710mm horizontal section with elbow to connect the
1m vertical condensing tube, which has a horizontal or vertical terminal dependant on your
requirements. The maximum length of horizontal flue including the terminal but excluding the
initial elbow from the boiler and 1m vertical condensing tube is 4m.
Figure 6
NOTE: For each additional 90º elbow ( or
two 45º elbows) used the maximum flue
length must be reduced by 1.5 m.
WARNING !
ONLY A HEATLINE APPROVED FLUE IS TO
BE USED WITH THIS PRODUCT. FAILURE
TO COMPLY WITH THIS REQUIREMENT WILL
INVALIDATE YOUR GUARANTEE AND MAY
LEAD TO A DANGEROUS SITUATION.

12
Minimum Separation Distances for Flue Terminals
Location
(see diagram)
Description Clearance
(mm)
A Below an opening (See Note 1) 300
B Above an opening 300
C Horizontally to an opening 300
D Below gutters, soil pipes or drain pipes 75
E Below eaves 200
F Below balcony or car port roof 200
G From a vertical drain pipe or soil pipe 150
H From an internal or external corner or to a boundary alongside the termi-
nal (See Note 2)
300
I Above ground, roof or balcony level 300
J From a surface or a boundary facing the terminal (See Note 2) 600
K From a terminal facing the terminal 1200
L From an opening in the car port into the building 1200
M Vertically from a terminal on the same wall 1500
N Horizontally from a terminal on the same wall 300
P From a structure on the roof or another roof terminal 600
Q From a vertical flue terminal to an adjacent wall 300
R From a vertical flue terminal to an adjacent wall which includes an open-
ing window (See Note 3)
1000
Notes: 1. An opening here means an opening element, such as an openable window, or
a fixed opening such as a air vent. However, in addition, the outlet should not
be nearer than 150mm to an opening into the building fabric formed for the
purpose of accommodating a built in element, such as a window frame.
2. Boundary as defined in the Building Regulations (England & Wales) or the
Building Standards (Scotland) Regulations.
3. Where the wall adjacent to a vertical flue terminal includes an opening win-
dow, the clearance between the terminal and any part of the opening window
must not be less than 1000 mm.
P
R
Q
Q
J
H
L
F
G
I
A
B
C
D,E
H
H
N
M
K
Q
Boundary
Boundary
Figure 3
Internal corner
External corner
Double corner

13
9.1 The boiler is supplied factory wired complete with 1.5 m of mains fly lead. All electrical
connections to the mains supply must be made in full accordance with the current I.E.E. or
other local regulations.
9.2 The boiler must be connected to an effective earth system. Using the cable supplied
the boiler may be connected via a 3 amp fused three pin plug to an unswitched shuttered
socket outlet. However if the boiler is installed in a room containing a bath or shower
regulations dictate that disconnection must be incorporated in the fixed wiring with a switch
provided for disconnection from the mains supply having a contact separation of at least
3 mm on all poles and fused at 3 amp.
9.3 The point of connection must be readily accessible, at a distance no further than 1.5m
adjacent to the appliance and provide complete electrical isolation for the boiler and control
system.
9.4 The low voltage room thermostat terminal block is located behind the plastic cover on
the left hand side (figure 7). On connection of a voltage free room thermostat to the boiler,
the factory fitted bridge across the room thermostat terminal connectors must be removed.
If a mains voltage thermostat is to be used then please refer to 9.5 below and the electric
wiring diagram in figure 8.
9.5 Mains powered thermostats must be connected directly to the mains circuit board as
indicated in Figure 8 where connection of the thermostat is to the terminal block within
the control box. If using this connection the link wire across the terminal block shown
in figure 7 must be removed.
9.6 Ensure that the polarity of the mains connection is correct as reversed polarity may
cause the appliance to malfunction.
9.7 While the boiler’s main pcb, pump, three-way valve and gas valve are supplied at 230V
a.c., all other components and associated circuits are supplied at low voltage.
9.Electrical Connections
Warning!:
On no account must any
mains voltage be applied to
any of the terminals on the
heating control connection
plug.
Figure 7

14
9.8 On connecting the mains electrical supply to the boiler, it is essential to ensure that
electrical safety checks for earth continuity, earth resistance, polarity and short circuit are
carried out prior to making the final connection. A diagram of the boiler’s electrical circuit is
given as figure 8.
Fuse ratings: 2AT
Figure 8
Open Therm On / Off
Low Voltage Room
Thermostat
Mains powered
thermostat connections

15
TOP
BOTTOM
10.1 Prior to installing the boiler check the contents of the carton: Appliance, Valves, Wall
Hanging Bracket, Mounting Template Service, Installation and User Manual, which includes
the Benchmark Log Book and Guarantee Card. The boiler dimensions are given in figure 10.
10.2 Ensure that the boiler is suitable for the gas supply by checking the data plate, which
is situated on the inside of the control panel door, and that the system and chosen boiler
position is in accordance to Sections 5, 6 and 7 of these instructions.
10.3 Position the supplied template on the wall, ensuring it is level both vertically and
horizontally. (figure 10) Mark the boiler wall bracket fixing positions and flue outlet position
(rear flue only). For flue side exit from the boiler - Mark the horizontal flue centre line on the
rear wall. Extend the horizontal line to the side wall allowing a 3° decline back (if required,
see note below) towards the boiler, to enable condensate to drain back through the boiler.
Mark the flue centre vertical line. ( figure 11)
NOTE : Some flues may have the 3° built in and as such these flues may be installed in a
horizontal position.
Figure 9
Figure 10 Figure 11
A: 430 mm
B: 132 mm
10. Boiler Installation

16
10.4 When cutting the flue hole it is recommended that a 105mm diameter core drill is used
where both internal and external access for the flue installation is available. Where only
internal access is available a 125mm diameter core drill should be used. (Note: Please take
adequate precautions to prevent debris entering the boiler via the flue outlet).
10.5 Using a 8·5mm drill bit, drill the holes for fixing jig (optional) and hanging bracket.
Locate and secure the supplied wall mounting bracket and fixing jig in position (figure 12).
Figure 12
10.6 Mount the boiler onto the fixing bracket via the boiler mounting slots, (figure 12).
10.7 Connect isolation valves to the boiler ensuring the washers are fitted correctly.
NOTE: Refer to Figure 1 which shows the correct location of each valve.
10.8 Condensing type boilers must be connected to an appropriate drainage system either:
a. A corrosion resistant or plastic drain must be fitted to allow discharge of
condensate to a drain, see figure 13a.
b. Discharged into the internal household draining system. If this is not practical,
discharge can be made externally into the household drainage system or a purpose designed
soak away.
10.9 Using 50cc of water prime the condensate by either removing the bottom of the trap
using an appropriate allen key or via the inner flue duct at the top of the boiler.
Figure 13a
Figure 13b