Radiant RK 25 User manual

SEDBUK BAND A
Installation, operating, commissioning and maintenance instructions .
CE 0694 TA05A140.A0307
Technical specification RADIANT BRUCIATORI S.p.A. Montelabbate (PU) ITALY ENGLISH
Instruction Manual
for model
RK 25
Premix condensing system boiler

CONTENTS
1. General information
1.1 General warnings pag. 1
1.2 Product conformity 3
2. Technical characteristics
2.1 Technical data 4
2.2 Dimensions 5
2.3 Internal parts of the boiler 6
2.4 Water circuit 7
2.5 Circulation pump head/flow graph 8
2.6 Printed circuit board – Technical characteristics 9
2.7 Control panel 9
3. Installation (authorised personnel)
3.1 Reference standard 10
3.2 Boiler room – installation requirements 11
3.3 Unpacking 11
3.4 Installation boiler 12
3.5 Water connections 13
3.6 Central heating circuit 14
3.7 Condensate drain 15
3.8 Gas connection 16
3.9 Electrical connections 17
3.10 Flue connections 19
4. Commissioning the appliance (authorised personnel)
4.1 General warnings 24
4.2 Filling the system 25
4.3 Flushing the system 26
4.4 Filling the condensate trap 26
4.5 Starting up the boiler 27
5. Regulating the appliance (authorised personnel)
5.1 Parameters table 28
5.2 Setting the parameters 29
5.3 Gas Data 36

CONTENTS
6. Maintenance (authorised personnel)
6.1 General warnings pag. 37
6.2 Boiler inspection 37
6.3 Accessing the boiler 38
6.4 Flushing out the primary side 38
6.5 Draining the central heating and domestic hot water system 39
6.6 Maintenance operations 40
6.7 Wiring diagrams 46
6.8 Troubleshooting 53
6.9 Diagnostics . 54
6.10 Parts list 55

GENERAL INFORMATION
TA05A140.A0307 1
1. GENERAL INFORMATION
1.1 General warnings
Professionally qualified personnel in accordance with current laws and standards and in line with the
manufacturer’s instructions must install the appliance.
In GB, the installation must be carried out by a CORGI Registered Installer. To check for authorised
qualified engineers please contact CORGI 01256-372400. It must be carried out in accordance with the
relevant requirements of the:
- Gas Safety Regulations;
- The appropriate Building Regulations either The Building Regulation, 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 shoud be made to the relevant British Standards
Code of Practice.
The commissioning of the boiler and any subsequent works carried out on the appliance must be
effected by an appropriately qualified technician or an approved Radiant Helpline Service Centre.
The appliance must be used solely for the purpose for which it has been designed and manufactured:
central heating and domestic hot water production. Any other use is deemed as improper and as such
dangerous. Under no circumstances will the manufacturer be held responsible for damage or injury to
persons or animals caused by errors in the installation and/or use of the appliance, or through non-
compliance with current local and national standards and/or the manufacturer’s instructions.
The installation, operation and maintenance manual forms an integral and essential part of the product
and must be kept near the appliance always.
This Manufacturer Installation and Maintenance manual must not be removed on completion of the
installation; must be kept in a safe place and made available for future reference. This Manual must be
left along with the Benchmark commissioning booklet with the boiler as Regulation 29 of the HSC Gas
safety (installation and use) Regulations 1998.
The warnings contained in this chapter have been written for the appliance user, the installer and the
service engineer.
The “operating instructions” chapter of this manual must be read carefully as it provides information on
the operation and the operating limits of the appliance.
This appliance must be used exclusively in an un-vented central heating system.
•After the removal of all the packaging, check that the appliance has not been damaged. In case of doubt, do not
attempt to use the product but refer to the supplier. Packing materials (cardboard box, wooden crate, nails, staples,
plastic bags, polystyrene, etc.) must not be left within reach of children in that these items represent a potential hazard
and must be disposed of in a responsible manner.
•Before carrying out any cleaning or maintenance operations, disconnect the appliance from the mains electricity
supply by switching off at the main switch and/or any other isolating device.
•Do not obstruct the air intake or flue exhaust grills.
•Do not obstruct the air intake or flue exhaust terminals.
•In the case of a fault and/or malfunction in the appliance, shut down the system. Do not interfere with or attempt any
repairs. Call for professionally qualified technical assistance only. Radiant Helpline UK 0870 770 0414
•Any warranty repairs to the appliance must be carried out exclusively by the manufacturer’s authorised service centre
using original spare parts. Non-compliance with the above requirements may compromise the safety of the appliance
and invalidate the warranty. In order to guarantee the efficiency of the appliance and its correct operation, it must be
serviced regularly by professionally qualified personnel in line with the manufacturer’s instructions.
•When the appliance is no longer required for use, any parts that may constitute potential sources of danger must be
rendered harmless.

GENERAL INFORMATION
TA05A140.A0307 2
•Only original accessories or optional extras (including electrical parts) must be used with the appliance.
•Should there be a smell of gas present in the room where the appliance is installed, DO NOT attempt to activate any
electric switches, telephones or any other equipment that may cause sparks. Open doors and windows immediately to
create a current of air and ventilate the room. Shut-off the main gas supply valve (at the meter), or on the cylinder in
the case of bottled gas, and call an authorised service centre.
•Do not attempt to interfere with the appliance in any way.
•As dictated by current legislation, this appliance must be installed exclusively by qualified personnel. Before
starting the boiler for the first time, make sure that it is connected to a water supply and central heating system
compatible with its performance characteristics.
•The room must be ventilated by means of an air intake positioned at floor level and protected with a grill. Make sure
the grill does not reduce the passage section.
•The air inflow from adjacent rooms is allowed providing that those rooms are in depression with respect to the
atmosphere and that there are not fireplace or fan installed. When the appliance is installed outdoor, i.e. on
balcony or terrace, make sure it is not directly exposed to atmospheric agents to prevent any damage to components
which would lead to a warranty invalidation. It is recommended to provide the boiler with a protective casing/box
against bad whether conditions.
•Check the technical data reported on the packing and on the data plate located on the inside of the front casing.
Also check that the burner is appropriate for the type of gas to burn.
•Make sure that the pipes and fittings used for the gas service are perfectly tight and that there are no gas
leaks.
•Prior to start-up, the central heating pipes should be flushed to remove any residues that could compromise the
operation of the appliance.
•The appliance can be regarded as being electrically safe when it has been connected to an efficient earth system
installed in accordance with the requirements of current safety standards. This fundamental safety requirement must
be checked and verified. In case of doubt, have the electrical system checked by a qualified electrician. The
manufacturer will not be held liable for any damage or injury caused as a result of an ineffective or non-existent earth
system.
•The domestic power supply must be checked by a qualified electrician to ensure that it can support the maximum
power absorption of the appliance, as indicated on the appliance data plate (positioned on the inside of the front
casing). In particular, make sure that the cable ratings are adequate for the power absorbed.
•Do not use adapters; multiple sockets or extension leads to connect the appliance to the mains power supply.
•The appliance must be connected to the mains power supply through an appropriate electrical isolator in accordance
with the current wiring regulations.
•When using an electrical appliance, a few fundamental rules must be observed:
•Do not touch the appliance with damp or wet parts of the body or when barefoot
•Do not pull on the electric wires
•Do not leave the appliance exposed to atmospheric elements (rain, sun, etc,) unless these conditions have been
expressly provided for.
•Do not allow the appliance to be used by children or anyone unfamiliar with its operation.
•The user must not replace the power supply cable.
•If the cable is damaged in any way, switch off the appliance and have the cable replaced by a suitably qualified
electrician.
•When the appliance is no longer required for use, switch off the main power supply, to switch all electrical
components off (circulating pump, burner etc.)
•Radiant Helpline UK 0870 770 0414

GENERAL INFORMATION
TA05A140.A0307 3
1.2 Product conformity
RADIANT BRUCIATORI S.p.A. declares that all its products are manufactured to a high specification and in
compliance with the relevant standards.
All RADIANT boilers are CE certified and possess technical and functional characteristics that comply with the
following standards:
UNI EN 297 for GAS-FIRED CENTRAL HEATING BOILERS TYPE B OF NOMINAL HEAT INPUT ≤70 kW
EN 483 for GAS-FIRED CENTRAL HEATING BOILERS TYPE C OF NOMINAL HEAT INPUT ≤70 kW
UNI EN 677 for GAS-FIRED CENTRAL HEATING BOILERS. SPECIFIC REQUIREMENTS FOR CONDENSING
BOILERS WITH NOMINAL HEAT INPUT ≤70 kW
Gas fired boilers also comply with the following directives:
GAS APPLIANCES DIRECTIVE 90/396 CEE for CE compliance
LOW VOLTAGE DIRECTIVE 73/23 CEE
ELECTROMAGNETIC COMPATIBILITY DIRECTIVE 89/336 CEE
BOILER EFFICIENCY DIRECTIVE 92/42 CEE
The materials used such as copper, brass, stainless steel, etc. form a compact, homogeneous, highly functional
unit that is easy to install and simple to operate. In its simplicity, the wall-mounted appliance is equipped with all the
appropriate accessories required to make it a fully independent boiler capable of satisfying domestic hot water
production and central heating needs. All boilers are fully inspected and are accompanied by a quality certificate,
signed by the inspector, and a guarantee certificate. This manual must be kept in a safe place and must
accompany the boiler at all times.
RADIANT BRUCIATORI S.p.A. will not be held responsible for any misinterpretation of this manual
resulting from the inaccurate translation of same.
RADIANT BRUCIATORI S.p.A. will not be held responsible for the consequences in the case of non-
observance of the instructions contained in this manual or in the case where actions not specifically
described herein are undertaken.
Radiant Bruciatori S.p.A. declare that no substances harmful to health are contained in the appliance or
used during appliance manufacture and have not used or intend to use any of the following substances in
the manufacture of Radiant heating products.
−Asbestos
−Mercury
−CFC's.

TECHNICAL CHARACTERISTCS
TA05A140.A0307 4
2. TECHNICAL CHARACTERISTICS
2.1 Technical data
Models RK 25
CE Certification n° 0694BN3485
Appliance Type C13, C33, C43, C53, C63, C83
Appliance Category II2H3+
Heat Input max kW 25
Heat Input min kW 9
Heat Output max (50/30°) kW 26.67
Efficiency 100% (full load 50/30°) % 106.7
Efficiency 30% (partial load 50/30°) % 106.3
Heat Output max - 80/60°C (Non condensing) kW 24.6
Heat Output min - 80/60°C (Non condensing) kW 8.73
Efficiency 100% (full load 80/60°) % 98.4
Efficiency 30% (partial load 80/60°) % 100.1
GAS DIRECTIVE 92/42/ECC - Efficiency marking stars 4
Sedbuk band A
SAP - Seasonal Efficiency Rating % 90.2
Central Heating circuit
Central Heating water temperature setting (min-max) °C 30-80
Max. heating working temperature °C 80
Expansion vessel capacity litres 8
Max. working pressure (heating) bar 2.5
Min. working pressure (heating) bar 0.3
Dimensions (Boiler casing size)
Width mm 410
Height mm 730
Depth mm 285
Weight (net) kg 46
Hydraulic connections
Central Heating Flow connection Ø 3/4”
Central heating Return connection Ø 3/4”
Gas connection Ø 1/2”
Flue systems
Horizontal-Concentric flue system Ø mm 60/100
Max. Flue length m 5
Twin pipe flue system Ø mm 80/80
Max. Flue length (from terminal to terminal) m 50
Twin pipe flue system Ø mm 60/60
Max. Flue length (from terminal to terminal) m 30
Vertical-Concentric flue system Ø mm 60/100
Max. Flue length m 5
Gas Supply
Natural gas G 20
Inlet pressure mbar 20
Gas consumption m3/h 2.65
Butane G30
Inlet pressure mbar 30
Gas consumption kg/h 1.97
Propane G31
Inlet pressure mbar 37
Gas consumption kg/h 1.94
Electrical specifications
Power supply V/Hz 230/50
Electrical power consumption W 170
Electrical protection IP X4D

TECHNICAL CHARACTERISTCS
TA05A140.A0307 5
110137163
285
132
730
HF
G
HR
49 31 285
730
111.5187111.5
48.5 313 48.5
105
182148
2.2 Dimensions
LEGEND
HR HEATING RETURN Ø3/4”
HF HEATING FLOW Ø3/4”
G GAS Ø1/2”
SC CONDENSATE DRAIN Ø25

TECHNICAL CHARACTERISTCS
TA05A140.A0307 6
2.3 Internal parts of the boiler
LEGEND
1. PRIMARY CONDENSING HEAT EXCHANGER
2. PREMIX BURNER UNIT (GAS MANIFOLD + BURNER)
3. CONDENSATE DRAIN PIPE
4. IONISATION ELECTRODE
5. IGNITION ELECTRODE
6. FAN
7. VENTURI
8. IGNITION TRANSFORMER
9. ELECTRONIC GAS VALVE
10. 3 BAR PRESSURE RELIEF VALVE - HTG CIRCUIT
11. AUTOMATIC AIR VENT VALVE
12. HEATING SAFETY THERMOSTAT
13. HEATING SENSOR
14. PUMP WITH AIR VENT
15. WATER PRESSURE SWITCH
16. FLUE HOOD
17. SAFETY THERMO FUSE
18. EXPANSION VESSEL
19. ROOM SEAL CHAMBER BACK SIDE
20. CONDENSATE TRAP
21. WATER PRESSURE GAUGE
22. AUTOMATIC BY-PASS
23. CONDENSATE DRAIN PIPE
24. SYSTEM DRAIN VALVE
13
24
19
5
15
17
3
2
16
23
9
18
1
12
21
20
7
6
10
14
22
11
8
41
11
9
19
14
12
6
5
4
16
2

TECHNICAL CHARACTERISTCS
TA05A140.A0307 7
2.4 Water circuit
LEGEND
1. PRIMARY CONDENSING HEAT
EXCHANGER
2. PREMIX BURNER UNIT (GAS
MANIFOLD+BURNER)
3. PRIMARY CONDENSING HEAT
EXCHANGER CONDENSATE DRAIN PIPE
4. IONISATION ELECTRODE
5. IGNITION ELECTRODE
6. FAN
7. VENTURI
8. IGNITION TRANSFORMER
9. ELECTRONIC GAS VALVE
10. 3 BAR PRESSURE RELIEF VALVE - HTG
CIRCUIT
11. AUTOMATIC AIR VENT VALVE
12. HEATING SAFETY THERMOSTAT
13. HEATING SENSOR
14. PUMP WITH AIR VENT
15. WATER PRESSURE SWITCH
16. FLUE HOOD
17. SAFETY THERMO FUSE
18. EXPANSION VESSEL
19. ROOM SEAL CHAMBER BACK SIDE
20. CONDENSATE TRAP
21. WATER PRESSURE GAUGE
22. AUTOMATIC BY-PASS
23. CONDENSATE DRAIN PIPE
24. SYSTEM DRAIN VALVE
LEGEND
HR HEATING RETURN Ø3/4”
HF HEATING FLOW Ø3/4”
G GAS Ø1/2”
SC CONDENSATE DRAIN Ø25
5
16
2
3
17
18
19
23
GHFHR
SC
4
22
12
1
13
21
14
10
11 20
9
6
8
15
7

TECHNICAL CHARACTERISTCS
TA05A140.A0307 8
2.5 Circulation pump head/flow graph
I
II
I
II
III
14001200 1600
70
50
60
40
1000
800400 600
30
10
20
0
0200
III
Appliance Loss
Available head at minimum speed
Available head at second speed
Available head at maximum speed Flow l/h
Head (kPa)

TECHNICAL CHARACTERISTCS
TA05A140.A0307 9
2.6 DIGITECH®printed circuit board – SM 20019
Technical characteristics
Ad
j
ustments possible b
y
service personnel onl
y
•Standard (30/80°C) / reduced (25-40°C) central heating temperature
•Water hammer prevention function
•Central Heating timer - (adjustable from 0 to 7,5 minutes)
•Central Heating pump overrun timer
•Domestic Hot Water pump overrun timer (not applicable)
•Minimum Gas pressure setting
•Maximum Heating Load
User settings
•On/Off
•Heating Temperature setting (30-80°C) – (25-40°C)
•D.H.W. temperature setting (35-60°C)
•Summer only mode / Winter only mode / Summer + Winter mode selection
Operation/Functions display
•Lock-Out
•Normal Water pressure
•Water deficiency indicator
•Temperature display
ÎWhen the boiler is switched off at the switch on the control panel, the word OFF appears on the
display. The central heating frost protection system, nevertheless, remain enabled. If the boiler was
previously on, it is switched off and the post-ventilation, pump overrun and circulation pump inactivity
protection functions are enabled.
ÎThe remote control, where fitted, remains active and illuminated.
2.7 Control panel
LEGEND
1. ON/OFF SWITCH
2. HEATING TEMPERATURE CONTROL KNOB
3. D.H.W TEMPERATURE CONTROL KNOB.
(not applicable)
4. D.H.W TEMPERATURE BUTTON. KEEP
PRESSED FOR 5 SECONDS TO DISPLAY
OUTSIDE TEMPERATURE (ONLY WITH
OPTIONAL OUTDOOR SENSOR)
5. SERVICE BUTTON.
6. SUMMER, WINTER OR SUMMER/WINTER
MODE SELECTION BUTTON.
7. TERMINAL BOARD FOR EXTERNAL
WIRING.
8. TEMPERATURE, ERROR CODE AND
OPERATING STATUS DISPLAY 6754321
8

INSTALLATION INSTRUCTIONS
TA05A140.A0307 10
3. INSTALLATION (authorised personnel)
3.1 Reference standard
In GB, the installation must be carried out by a CORGI Registered Installer. To check for authorised
qualified engineers please contact CORGI 01256-372400. It must be carried out in accordance with the
relevant requirements of the:
- Gas Safety Regulations;
- The appropriate Building Regulations either The Building Regulation, 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 shoud be made to the relevant British Standards
Code of Practice.
In GB, the following Codes of Practice apply:
BS 5440:Part1 – Flues
BS 5440:Part2 – Air Supply
BS 5446 Installation of hot water supplies for domestic purposes (1st, 2nd and 3rd family gases)
BS 5449 Forced circulation hot water systems
BS 6700 Installation of cold water supplies for domestic purposes (1st, 2nd and 3rd family gases)
BS 6798 Installation of gas-fired hot water boilers
BS 6891 Gas Installation
BS 7074 Expansion Vessels and ancillary equipment for sealed water systems
BS 7593 Treatment of water in domestic hot water central heating systems
BS 7671 IEE wiring regulations.
This appliance meets the requirements of:
- UNI EN 677 for GAS-FIRED CENTRAL HEATING BOILERS. SPECIFIC REQUIREMENTS FOR CONDENSING
BOILERS WITH NOMINAL HEAT INPUT ≤70 kW
- IPX4D rating for electrical appliances.
- EMC DIRECTIVE 89/336 CEE
- LVD DIRECTIVE 73/23 CEE
- BOILER EFFICIENCY DIRECTIVE 92/42 CEE
Failure to install a gas appliance correctly and in accordance with the above norms could lead to prosecution. It is
in the interest of the installer and safety that the law is complied with.
The manufacturers instructions form an integral part of the installation and should be left with the appliance but do
not over ride in anyway statutory obligations.

INSTALLATION INSTRUCTIONS
TA05A140.A0307 11
B
C
A
3.2 Boiler room – Installation requirements
Please refer to local and national standards in force in the Country of destination of the product. In particular the
manufacturer recommends:
The presence of threaded connections on the gas line, require that the room in which the appliance is
installed is ventilated by means of air intakes.
Boilers can be installed outdoor, in a partially protected place in conformity with Local Regulation and
if the outside minimum temperature is not lower than –10°C, ensuring gas and electric mains to the
appliance. The manufacturer is not responsible for external installations where the outside
temperature is lower than – 10°C or not in conformity with above instructions.
3.3 Unpacking
■The materials (cardboard) used for packing the appliance are fully recyclable.
■It is recommended that the packing material is only removed prior to installing the boiler. The
manufacturer will not be held responsible for damage caused by incorrect storage of the product.
■Packing materials (plastic bags, polystyrene, nails, etc.) must not be left within reach of children, in that
these items represent a potential hazard.
A. Place the packed
appliance on the floor (see fig.
1) making sure that the "up”
arrow is facing down. Remove
the staples and open out the
four flaps of the box.
B. Rotate the boiler 90° while
manually supporting it from
underneath
C. Lift the box and remove the
protections. Lift the boiler by
grasping the rear part and
proceed with the installation.
STORAGE & HANDLING
Please note that prior to
installation the Radiant boilers
should be stored in the
horizontal position with no
more than three boilers to a
stack;
Ensure that the boilers are
stored in dry conditions and be
aware that the carton is a tow-
man lift;
Fig. 1

INSTALLATION INSTRUCTIONS
TA05A140.A0307 12
MINIMUM DISTANCES IN mm
H
A
XLY
Model X Y L H
10004106060
B
AB
200 300
RK 25
3.4 Installing the boiler
■The appliance must be installed
exclusively on a flat vertical solid
wall capable of supporting its
weight.
■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 3.4.1
“Compartment Ventilation”).
■If the boiler is sited in an unheated
enclosure then it is recommended to
leave the power on to give frost
protection (frost protection is active
even with On/Off switch in Off
position).
■If the boiler is installed 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 order to allow access to the interior of
the boiler for maintenance purposes, it is
important that the necessary clearances
indicated in figure 1 are respected. To
make the installation easier, the boiler is
supplied with a template to enable the
pipe connections to be positioned prior to
fixing the appliance to the wall.
To install the boiler, proceed as follows
(see fig. 2):
a. Use a spirit level (of not less than 25
mm long) to mark a horizontal line on
the wall where the boiler is to be
fitted.
b. Position the top of the template along
the line drawn with the level,
respecting the distances indicated.
Then mark the centres of the
positions of the two wall-plugs or
anchors. Finally, mark the positions of the water and gas pipes.
c. Remove the template and install the domestic hot and cold water pipes, the gas supply pipe and the central
heating pipes using the fittings supplied with the boiler.
Fix the boiler to the wall using the wall plugs or bracket and connect the pipes.
3.4.1 Compartment Ventilation
Where the appliance is installed in a compartment, no air vents are required.
BS 5440:Part 2 refers to room sealed appliances installed in compartments. The appliance will run sufficiently cool
without ventilation.
Fig. 1
Fig. 2

INSTALLATION INSTRUCTIONS
TA05A140.A0307 13
14849 182 31
HR G HF
105
HF
G
HR
Ø 22 mm
Ø 15 mm
Ø 22 mm
3.5 Water connections
In order to safeguard the heat
exchanger and circulation pump,
especially in case of boiler replacement,
it is recommended that the system is
hot-flushed to remove any impurities
(especially oil and grease) from the
pipes and radiators.
Make sure that the domestic water and
central heating pipes are not used to
earth the electrical system. The pipes
are totally unsuitable for this purpose.
Isolation Valves must be installed on
the heating and D.H.W circuits. This will
facilitate all maintenance and service
operations where the boiler needs to be
drained.
■To prevent vibration and noise coming from
the system, do not use pipes of reduced
diameter, short radius elbows or severe
reductions in the cross sections of the
water passages.
■In order to guarantee the reliability of the
boiler and prevent permanent damage in
areas with high water inlet pressure too,
a 2.5 bar pressure reducing valve should
be fitted.
■To facilitate the installation, the boiler is
supplied with an hydraulic connection kit
(see fig.2).
Central heating circuit
In order to prevent scaling or deposits in the
primary heat exchanger, the mains supply water
to the heating circuit must be treated according to
the requirements of local standards.
This treatment is indispensable in the case
where the circuit is frequently topped-up or when
the system is often either partially or fully drained.
The outlet connection of the boiler safety
valve must be connected to a discharge
trap. The manufacturer will not be held
responsible for flooding caused by the operation
of the safety valve in the case of system
overpressure.
Condensate Drain
The condensate drain flexible pipe supplied with the boiler (conforming to UNI EN 677 standard) must be
connected to a proper condensate trap. The condensate discharge into the drainage system is allowed providing a
condensate trap (siphon) is installed.
Any condensate discharge pipe work external to the building (or in an unheated part of it) must be insulated to
protect against frost. Before switching the boiler On, check the correct condensate discharge.
LEGEND
HR HEATING RETURN Ø3/4”
HF HEATING FLOW Ø3/4”
G GAS Ø1/2”
Fig. 2
Fig. 1

INSTALLATION INSTRUCTIONS
TA05A140.A0307 14
3.6 Central heating circuit
The boiler is designed for use in a sealed central heating system in accordance with the requirements of BS 5449 and BS 6798.
The system should be designed to operate with flow temperatures of up to 82°C. When designing the system, the pump head,
expansion vessel size, mean radiator temperature, etc. must all be taken into account. Refer to the pump performance table for
guidelines.
System volume -The expansion vessel incorporated into the boiler is suitable for a sealed heating system
The boiler is supplied with the following components built in:-
Pressure relief valve -complying with BS 6759 and set to operate at 3 bars. The outlet connection of the boiler safety valve
must terminate to atmosphere in accordance with current regulations. The manufacturer will not be held responsible for
flooding caused by the operation of the safety valve in the case of system overpressure..
Pressure gauge -To indicates the system pressure to be maintained.
Expansion vessel – Conforming to BS 7074:1 for GB,
By-pass -The boiler incorporates a by-pass, however where all radiators are fitted with thermostatic radiator valves it is
recommended an automatic system by-pass is fitted.
Additional expansion
vessel (if required)
Double check valve assy
Temperature/pressure
relief valve
Boiler
Automatic air vent
Heating return
System
drain tap
Note: A drain tap should be installed at the lowest point of the
heating circuit and beneath the appliance
Note: If required, an automatic
by-pass is preferred
Radiator
valve
Filling point
DHW outlet
Pressure reducing
valve (supplied)
Mains water
inlet
Static head of system
Make up vessel
Heating by-pass
(if required)
Lockshield valve
Filling the central heating system – figs. 2-3
The system design pressure (cold) should be set to 1.5 bar. This pressure is equivalent to a static head of 15.4 metres of
water.
Provision should be made to replace water lost from the system. This can be by manual or automatic means. as shown in Figs.
2 and 3. The position for connecting an automatic make-up vessel is indicated in Fig. 1. A double check valve assembly must
be used. as shown in Fig. 3.
Filling of the system must be carried out in a manner approved by the local Water Undertaking (GB: Guidance G24.2 and
Recommendation R24.2 of the Water Regulation Guide). Where allowed the system may be filled via a temporary connection
as shown in Fig. 2. After filling, always disconnect the flexible hose of the filling loop.
All fittings used in the system must be able to withstand pressures up to 3 bar.
Drain taps (to BS 2879) must be used to allow the system to be completely drained.
Double
check valve
assembly
Test
cock
Feed cistern to be
located above highest
point in the system
Overflow
Heating
circuit
return
Test
cock
Double
check valve
assembly
Stop
valve
M
a
i
ns water
supply
Mains
water
supply
Stop
valve
Filling loop
temporarily
connected
Hose
unions
Heating
circuit
return
In order to prevent scaling or deposits in the primary heat exchanger, the mains supply water to the heating circuit
must be treated according to the requirements of standard.
This treatment is indispensable in the case where the circuit is frequently topped-up or when the system is often either partially
or fully drained.
Fig. 1
Fig. 2 Fig. 3

INSTALLATION INSTRUCTIONS
TA05A140.A0307 15
3.7 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.
I. The condensate outlet terminates in 22 mm nut and
seal for the connection of 22 mm (3/4 in) 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 H I 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 pipe work is NOT suitable for use in
condensate discharge systems.
5. The pipe should be a minimum of 21.5 mm 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 pipe work 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 alI cases discharge pipe must be installed to aid
disposal of the condensate. T o 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 soak away
450mm min
Holes in the soak-away must
face away from the building
500mm min
External termination to a purpose made soak-away
External termination to a drain or gully
Pipe must terminate above
water level but below
surrounding surface
50mmpermetreofpiperun
2.5°Minimumfall
50mmpermetreofpiperun
2.5°Minimumfall
Boiler
Pipe must terminate above
water level but below
surrounding surface
50mmpermetreofpiperun
2.5°Minimumfall
External termination via internal discharge
branch e.g. sink waste - downstream
Sink
2.5°Minimumfall
50mmpermetreofpiperun
Termination to an internal soil and vent pipe
Boiler
Boiler
Boiler

INSTALLATION INSTRUCTIONS
TA05A140.A0307 16
3.8 Gas Connection
The connection to the gas supply must be carried out by professionally qualified personnel in
accordance with relevant standards:
In GB this is BS 6891.
When connecting the boiler to the gas supply pipe, only use appropriate washers and gas fittings.
The use of hemp, Teflon tape and similar materials is not allowed.
Before installing the boiler, check the following:
■The pipe work must have a section appropriate for the flow rates requested and the pipe lengths installed, and
must be fitted with all the safety and control devices provided for by current standards.
■The gas supply line must be a minimum of a 22 mm diameter pipe with an uninterrupted supply from meter to
boiler and comply with current standards and regulations.
■Check the internal and external seals of the gas supply system.
■A gas shut-off valve must be installed upstream of the appliance
■The gas pipe work must have and bigger or equal section to the one of the boiler.
■Before starting up the boiler, make sure that the type of gas corresponds to that for which the appliance has
been set-up (see gas type label inside the boiler).
■The gas supply pressure must be between the values reported on the rating plate (see gas type label inside the
boiler).
■Prior to installation, it is good practice to ensure that there are no machining residues on the gas supply pipe.
■Conversion of the appliance from natural gas to LPG or vice versa must be carried out by qualified personnel ;