Ferroli SIGMA, Sigma 20 - 40 GC N° 41-267-17, Sigma 40 - 60 GC N° 41-267-18, Sigma 20 - 40 GC, Sigma 40 - 60 GC Installation And Servicing Instructions
SIGMA
INSTALLATION AND
SERVICING INSTRUCTIONS
Wall Mounted Cast Iron,
Gas Fired Boiler for Central Heating
Fan Assisted, Room Sealed,
Electronic Flame Ignition and Control
cod. 3543556/0 - 10/2001
Sigma 20 - 40 GC N° 41-267-17
Sigma 40 - 60 GC N° 41-267-18
2
Sigma
INDEX PAGE
1. TECHNICAL CHARACTERISTICS .......................................................................................3
2. INSTALLATION ...................................................................................................................6
3. COMMISSIONING AND TESTING...................................................................................22
4. ADJUSTMENT ..................................................................................................................23
5. GAS CONVERSION ..........................................................................................................24
6. MAINTENANCE AND CLEANING ..................................................................................25
7. REPLACEMENT OF PARTS...............................................................................................27
8. FAULT FINDING................................................................................................................30
9. USER INSTRUCTIONS ......................................................................................................33
C.O.S.H.H.
Materials used in the manufacture of this appliance are non hazardous and no special precautions are
required when servicing.
IMPORTANT
Your "benchmark" Installation, Commissioning and Service Record Log Book will be enclosed in your
customer information pack. This record must be completed and left with the end user.
Ferroli is a member of the Benchmark initiative and fully supports the aims of the programme. Benchmark
has been introduced to improve the standards of installation and commissioning of central heating
systems in the UK and to encourage the regular servicing of all central heating systems to ensure
safety and effi ciency.
CE MARK
CE mark documents that the Ferroli gas appliances comply with the requirement contained in European
directives applicable to them.
In particular, the appliances comply with the following CEE directives and the technical specifi cations
provided from them:
• Gas appliances directive 90/396
• Effi ciencies directive 92/42
• Low tension directive 73/23 (modifi ed from the 93/68)
• Electromagnetic compatibility directive 89/396 (modifi ed from the 93/68)
3
Sigma
Fig. 1
Key
1 - Ø 22 mm fl ow outlet
2 - Ø 22 mm return inlet
3 - Ø 15 gas inlet
4 - Rear air inlet/fl ue outlet
5 - Top air inlet/Flue outlet
25
A
25
B 85
147
15
50
120 50
D
C
132
50
200
2
1
Front view
Right side view
220
Top view
3
4
600
620
200
78
5
Model
Sigma 20-40
Sigma 40-60
A
mm
320
400
B
mm
53
133
C
mm
35
30
D
mm
60
55
1. TECHNICAL CHARACTERISTICS
1.01 Introduction
The Sigma is defi ned as a “room sealed” boiler, all air required for combustion is taken from outside the room in which it
is installed. It is a new high performance gas fi red heat generator, which is designed to provide indirect hot water and/or
central heating. The cast iron heat exchanger is suitable for use on fully pumped hot water/central heating systems,
which may be sealed or open vented. A special feature of this boiler is its built-in electronic fl ame ignition and control
unit making burner operation completely automatic and safe.
The main components are as follows:
Cast iron heat exchanger specifi cally shaped for high effi ciency.
Ceramic fi bre insulated combustion chamber
One stainless steel bladed burner specifi cally designed for this boiler.
Fan for discharge of combustion products and intake of combustion air.
Differentia l air pressure switch. For safety reasons, this ensures the burner ignites only when the fan is
functioning correctly.
Hermetically sealed compartment made from corrosion-resistant steel enclosing the above components.
Combination gas safety valve, complete with pressure stabiliser.
Central heating fl ow temperature adjustment thermostat.
Overheat safety thermostat.
Electronic control unit for automatic fl ame ignition and control.
Central heating fl ow temperature sensor.
1.02 Dimension
4
Sigma
Protection
level
IP 40
IP 40
Boiler
water
contents
1,3
1,6
litres
Weight
30
35
kg
Model
15
15
Gas inlet
3
Ø
Return
2
Ø
22
22
22
22
Flow
1
Ø
3
3
bar
Max. working
pressure
C.H.circuit
Connections
Gas valve
Ø 1/2”
Honeywell
VK 4105 A
VK 4105 A
Sigma 20/40
Sigma 40/60
Model
Sigma 20/40
Sigma 40/60
G31-LPG
mbar
37
37
20
20
G20-NG
mbar
Burner gas pressures
G31-LPG
Nominal
mbar
36
36
Minimum
mbar
9,0
16,0
Nominal
mbar
14,0
15,3
Minimum
mbar
3,1
6,4
Gas supply pressures
G20-NG
11,7
17,6
MaxkWMin
kW
5,5
11,4
13,0
19,5
MaxkWMin
kW
6,1
12,7
14,4
21,7
MaxkWMin
kW
6,8
14,1
Model
Sigma 20/40
Sigma 40/60
Heat
output
Heat
input
(net)
Heat
input
(gross)
G31-LPG
Ø
1,8
2,30
3,0
3,60
G20-NG
Ø
1,37
2,06
Max
0,64
1,34
Min
1,02
1,53
Max
0,48
0,99
Min
G20 m3/h-NG G31 kg/h-LPG
Injectors
(mm)
Gas flow rates
N.B. • Maximum working temperature 82°C, adjustable between 60°C and 82°C.
1.03 Technical data
5
Sigma
1.04 General Layout and Main Components
Fig. 2
19
27
132
1 16 1
34
11
86
121
68
63
24
83
44
22 21 7
5
151
49
43
28
90
1091
Air in
C.H.
in
C.H.
out
Flue out
Gas in
1.05 Boiler water fl ow diagram
Fig. 3
Key
1 Fixing points
5 Room sealed compartment
7 Inlet gas-cock
10 Central heating fl ow outlet
11 Central heating return inlet
16 Fan
19 Combustion chamber
21 Gas injector
22 Burner
24 Spark and sensor electrode
27 Cast iron heat exchanger
28 Flue collector from heat exchanger
34 Central heating fl ow
temperature sensor
43 Air pressure switch
44 Gas valve
49 Safety overheat thermostat
63 Central heating temperature setting
68 Control box with P. C . B .
83 Full sequence automatic control
86 Automatic control reset switch
90 Flue outlet pressure test point
91 Air pressure test point
121 Boiler shut-down warning
132 Flue gas defl ector
151 Drain tap
.1 .2
20
30
40
50
60
70
80
90
200
300
.3 .4 .5 .6 .7 .8 .9 2 31
100
10
Water flow rate (m
3
/h)
Pressure drop mm wg
2
1
1 = Sigma 20-40
2 = Sigma 40-60
Pressure loss diagram
6
Sigma
2. INSTALLATION
2.01 Important notices
Assembly, installation, fi rst start up and maintenance must be carried out by competent persons only, in accordance
with all current technical regulations and directives.
Gas Safety (Installation & Use) Regulations: 1996
In the interest of safety, it is the law that all gas appliances are installed by a competent person in accordance with the
above Regulations, Building Regulations/Building Standards Scotland, Codes of Practice, current I.E.E. Regulations and
the byelaws of the Local Water Undertaking. Failure to comply with the Regulations may lead to prosecution; it is your
responsibility to ensure that the law is complied with.
This appliance must be installed strictly in accordance with these instructions and regulations:
The Gas Safety Regulations (Installations & Use) 1996.
The Local Building Regulations.
The Building Regulations.
The Buildings Standards (Scotland - Consolidated) Regulations.
British Standards Codes of Practice:
B.S. 5440 Part 1 2000 Flues
B.S. 5440 Part 2 1989 Air supply
B.S. 5449 1990 FORCED CIRCULATION HOT WATER SYSTEMS
B.S. 6798 1987 INSTALLATION OF GAS FIRED HOT WATER BOILERS
B.S. 6891 1989 GAS INSTALLATIONS
B.S. 7671 1992 IEE WIRING REGULATIONS
B.S. 4814 1990 SPECIFICATION FOR EXPANSION VESSELS
B.S. 5482 1994 INSTALLATION OF LPG
B.S. 7593 1992 TREATMENT OF WATER IN DOMESTIC HOT WATER CENTRAL HEATING SYSTEMS
Model Water Bye Laws
For Northern Ireland the rules in force apply
N.B. For Northern Ireland the rules in force apply.
Important - If the boiler is to be fi tted in a timber framed building it should be fi tted in accordance with
the institute of gas engineers publication IGE/UP/1. If in doubt advice should be sought from the Local Gas
Region of British Gas Plc.
2.01.01 Location of Boiler
The installation of the Sigma must be on a suitable non-combustible load bearing wall which will provide an adequate fi xing
for the boiler mounting bracket assembly. The location should be in an area where the water pipes will not be subjected
to frost conditions. In siting the boiler the following limitations must be observed:
The boiler may be installed in any room or internal space, although particular attention is drawn to the requirements of the
current I.E.E. wiring regulations and in Scotland the electrical provisions of the building regulations applicable in Scotland,
with respect to the installation of the boiler in a room or internal space containing a bath or shower.
Where a room sealed appliance is installed in a room containing a bath or shower any electrical switch or
appliance control utilising mains electricity must be situated so that it cannot be touched by a person using
the bath or shower.
2.01.02 Air Supply
The room or compartment in which the boiler is installed does not require a purpose provided vent when using
the standard concentric fl ue.
2.01.03 Flue System
The boiler allows the fl ue outlet to be taken from the rear of the boiler, from either side or vertically.
It is absolutely essential, to ensure that products of combustion discharging from the terminal cannot re-enter
the building, or enter any adjacent building, through ventilations, windows, doors, natural air infi ltration or
forced ventilation/air conditioning.
7
Sigma
Fig. 4a
Gas
Pump
Expansion
vessel
Cold water
1
3
2
Filling point
Note: A bypass must be fi tted as far
as possible from the boiler if
thermostatic radiator valves
are fi tted thoughout.
2.01.04 Gas Supply
If necessary the local Gas supplier should be consulted, at the installation planning stage, in order to establish
the availability of an adequate supply of gas.
An existing service pipe must not be used without prior consultation with the Local Gas supplier.
A gas meter can only be connected by the Local Gas supplier, or by a Local Gas suppliers Contractor.
Installation pipes should be fi tted in accordance with BS6891-1988.
Appliance inlet working pressure must be 20mbar MINIMUM (Natural gas - G20) or 37 mbar MINIMUM (LPG - G31).
Pipework from the meter to the combination boiler must be of an adequate size.
Do not use pipes of a smaller size than the combination boiler inlet gascock connection.
The complete installation must be tested for gas soundness and purged as described in BS6981-1988. All pipework
must be adequately supported.
2.02 Water System (sealed systems)
Central heating
Detailed recommendations are given in BS6798, BS5449, BS6700 and CP342 Part 2. Pipework not forming part of the
useful heating suface should be insulated to prevent any heat losses or possible freezing (i.e. in roof spaces or ventilated
underfl oor spaces). Drain taps should be positioned at the lowest point of the system in accessible locations to permit
the whole system to be drained down. The drain taps should be in accordance with BS2879. Copper tubing to BS2871,
Part 1 is recommended for water carrying pipework. Pipework in horizontal runs should have a gradient where possible
to facilitate the removal of air. Ensure that the boiler heat exchanger is not a natural point for air collection. A
typical sealed heating system illustrated in fi g. 4.
Typical sealed fully pumped heating system
8
Sigma
To DHW taps
Static Head
min. 1 m
max. 150 mm
Isolating valve
Drain
Flow
Return
Open
Vent
Open
Vent
Motorised valve
28 mm
gravity DHW
Isolating valve
CH Pump
By-pass
Motorised valve
22 mm CH
Radiator Radiator
28 mm
28 mm
15 mm
22 mm
Schematic layout for gravity DHW and pumped CH for Sigma Boiler
Fig. 4b
9
Sigma
Important - If thermostatic radiator valves are fi tted throughout a bypass must be fi tted to ensure a minimum fl ow rate
through the boiler of 6 l/min. The bypass should be fi tted as far as possible from the boiler.
2.02.01 Safety valve
A safety valve complying with the requirements of BS 6750 Part 1 must be fi tted close to the boiler on the fl ow pipe by
means of a horizontal or vertically upward connection with no intervening valve or restrictions and should be positioned
to facilitate testing. The valve should be pre-set and nonadjustable to operate at a pressure of 3 bar (45 Ibf/in2). It must be
arranged to discharge any water or steam through a pipe to a safe outlet position.
2.02.02 Pressure gauge
A pressure gauge of minimum range 0-4 bar (0-60 Ibf/in2) with a fi ll pressure indicator must be fi tted to the system,
preferably at the same point as the expansion vessel in an easily visible position.
2.02.03 Venting
A method of venting the system during fi lling and commissioning must be provided by fi tting automatic air
vents or by venting manually.
2.02.04 Expansion vessel
In a sealed system an expansion vessel complying with the requirements of BS 4814 must be fi tted to the system
by means of a connection close to the inlet side of the circulating pump in accordance with the manufacturers
instructions, the connecting pipe being unrestricted and not less than 15 mm (1/2 in) nominal size. The volume
of the vessel should be suitable for the system water content and the nitrogen or air charge pressure should
not be less than the system static head.
Further details of sealed system design can be obtained from BS 5449: Part 1 and the British Gas publication entitled
Specifi cations for Domestic Wet Central Heating Systems.
2.02.05 Water treatment
If water treatment is used ferroli limited recommend only the
use of Fernox or Sentinel water treatment products, which must
be used in accordance with the manufacturers instructions. For
further information contact:
Fernox Manufacturing Co. LTD. Sentinel Division
Tandern house, Marlowe Way Betz Dearborn LTD
Croydon, surrey, CRO 4YS Widnes, Cheshire WA8 8ND
Te l: 0870 5601 5000 Te l : 0151 424 5351
Note - If the boiler is installed in an existing system any
unsuitable additives must be removed by thorough cleansing.
All systems should be cleansed according to B.S. 7593.
Note - In hard water areas treatment to prevent lime scale
may be necessary.
Note - It is important that the correct concentration of the
water treatment product is maintained in accordance with the manufacturers instructions.
2.03 Gas connection
Gas connection must be carried out using a rigid pipe.
The fl ow at the gas meter should be suffi cient for the simultaneous use of all appliances connected to it. Connect
the gas supply to the boiler according to current regulations. The diameter of the gas cock leaving the boiler is not
the determining factor in choosing the diameter of the pipe between the appliance and the meter. This must be
selected in relation to length and pressure drop.
The whole of the gas installation including the meter should be inspected and tested for soundness and purged
in accordance with BS6891-1988.
VESSEL CHARGE
PRESSURE (bar)
INITIAL SYSTEM
PRESSURE (bar)
TOTAL WATER
CONTENT of SYSTEM
Litres
25
50
75
100
125
150
175
200
0.33
For syst. volumes other than
those given above, mult. the syst.
volume by the factor across.
0.5 1.0
EXPANSION VESSEL VOLUME (litres)
8.3
16.5
24.8
33.1
41.3
49.6
57.9
66.2
1.5
2.0
10.3
20.6
30.9
41.2
51.5
61.8
72.1
82.4
0.412
2.0
4.7
9.5
14.2
19.0
23.7
28.5
33.2
38.0
0.190
1.5
13.7
27.5
41.3
55.1
68.9
82.6
96.4
110.2
0.551
2.0
6.5
12.9
19.4
25.9
32.4
38.8
45.3
51.8
0.259
1.5
3.5
7.0
10.5
14.0
17.5
21.0
24.5
28.0
0.140
1.0
Sizing of expansion vessels:
10
Sigma
105 min
205 min
254,5
620
Ø*
A
Boiler
mounting
plate
810 min
147
5 min
100
200 min
200
200 min 610
100
Fig. 5
Model
Sigma 20-40
Sigma 40-60
A
320
400
B
60 min.
140 min.
C
120
200
2.04 Wall Mounting
2.04.01 Drilling Template
80
111
Ø118
WARNING:
C.H. connection
on this side
A
135
B
230 min.620
200 min.
C
80
91
Ø90
A
135B
WARNING:
C.H. connection
on this side
200 min.
620
C
Ø90
350 min.
165 min.
Minimum clearances and drilling template for standard
rear fl ue.
Fig. 6a Fig. 6b
Drilling template for orizontal concentric fl ue. Drilling template for two pipe system with orizontal
air inlet.
11
Sigma
2.04.02 Wall mounting instructions for Rear Flue Application
1
Select suitable mounting position for
boiler. Refer to fi g. 6 for dimensions and
minimum clearance. Using the template
or mounting plate mark fl ue outlet and
boiler mounting points.
Fig. 7
Drill four 10 mm holes 70 mm deep to
accept the wall plug. Using a core drill
cut hole for the fl ue.
Drill cut a 118 mm diameter hole if it
is possible insert the fl ue-pipe from
outside of the room; drill cut a 127 mm
diameter hole if to insert the fl ue-pipe
from inside of the room.
2
Fig. 8
Insert the plastic plugs.
3
Fig. 9
5a 5b
Ø 118
Fig. 11a Fig. 11b
4a 4b
Ø 127
Fig. 10a Fig. 10b
Insert fl ue-pipe from inside of the room (core drill 127 mm hole)...
... or insert fl ue-pipe from outside of the room (core drill 118 mm hole).
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