Ferroli Sigma 30 FF 41-267-07 User guide

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. -----------/- - 10/99 Appr. Nr. B 98.06 A - 0461 AT 0344
G.C. NO:
Sigma 30 FF 41 - 267 - 07
Sigma 40 FF 41 - 267 - 08
Sigma 50 FF 41 - 267 - 09
Sigma 60 FF 41 - 267 - 10

INDEX PAGE
1. TECHNICAL CARACTERISTICS ........................................................................................ 3
2. INSTALLATION .................................................................................................................. 6
3. COMMISSIONING AND TESTING ................................................................................. 19
4. ADJUSTMENT ................................................................................................................. 20
5. GAS CONVERSION ......................................................................................................... 21
6. MAINTENANCE AND CLEANING ................................................................................. 22
7. REPLACEMENT OF PARTS ............................................................................................. 24
8. FAULT FINDING .............................................................................................................. 27
9. USER INSTRUCTIONS ..................................................................................................... 30
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 efficiency.
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 specifications provided
from them:
• Gas appliances directive 90/396
• Efficiencies directive 92/42
• Low tension directive 73/23 (modified from the 93/68)
• Electromagnetic compatibility directive 89/396 (modified from the 93/68)
Year 2000 Compliance Declaration
We will guarantee that this products is altogether suitable for the data change in the Year 2000 (boiler has no
dependence from date change) and that no disruptions will occur which is caused by this product.

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Sigma
Fig. 1
Key
1 - Ø 22 mm flow outlet
2 - Ø 22 mm return inlet
3 - Ø 15 gas inlet
4 - Rear air inlet/flue 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 30-40
Sigma 50-60
A
mm
320
400
B
mm
53
133
C
mm
35
30
D
mm
60
55
1. TECHNICAL CARACTERISTICS
1.01 Introduction
The Sigma is defined 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 fired 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 seal or open vented. A special feature of this boiler is its built-in electronic flame ignition and control unit making
burner operation completely automatic and safe.
The main components are as follows:
Cast iron heat exchanger specifically shaped for high efficiency.
Ceramic fibre insulated combustion chamber
One stainless steel bladed burner specifically designed for this boiler.
Fan for discharge of combustion products and intake of combustion air.
Differential 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 flow temperature adjustment thermostat.
Overheat safety thermostat.
Electronic control unit for automatic flame ignition and control.
Central heating flow temperature sensor.
1.02 Dimension

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Sigma
Protection
level
IP 40
IP 40
IP 40
IP 40
Boiler
water
contents
1,3
1,3
1,6
1,6
litres
Weight
30
30
35
35
kg
Model
15
15
15
15
Gas inlet
3
Ø
Return
2
Ø
22
22
22
22
22
22
22
22
Flow
1
Ø
3
3
3
3
bar
Max. working
pressure
C.H.circuit
Connections Gas valve
Ø 1/2”
Honeywell
VK 4105 A
VK 4105 A
VK 4105 A
VK 4105 A
Sigma 30
Sigma 40
Sigma 50
Sigma 60
Model
Sigma 30
Sigma 40
Sigma 50
Sigma 60
G31-LPG
mbar
37
37
37
37
20
20
20
20
G20-NG
mbar
Burner gas pressures
G31-LPG
Nominal
mbar
36
36
36
36
Minimum
mbar
14,0
19,0
23,6
25,0
Nominal
mbar
15,3
14,0
15,3
15,3
Minimum
mbar
6,2
7,3
9,3
10,7
Gas supply pressures
G20-NG
8,8
11,7
14,7
17,6
Max
kW Min kW
5,5
8,5
11,4
14,4
9,8
13,0
16,3
19,5
Max
kW Min kW
6,1
9,4
12,7
16,0
10,9
14,4
18,1
21,7
Max
kW Min kW
6,8
10,5
14,1
17,8
Model
Sigma 30
Sigma 40
Sigma 50
Sigma 60
Heat
output
Heat
input
(net)
Heat
input
(gross)
G31-LPG
Ø
1,6
1,8
2,10
2,30
2,6
3,0
3,30
3,60
G20-NG
Ø
1,03
1,37
1,72
2,06
Max
0,64
0,99
1,34
1,69
Min
0,77
1,02
1,28
1,53
Max
0,48
0,74
0,99
1,25
Min
G20 m
3
/h-NG G31 kg/h-LPG
Injectors
(mm)
Gas flow rates
N.B. • Maximum working temperature 100°C, adjustable between 60°C and 82°C.
1.03 Technical data

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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 flow diagram
Fig. 3
Key
1Fixing points
5Room sealed compartment
7Inlet gas-cock
10 Central heating flow 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 flow
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 deflector
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 30-40
2= Sigma 50-60
Pressure loss diagram

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Sigma
2. INSTALLATION
2.01 Important notices
Assembly, installation, first 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 Flues
B.S. 5440 PART 2 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 fitted in a timber framed building it should be fitted 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 fixing
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 flue.
2.01.03 Flue System
The boiler allows the flue outlet to be taken from the rear of the boiler, from either side or vertically.
A standard flue length of 0.75 metres is provided. Alternative lengths of two or three metres can be supplied (equivalent
to wall thicknesses of up to 565, 1815 and 2815mm for rear flues, deduct 91mm plus distance from side wall for side outlet
flues). 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 infiltration or forced ventilation/
air conditioning.

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Sigma
Fig. 4
Gas
Pump
Expansion
vessel
Cold water
1
3
2
Filling point
Note: A bypass must be fitted as far
as possible from the boiler if
thermostaticradiatorvalvesare
fitted 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 fitted 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
underfloor 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 fig. 4.
Typical sealed fully pumped heating system

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Sigma
Key
1 - Filling point C.H.
2 - Temporary connection
3 - Cold water supply
Fig. 5
Important - If thermostatic radiator valves are fitted throughout a bypass must be fitted to ensure a minimum flow rate
through the boiler of 6 l/min. The bypass should be fitted as far as possible from the boiler.
2.02.01 Make Up Water
Provision must be made for replacing water lost from the
sealed system. Reference should be made to BS6798, for
methods of filling and making up sealed systems. There must
be no direct connection between the boiler's central heating
system and the mains water supply. The use of mains water to
charge and pressurise the system directly, is conditional upon
the Local Water Byelaws. Again any such connection must be
disconnected after use. A typical temporary filling loop is
shown in fig. 5.
Fittings manufactured from duplex (alpha-beta) brass are not
acceptable for underground use and certain water undertak-
ings will not accept their use above ground.
2.02.02 Safety valve
A safety valve complying with the requirements of BS 6750
Part 1 must be fitted close to the boiler on the flow 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.
2.02.03 Pressure gauge
A pressure gauge of minimum range 0-4 bar (0-60 Ibf/in2) with a fill pressure indicator must be fitted to the system,
preferably at the same point as the expansion vessel in an easily visible position.
2.02.04 Venting
A method of venting the system during filling and commissioning must be provided by fitting automatic air vents or by
venting manually.
2.02.05 Expansion vessel
In a sealed system an expansion vessel complying with the requirements of BS 4814 must be fitted 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 Specifications for
Domestic Wet Central Heating Systems.
VESSEL CHARGE
PRESSURE (bar)
INITIAL SYSTEM
PRESSURE (bar)
TOTAL WATER
CONTENT of SYSTEM
Litres
25
50
75
100
125
150
175
200
3.5
7.0
10.5
14.0
17.5
21.0
24.5
28.0
6.5
12.9
19.4
25.9
32.4
38.8
45.3
51.8
13.7
27.5
41.3
55.1
68.9
82.6
96.4
110.2
4.7
9.5
14.2
19.0
23.7
28.5
33.2
38.0
10.3
20.6
30.9
41.2
51.5
61.8
72.1
82.4
8.3
16.5
24.8
33.1
41.3
49.6
57.9
66.2
0.140 0.259 0.551 0.190 0.412 0.33
For syst. volumes other than
those given above, mult. the syst.
volume by the factor across.
0.5 1.0 1.5
1.0 1.5 2.0 1.5 2.0 2.0
EXPANSION VESSEL VOLUME (litres)
Sizing of expansion vessels:

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Sigma
2.02.06 Boiler water characteristics
If the water is harder than 18 clarke degrees, the water used should be treated to avoid possible scale in the boiler caused
by hard water or corrosion by aggressive water. It should be remembered that as a result of its low thermal conductivity,
even scale of just a few millimetres thick can lead to considerable overheating of the boiler walls, resulting in serious
problems.
IT IS ABSOLUTELY VITAL THAT THE WATER USED IS TREATED IN THE FOLLOWING CASES:
a) Extensive systems (containing large quantities of water);
b) Frequent additions of water to top-up the system.
If the system requires partial or total emptying, you are recommended to refill it with treated water.
2.02.07 Filling (sealed systems)
When cold, system pressure should be about 1 bar. If while running venting off of air dissolved in the water causes the
pressure of the central heating system to drop below the minimum level described above, the user must utilise a filling loop
to bring it back to the original value. During operation, water pressure in the boiler when hot should be about 1.5 - 2 bars.
After filling, always close and disconnect the filling loop.
Note - If there is a possibility of air pockets forming in certain points of the central heating system flow and return pipes,
you are recommended to fit an air vent valve at these points.
Note - When the boiler is installed below the level of the central heating system, single check valve should be fitted in the
eating flow to prevent gravity circulation around the heating circuit.
N.B. - The filling loop will be fitted by the installer at the time of fitting the system. It is NOT a part of the boiler.
2.03 Gas connection
Gas connection must be carried out using a rigid pipe.
The flow at the gas meter should be sufficient 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.
2.04 Wall Mounting
2.04.01 Drilling Template (Rear Flue Application)
120 min
220 min
Boiler
mounting
plate
254,5
620
Ø*
810 min
147
20 min
100
200 min
200
200 min 610 min
100
A
Fig. 6
Model
Sigma 30-40
Sigma 50-60
A
320
400

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Sigma
2.04.02 Wall mounting instructions for Rear Flue Application
1
Select suitable mounting position for
boiler. Refer to fig. 6 for dimensions and
minimum clearance. Using the template
or mounting plate mark flue 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 flue.
Drill cut a 118 mm diameter hole if it is
possible insert the flue-pipe from out-
side of the room; drill cut a 127 mm
diameter hole if to insert the flue-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 flue-pipe from inside of the room (core drill 127 mm hole)...
... or insert flue-pipe from outside of the room (core drill 118 mm hole).