Ferroli DOMINA 102 DGT User guide

Appr. nr. B99.06 A - CE 0461 AU 0431
DOMINA 102 DGT
Copper Wall-Mounted Combination,
Gas Fired Boiler for Central Heating
and Domestic Hot Water Production,
Fan Assisted, Room Sealed Compartment,
Electronic Flame Ignition and Control
3543879/1 - 07/2001
INSTALLATION, SERVICING AND
USER INSTRUCTIONS
G.C. NO: 47-267-24

2
DOMINA 102 DGT
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.
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"
"All CORGI Registered Installers carry a CORGI ID card and have a registration number. Both should
be recorded in your central heating log book. You can check the installer's CORGI registration by
calling CORGI on 01256 372300".
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. Please see installation and servicing guidelines.
INDEX
1. DESCRIPTION ....................................................................................................................................... 3
2. TECHNICAL AND DIMENSIONAL CHARACTERISTICS ...................................................................... 4
3. INSTALLATION DETAILS ....................................................................................................................... 9
4. COMMISSIONING AND TESTING ..................................................................................................... 22
5. ADJUSTMENT AND GAS CONVERSION........................................................................................... 23
6. MAINTENANCE AND CLEANING ..................................................................................................... 25
7. REPLACEMENT OF PARTS ................................................................................................................. 27
8. FAULT FINDING .................................................................................................................................. 32
9. ELECTRICAL AND FUNCTIONAL SCHEME....................................................................................... 39
10. USER INSTRUCTIONS ....................................................................................................................... 41

3
DOMINA 102 DGT
1. DESCRIPTION
1.01 Introduction
The Domina 102 DGT is defined as a “room sealed” combination 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 for central heating and
domestic hot water production. 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:
• Copper heat exchanger consisting of three finned tubes specifically shaped for high efficiency.
• There are three copper coils inserted in the three heating circuit tubes. These represent the domestic hot water
heat exchanger. Their shape and high exchange surface area enable the full output of the boiler to be absorbed.
• Ceramic fibre insulated combustion chamber
• 16 stainless steel bladed burners 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 with modulator, complete with pressure stabiliser.
• Flowmeter giving the domestic hot water circuit precedence over the central heating circuit.
• Pressure relief valve for the central heating circuit set to open at 3 bar.
• Built-in Expansion vessel.
• Variable speed pump.
• Central heating flow temperature adjustment thermostat.
• Domestic hot water flow temperature adjustment thermostat.
• Central heating limit thermostat.
• Overheat safety thermostat.
• Electronic control unit for automatic flame ignition and control.
• Central heating low water pressure cut off switch.
• Domestic hot water flow temperature sensor.
• Central heating flow temperature sensor.
• Safety bracket
1.02 Instructions and regulations
Assembly, installation, first start up and maintenance must be carried out by competent persons only, in accordance
with all current technical regulations and directives.
C.O.S.H.H.
Materials used in the manufacture of this appliance are non hazardous and no special precautions are required
when servicing.
Related Documents
This appliance must be installed strictly in accordance with these instructions.
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. 7593 1992 ............ TREATMENT OF WATER IN DOMESTIC HOT WATER CENTRAL HEATING SYSTEMS
B.S. 5546 1990 ............ INSTALLATION OF HOT WATER SUPPLIES FOR DOMESTIC PURPOSES
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
Model Water Bye Laws
For Northern Ireland the rules in force apply

4
DOMINA 102 DGT
Fig. 1
2. TECHNICAL AND DIMENSIONAL CHARACTERISTICS
2.01 Technical information
Domina 102 DGT boilers are central heating and domestic hot water heat generators and are produced as standard
to function with natural gas or liquid petrolium gas converted.
Key
1 - 3/4" central heating flow outlet
2 - 1/2" domestic hot water flow outlet
3 - 1/2 “ gas inlet
4 - 1/2" domestic hot water inlet
5 - 3/4" central heating return inlet
363
75
15 430
760
15
692
460
36 155
95 54 60
2
53
1
60
189
175
13 5
2
Top view
4
4
202
150
Ø80 Ø80 Ø80
120 12070
Bottom view

5
DOMINA 102 DGT
N.B. - The gas pressures at the burner and gas flows during the central heating phase given in the table refer
to nominal boiler output. To reduce this output (where necessary), gas pressure must be reduced until the
required output level is reached (see figures 4 and 5).
During domestic hot water production, gas pressures to the burner must correspond to the maximum output given
in table for the type of gas.
Gas pressure must be adjusted during maximum draw-off of domestic hot water.
• Maximum working temperature for central heating flow: 85°C
• Maximum temperature of domestic hot water: 55°C, adjustable between 40°C and 55°C.
• Minimum domestic cold water pressure required for 95% heat input:
- Flow restrictor fitted (standard) - 1,2 bar;
- Flow restrictor removed - 0,5 bar
Technical Data
MODEL Heat output Heat input
Net
Domestic ho
water heat
input
Gross
Boiler water
contents
Domestic hot
water circuit
contents
kW kW kW kW kW Litres Litres
Domina 102 DGT 30.0 12.7 33.1 14.5 30.0 1.5 0.8
LEDOMODEL
Connections Expansion vessel Max. working
pressure
central
heating
circuit
Max.
working
pressure hot
water circuit
12345Capacity Pre-pressurising
value
ØØØØØLitres bar bar bar
Domina 102 DGT 3/4” 1/2” 1/2” 1/2” 3/4” 010 1 3 6
MODEL
Main injectors (mm) Gas flow rates to main burners
for central heating Gas valve
Ø1/2”
G20 - NG G31 - LPG G20 - NG G31 - LPG
ØØ m
3
/h kg/h
Domina 102 DGT 16x1,25 16x0,75 3.5 2.6 H. V K4105G
MODEL
Gas supply pressures
working Gas pressure at main burner for central heating
Safety valve
G20 - NG G31 - LPG G20 - NG G31 - LPG
min. max. min. max.
mbar mbar mbar mbar mbar mbar bar
Domina 102 DGT 20 37 2,5 13,0 7,0 35,5 3
MODEL
Domestic hot
water production
with ∆t 30°C
Domestic hot
water production
with ∆t 35°C
Max. working
pressure domestic
hot water Protection
level
Weight
G20 - NG G31 - LPG
l/min. l/min. mbar mbar kg
Domina 102 DGT 14.3 12.3 13.0 35.5 IP44 48

6
DOMINA 102 DGT
2.03 Boiler water flow diagram2.02 Boiler main components
Key
5Room sealed compartment
7Gas inlet
8Domestic hot water outlet
9Domestic hot water inlet
10 Central heating flow outlet
11 Central heating return inlet
14 Safety valve
16 Fan
19 Combustion chamber
20 Burner assembly
21 Main injector
22 Burner
26 Combustion chamber insulation
27 Copper heat exchanger for central
heating and domestic hot water
28 Flue collector from heat exchanger
29 Internal flue exit
32 Central heating pump
34 Central heating flow temperature sensor
36 Automatic air vent valve
Fig. 2
Fig. 3
818222
29 43187
IN OUT
MIN
GRUNDFOS
FERROLI
114
34
20
21
90
50
16
28
32
26
19
49
132
5
56
27
91
10 8 784 85 44 136 14 42 9 11
36
145 62
OUT
I
MIN
AIR
IN
AIR
IN
FLUE
OUT
C.H.
OUT D.H.W. OUT GAS IN D.H.W. IN C.H. IN
42 Domestic hot water flow
temperature sensor
43 Air pressure switch
44 Gas valve
49 Safety overheat thermostat
50 Central heating flow limit thermostat
56 Expansion vessel
62 Time clock (option)
81 Ignition electrode
82 Sensor electrode
84 Primary gas valve solenoid
85 Secondary gas valve solenoid
90* Flue outlet test point
91* Air test point
114 Low water pressure cut off switch
132 Flue gas deflector
136 Flow meter
145 Central heating pressure gauge
187 Restrictor
*For use with flue gas analyser

7
DOMINA 102 DGT
2.05 Pump characteristics
The pump head available for circulating the water is
given in fig. 6.
N.B. - The pump is factory set at position 3. The pump
is a Grundfos type 15-50 UPS series.
Grundfos Pump performance graph
Note - Minimum flow through boiler heat exchanger at
any time should not fall below 6 litres per minute.
If the total volume of water in the system exceeds 40
litres an additional expansion vessel must be fitted to
the central heating return pipe.
Pump performance curve Grundfos UPS 15-50
Fig. 6
1 2 3 Speed settings
ABoilers pressure drop
BAvailable pump head C.H.
2.04 Central heating adjustment (not normally required)
To adjust boiler heat input (thus also regulating heat output to the central heating water) simply adjust the main
burner via the electronic control board (fig. 4, 5 and see paragraph 5.04 page 24).
The diagrams indicate the variation in heat output to the water as burner working pressure is varied.
Adjusting boiler output to the actual requirements of the central heating system will minimise boiler cycling thus
saving fuel, varying the output has virtually no effect on the efficiency and combustion characteristics of the boiler.
Diagram of pressures
and outputs with Natural gas
Fig. 4 Fig. 5
Diagram of pressures and outputs
with LPG (Propane)
2
3
4
5
6
7
8
9
10
11
12
13
12 13 14 15 16 17 18 19 20 21 22 23 24
11 12 13 14 15 16 17 18 19 20 21
kW
kcal/h
x 1000
mbar
14
25 26 27 28 29 30 31
22 23 24 25 26
kW
kcal/h
X 1000
m
b
ar
18 19 20 21 22 23
5
10
15
20
25
30
35
12 13 14 15 16 17
11 12 13 14 18 19 2015 16 17
25 26 27 28 29 3024
21 25 2622 23 24

8
DOMINA 102 DGT
SIZING OF ADDITIONAL EXPANSION VESSELS:
Deduct from the value given in the table the 10
litre vessel supplied.
Note:
1. Fill C.H. installation to min. 1.5 bar.
2. Expansion vessel must be fitted to central
heating return pipe.
3. The standard 10 litre expansion vessel is
charged to 1 bar.
4. The additional expansion vessel should be
charged to 1 bar.
SAFETY VALVE
SETTING (bar)
VESSEL CHARGE
PRESSURE (bar)
INITIAL SYSTEM
PRESSURE (bar)
TOTAL WATER
CONTENT of SYSTEM
3.0
0.5 1.0 1.5
1.0 1.5 2.0 1.5 2.0 2.0
EXPANSION VESSEL VOLUME (litres)
LITRES
25 3.5 6.5 13.7 4.7 10.3 8.3
50 7.0 12.9 27.5 9.5 20.6 16.5
75 10.5 19.4 41.3 14.2 30.9 24.8
100 14.0 25.9 55.1 19.0 41.2 33.1
125 17.5 32.4 68.9 23.7 51.5 41.3
150 21.0 38.8 82.6 28.5 61.8 49.6
175 24.5 45.3 96.4 33.2 72.1 57.9
200 28.0 51.8 110.2 38.0 82.4 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
Fig. 7
Pressure loss diagram
m |h
3
Q
8
7
6
5
4
3
2
1
00.5 1.5 2.512
H
mbar x 100

9
DOMINA 102 DGT
3. INSTALLATION DETAILS
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
theaboveRegulations,BuildingRegulations/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.
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 document IGE/UP/7. If in doubt advice should be sought from the Local Supplier.
Location of Boiler
The installation of the Domina 102 DGT must be on a suitable non-combustible load bearing wall which will provide an
adequatefixing for theboiler mounting safety bracketassembly. The location shouldbe in anarea where the waterpipes
will not be subjected to frost conditions. In siting the combination boiler the following limitations must be observed:
The combination 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 combination 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.
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.
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.
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, for NG and 37 mbar minimum for LPG.
Pipework from the meter to the combination boiler must be of an adequate size.
The boiler requires 3.5 m3/h of natural gas, and 2.60 kg/h of LPG.
Do not use pipes of a smaller size than the combination boiler inlet gas connection.
The complete installation must be tested for gas soundness and purged as described in BS6981-1988. All pipework
must be adequately supported. An isolating gas valve is provided and should be fitted on the boiler gas inlet. Please
wait 10 minutes when lighting from cold before checking gas rate. Gas pressures should be checked after the boiler
has operated for 10 minutes to reach thermal equilibrium.
Water System
Note - the boiler is designed for sealed systems only and must NOT be used on open vented systems.

10
DOMINA 102 DGT
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 heating system with domestic hot water circuit is illustrated in fig. 8.
Important - If thermostatic radiator vales are fitted 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.
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. 9.
Domestic Hot Water
Always fit a scale reducer in "hard water areas" (18 clarke degrees or over)". A 15mm copper connection point on
the boiler for attaching to the main supply is provided. The maximum domestic water pressure for the inlet supply
is 10 bar (145 P.S.I.). If the cold mains supply exceeds 5 bar (72 P.S.I.), a water governor or pressure reducing
valve must be fitted by the installer into the mains supply in an inconspicuous but accessible position preferable
between3 and 5metres (10-16ft) beforethe appliance. Such avalve must beapproved by theWater Research Council.
Attention - is drawn to the Model Water Byelaws.
Fittings manufactured from duplex (alpha-beta) brass are not acceptable for underground use and certain water
undertakings will not accept their use above ground.
Ensure all pipework is adequately supported
NOTE: A bypass must be fitted as far as possible
from the boiler if thermostatic radiator valves are
fitted thoughout.
Fig. 8
Gas
Cold water Additional expansion
vessel C.H.
Filling
point
Bypass
Key
1. Filling point C.H.
2. Temporary connection
3. Cold water supply
Fig. 9

11
DOMINA 102 DGT
Terminal Position
CLEARANCES:
* 600mm minimum clearance for
servicing access
460 5 min.5 min.
100 min.837
363 50 mm
600* min.
760
200 min.
Fig. 10
P
D, E
Q
Q
l
BC
A
G
F
L
J
HH
K
N
N
MM
Q
Directly below an opening, air brick, (0-7 kW)
opening windows, etc. (>7-14 kW)
(>14-32 kW)
(>32-70 kW)
Above an opening, air brick, (0-7 kW)
opening windows, etc. (>7-14 kW)
(>14-32 kW)
(>32-70 kW)
Horizontally to an opening, air brick, (0-7 kW)
opening windows, etc. (>7-14 kW)
(>14-32 kW)
(>32-70 kW)
Below gutters, soil pipes or drain pipes
Below eaves
Below balconies or car port roof
From a vertical drain pipe or soil pipe
From an internal or external corner
Above ground roof or balcony level
From a surface facing the terminal
(also see 6.1.2)
From a terminal facing the terminal
From an opening in the car port ( e.g. door,
window) into the dwelling
Vertically from a terminal on the same wall
Horizontally from a terminal on the same wall
From the wall on which the terminal is mounted
From a vertical structure on the roof
Above intersection with roof
Dimensions Terminal position
(kW input expressed in net)
Balanced flues room
sealed Open flues
Natural
draught Natural draught
Fanned
draught Fanned draught
Aa300 mm
600 mm
1500 mm
2000 mm
300 mm Not allowed 300 mm
Ba300 mm
300 mm
300 mm
600 mm
300 mm Not allowed 300 mm
Ca300 mm
400 mm
600 mm
600 mm
300 mm Not allowed 300 mm
D300 mm 75 mm Not allowed 75 mm
E300 mm 200 mm Not allowed 200 mm
F600 mm 200 mm Not allowed 200 mm
G300 mm 150 mmbNot allowed 150 mm
H600 mm 300 mm Not allowed 200 mm
I300 mm 300 mm Not allowed 300 mm
J600 mm 600 mm N/A 600 mm
K600 mm 1200 mm N/A 1200 mm
L1200 mm 1200 mm N/A 1200 mm
M1500 mm 1500 mm N/A 1500 mm
N300 mm 300 mm N/A 300 mm
ON/A N/A N/A 50 mm
PN/A N/A See Table 2
and Fig. 6b N/A
QN/A N/A See Table 2
and Fig. 4 150 mm
NOTE N/A = Not applicable
a
I n addition, the terminal should not be nearer than 150 mm (fanned draucht) or 300 mm (natural draught) to an opening in the building fabric formed for the purpose of accommodating
a built-in element such as a window frame, (see Figure C2). Separation distances are linked to the rated heat inputs as shown.
b
This dimension may be reduced to 75 mm for appliances of up to 5 kW heat input.
Fig. 11
Minimum dimensions of flue terminal positions

12
DOMINA 102 DGT
3.01 Drilling Template (Top Flue Application)
Select suitable mounting position for boiler, using the template mark flue outlet and boiler mounting points. Drill
two 10mm holes 90mm deep to accept the wall plugs, fit wall plugs. Fit two special wall plugs on the wall as described
in the fig. 12a. Fasten the wall bracket to the wall using an antitheft nut on the right side and a standard nut (M8)
on the left side. Mount the boiler on the wall bracket and fix using an antitheft nut on the left side and a standard
nut (M8) on the right side. Using a core drill cut a 118mm diameter hole for the flue.
1. CH flow (22 mm)
2. Safety Valve (15 mm)
3. Domestic hot water outlet (15 mm)
4. Gas supply (22 mm)
5. Domestic hot water inlet (15 mm)
6. CH return (22 mm) Fig. 12b
75
5 min
195 min
200 min
955 min
200
460 min
123 4 5 6
15 15
Ø3/4''Ø3/4'' Ø1/2''Ø1/2''Ø1/2''Ø1/2''
==
Ø120
jig bracket
Fig. 12a

13
DOMINA 102 DGT
3.02 Restrictor
For boiler operation, the restrictor supplied with the unit must be mounted following the instructions below.
Determine the correct size of flue restrictor required. Before inserting the flue gas duct in the boiler, check that the
restrictor fitted is correct and that it is correctly positioned (see fig. 13).
N.B.: the diameter of the hole is stamped
on the restrictor
No restrictor is required for back
outlet flue
Holes Ø: 47 50 52
Ø
Fig. 13
Choice of restrictor:
• With concentric pipes: - up to 1m long + one bend, use the 52 mm restrictor.
- for flue lengths over 1 metre, use no restrictor.
• With 2 pipe system: - Calculate the total flow resistance of the air and flue pipes in metres
(cap. 3.04.2)
- utilise the table shown below to choose the more suitable restrictor for
the flow resistance calculated
RESTRICTOR FOR TWO PIPE SYSTEM
ON DOMINA 102 DGT
Total flow resistance
of flue system
Use
restrictor
size
minimum maximum mm
0 m 20 m 47
20 m 35 m 50
35 m 45 m 52
45 m 50 m no restrictor

14
DOMINA 102 DGT
A 90°bend (fig. 15) is supplied for the horizontal connection of air and flue gas pipes. This can be angled towards
the chosen wall in degrees of 45°.
3.03 Top Outlet Concentric Flue Connection
3.03.1 Vertical concentric connection
L
A=L+(85-90)mm
Ø2
Ø1
25-30 mm 60
Ø2
Ø1
Ø1=100 Ø2=60
Fig. 15
Trim the 60 mm internal
diameter tube
Detail of mounting the bend
Averticalconnectorcanbesupplied forverticaldischarge
with concentric pipes.
Thesimple mountingand useof doublelip gasketsat the
joints makes this an extremely easy and safe option.
Fig. 14
Concentric
Vertical
Connector
3.03.2 Horizontal concentric connection

15
DOMINA 102 DGT
Fig. 16
Notes on concentric horizontal installation
To locate the centre of the hole for passing the
pipes through the wall, refer to fig. 12b. Bear in
mind that the two concentric pipes must slope
downwards away from the boiler at a rate of
about 3 mm/m to avoid rainwater entering the
boiler. The concentric pipes making up the air -
flue gas duct must be sealed with the gasket
where they join the boiler (fig. 16). Outside, the
pipes should protrude from the wall between 10
and 60 mm (fig. 16).
Between
10-60mm
3.03.3 Maximum concentric flue length
First table below shows the maximum flue lengths available for boilers with concentric systems.
For correct calculation remember to include the reduction for bends on second table. Please refer to 3.02 for use
of restrictor
Maximum flue lenght permissible 100 mm concentric 125 mm concentric
Vertical Horizontal* Vertical Horizontal*
Domina 102 DGT 4 m 3 m 5 m 5 m
Reduction for bend
100 mm concentric bend 90°1 m
100 mm concentric bend 45°0,5 m
125 mm concentric bend 90°0,5 m
125 mm concentric bend 45°0,25 m
*For horizontal Flueing the reduction for appliance bend or turret are already included.
max. 3 m
max. 4 m
Fig. 17a Fig. 17b

16
DOMINA 102 DGT
Fig. 18
Ø80Ø80
AIRFLUE
1
2
3.04 Top Outlet: Two Pipe Flue System
3.04.1 Two pipe connection
Two separate ducts Ø80 for air intake and flue gas
discharge can be directly connected to the boiler.
For conversion mount the separate outlet kit 1 to top
outlet (see 3.03)
Insert blanking plate 2
in remaining air intake
Connect flue duct to central hole Ø80 and air duct to left or right air intake hole Ø80. Insert blanking plate 2 in
remaining air intake.
A varied selection of accessories for two pipe systems are available from Ferroli (ref. to page 17). Before installing
your system please check via calculation table at 3.04.2 you are not exceeding the maximum permissible length for
the appliance.
IMPORTANT:
Notes on two pipe system installation:
When using the two pipe system the flue discharge pipe must have a 25mm air gap when passing through
combustible materials. Where the flue discharge pipe passes through the airing space of an airing cupboard it must
be protected by a non combustible guard or expanded metal giving an annular air gap of at least 25mm.
Where the flue discharge pipe passes through a wall containing cavity insulation, a non combustible sleeve must be
fitted. Additionally a gap of 25mm between the sleeve and the insulation should be provided by cutting back the
insulation or packing loose fill bead insulation with mineral fibre. Where the flue pipe is run through an unheated roof
space it should be insulated with non combustible insulating material to prevent condensation. The flue pipe should
be supported at intervals of not more than 1.8m and the support should be preferably below a joint.
3.04.2 Two pipe flue system
To determine the maximum length of flue and air pipe permissible.
The calculation is based on a standard reference resistance of 1 metre of 80 mm horizontal air intake pipe. For every
configuration of the two-pipe system all components will have a resistance factor based upon this reference. (I.e. a
90 degree bend fitted in the flue line would attract a resistance factor equivalent to 2.5 Metres of horizontal 80mm
pipe). This is expressed as X metres. Each boiler will have a maximum equivalent length of flue/air pipe and this is
shown in the table as N metres. Therefore when calculating the proposed flue run the equivalent resistance of every
length of pipe and every bend, whether air intake or flue discharge is added together to give an actual total flue
length. The final figure calculated must not exceed the permitted maximum length (N metres) for each boiler type.
Calculation Routine
1. Identify all the components needed to complete the proposed flue/air pipe run.
2. Calculate the sum of all the equivalent lengths (see table at next page).
3. For boilers, which may require a flue restrictor, refer to table at page 13 (par. 3.02) to ascertain the correct size
and add this resistance to your total.
4. Check and verify that the total flue/air pipe length (flow resistance) does not exceed 50 mt. maximum permit-
ted for Domina 102 DGT.
IMPORTANT: Resistance factors apply to standard férroli components only.

17
DOMINA 102 DGT
AIR FLUE
Vertical Horizontal Vertical Horizontal
Description
Male-female flue/Air pipe
1 m - Ø 80
Female-female bend
45°Ø 80 m
Male-female bend
90°Ø 80 m
Dscription
Horizontal
flue terminal
Ø 80 mm
Air intake
terminal
Ø 80 mm
Outlet flue/air inlet
for concentric system
Ø 100/60 mm
Pipe fitting for
outlet flue
Ø 80 mm
Outlet flue/air inlet
for connection
with split end
Ø 80 mm
1112
1,2 2,2
1,5 2,5
REDUCTION
5
2
4
AIR FLUE
Vertical Horizontal Vertical Horizontal
REDUCTION
12
A
c
c
e
s
s
o
r
i
e
s
Ø
8
0
A
c
c
e
s
s
o
r
i
e
s
Ø
8
0
Spigot-and-socket
reduction Ø 100/80 mm
0
3.04.2 (continued)
Tab. 1 - Pipes and
fittings reduction table

18
DOMINA 102 DGT
For further accessories please refer to:
"Flue system manual for room sealed boiler"
Example of calculation for wall inlet/outlet
with 2 pipe system
maximum total flue length: 50 metres
Attention:
Remove the flue diaphragm.
The flue + air Pipes must have a 3% drop away
from the boiler to outside
7 6 325 1
13 m 13 m
Fig. 19
Example of wall inlet/outlet
2 pipe application
Example of roof inlet/outlet
Example of direct roof flue outlet
and wall air inlet
3.04.3 Example of other installation with two pipe systems
Fig. 20a
Fig. 20b Fig. 20c
REF. N ° OF PIECES DESCRIPTION LENGTH OR
REDUCTION
1 1 Air bend 80 mm R/D = 0,75 1,5 m
2 13 Horizontal air pipe 13,0 m
3 1 Air wall terminal 2,0 m
5 1 Flue bend 80 mm R/D = 0,75 2,5 m
6 13 Horizontal flue 26,0 m
7 1 Air wall terminal outlet flue 5,0 m
TOTAL 50,0 m

19
DOMINA 102 DGT
3.05 Connecting the central heating and domestic hot water circuits
Connect to the relevant connections as indicated in fig. 1. Connect the pressure relief valve discharge pipe (15mm)
to the outside of the building, where possible over a drain. The discharge must be such that it will not be hazardous
tooccupants andpassers-by orcause damageto externalelectric componentsor wiring. The pipeshould bedirected
towards the wall. To ensure long life, the heating circuit should be correctly sized and fitted with all the controls
necessary to ensure correct functioning and operation. The differential between the boiler flow and return pipes
should not be more than 20°C. You are advised not to use the boiler with return temperatures of less than 50°C in
order to prevent patches of condensation forming, having a corrosive effect on boiler components.
3.06 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;
c) Domestic hot water circuits
If the system requires partial or total emptying, you are recommended to refill it with treated water.
3.07 Filling
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 0.5 bar, the user must utilise a filling loop to bring it back
tothe original value. During operation,water pressure in the boilerwhen hot should be about1.5 - 2 bars. Afterfilling,
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 a system, single check valve should be fitted
in the flow to prevent gravity circulation around the heating system.
3.08 Gas connection
Gas connection should be carried out using a rigid pipe.
The flow at the gas meter should be sufficient for the simultaneous use at full gas rate of all appliances connected
to it. Connect the gas supply to the boiler according to current regulations. The diameter of the gas tube 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 and in any instance should not be less than 22mm.
The whole of the gas installation including the meter should be inspected and tested for soundness and purged
in accordance with BS6891-1988.
N.B. - The filling loop will be fitted by the installer at the time of installing the system. It is NOT a part of the boiler.
3.09 Electrical connection
The boiler must be connected to a single phase 230 V 50 Hz electricity supply with a 3 A max. fuse and a bipolar switch
with contact opening of at least 3 mm fitted between the boiler and the electricity supply. The boiler must always
be connected to an efficient earth installation. Under the electrical box, there is a 3 pole terminal block for connecting
the boiler to the mains (230 V 50 Hz) and a 2 pole board for connecting a room thermostat (RT). To connect, undo
the screws fixing the terminal block box and connect the wires, ensuring correct polarity of the terminals. It should
be noted that there is low voltage (24 V) between the room thermostat contacts.
When the boiler is connected to an electricity main, it is essential TO OBSERVE CORRECT POLARITIES (LIVE: brown
cable, NEUTRAL: blue cable, EARTH: yellow-green cable).
All wiring must conform to current I.E.E. regulations.

20
DOMINA 102 DGT
Note: If the power supply cable has to be replaced, use “0.75mm (24/0.20) heat resisting cable only to
BS6500 with a maximum external diameter of 8 mm.
Note - When connecting a room thermostat or external timer, do not link the power supply of these devices to the
switching contacts. The switch contacts must be voltage free. Any mains powered devices must utilise mains power
solely to drive the timer motor.
Applying mains voltage to the switch contacts will irreparably damage the circuit board.
Although this boiler can also be used without a room thermostat, you are recommended to install one for the
following reasons:
Greater comfort conditions due to more accurate control of room temperature.
Greater energy savings.
3.10 Differential air pressure switch (fig. 2 - part 43)
The differential air pressure switch is a safety device which allows the main burner to ignite only after having verified
that the fan is working correctly. If the difference in pressure between the flue gas discharge pipe and the air intake
pipe is not at least equal to the minimum pressure switch calibration value, the pressure switch contacts do not close
and the gas valve is thus prevented from opening. In addition, the electrical circuit of the boiler is designed so that
if for any reason the air pressure switch contacts remain closed when the fan stops, the burner will not start up again.
3.11 Checks
Fill the central heating system as described previously (3.07) and check there are no leaks in the domestic hot water
and boiler water circuits. Check that there are no gas leaks on the boiler or the supply to the boiler. Also check that
the electrical connections are correct.
3.12 Installing a room thermostat (72) (fig. 21b)
To connect the thermostat:
Open the electrical box on the base of the appliance and remove the “jumper cable” between terminals 3 and 4.
Connect the room thermostat (72) as shown in figure 21b.
3.13 Ferroli Domina boiler programmer fixing (optional)
- Remove outer case by removing two securing screws from the rear bottom corners and lift off.
- Remove screw securing facia panel and swing facia panel down.
- Remove rear cover from facia.
- Remove clock blanking plate
from the boiler facia panel.
- Mount clock into facia panel
using two screws and spacers
provided.
- Take the black cable
containingtheblue andbrown
wires and connect the loose
spades to clock terminals 1 &
2.
- Connect the plug end of the
cable to terminal X2 of main
circuit board.
- Remove the connector link
from the 2 wires located
behind the clock position.
- Connect these to terminal 3
and 5 of the clock.
- Replace everything in reverse
order.
- Pleasereferto page48of User
manual for use of time clock
Fig. 21a
Existing wiring
65874321
72
10987654321
1312
1514121110
1245678101112
X4
X2X1
131415
X5
X6 X7
1
2
3
6
7
8
9
10
11
12
DMF03
NL
4
5
13