Riello INSIEME EVO 25 Manual

cod. 20113821 rev. 2 07/2016
INSIEME EVO 25
EN INSTALLATION AND MAINTENANCE MANUAL

2
Dear heating engineer,
Congratulations on having chosen a Rboiler. You have
selected a modern, quality product that is designed to give
dependable, efcient and safe service and to provide comfort
in the home for many years to come.
This manual provides information that is essential to the
installation of the appliance. Used in conjunction with your
own knowledge and expertise it will enable you to install the
appliance quickly, easily, and correctly.
Please accept our thanks and our congratulations on your choice
of product.
Riello S.p.A.
CONFORMITY
INSIEME EVO 25 boilers conform to the following directives:
−Directive 92/42/EEC on efciency requirements
−Electromagnetic Compatibility Directive 2014/30/EU
−Low Voltage Directive 2014/35/EU
−Ecodesign Directive 2009/125/CE for energy-related
products
−Energy Labelling Directive 2010/30/EU
−Delegated Regulation (EU) N. 811/2013
−Delegated Regulation (EU) N. 813/2013
9 This product must only be used for the purpose for which it
is designed and made, as specied by R. Rdeclines
all responsibility, contractual or other, for damage to
property or injury to persons or animals caused by improper
installation, adjustment, maintenance or use.
ENGLISH
RANGE
MODEL CODE
INSIEME EVO 25 20108987
ACCESSORIES
For a complete list of accessories and details of their compatibility,
refer to the Catalogue.

3
This manual, Code 20113821 - Rev. 2 (07/2016)
comprises 44 pages.
CONTENTS
The following symbols are used in this manual:
9 CAUTION! = Identies actions that require caution and
adequate preparation.
0 STOP! = Identies actions that you MUST NOT do.
This manual, Code
- Rev.
comprises
pages.
1 GENERAL INFORMATION ............................4
1.1 General Safety Information ......................4
1.2 Precautions..................................4
1.3 Description of the appliance .....................5
1.4 Safety devices ................................5
1.5 Identication ................................5
1.6 System layout ................................6
1.7 Technical specications.........................8
1.8 Central heating system pump ....................9
1.9 Location of sensors ........................... 10
1.10 Control panel ................................11
2 INSTALLATION .....................................12
2.1 Unpacking the product ........................ 12
2.1.1 Positioning of labels .......................... 12
2.2 Overall dimensions and weights ................. 12
2.3 Moving and removing the packing ............... 13
2.4 Installation premises ......................... 14
2.4.1 Recommended minimum distances .............. 14
2.5 Installation in older systems and systems requiring
modernisation .............................. 14
2.6 Water connections ........................... 15
2.7 Boiler water circuit ........................... 15
2.8 Typical water system schematics ................. 16
2.9 Fuel connections..............................17
2.10 Hoses should also be xed to the oor and suitably
protected whenever possible ................... 18
2.10.1 Technical specications of stack ................. 18
2.10.2 Connection to the stack ....................... 18
2.11 System lling and emptying .................... 19
2.11.1 Water quality requirements..................... 19
2.11.2 Filling ..................................... 19
2.11.3 Emptying ..................................20
2.12 Wiring diagram .............................. 21
2.13 Electrical connections ......................... 22
3 COMMISSIONING AND MAINTENANCE...............24
3.1 Preparing for initial startup .....................24
3.2 Initial startup ...............................24
3.2.1 Ignition failure ..............................24
3.2.2 Resetting the burner and safety thermostat ........25
3.3 Checks during and after initial start-up ...........25
3.3.1 Storage cylinder pump control ..................26
3.3.2 Burner control and adjustment.................. 27
3.3.3 Burner functioning and programming ............28
3.4 Temporary shutdown .........................36
3.5 Preparing for extended periods of disuse ..........36
3.6 Cleaning and servicing the boiler ................ 37
3.7 Annual cleaning ............................. 37
3.7.1 Cleaning and maintaining the burner............. 37
3.7.2 Cleaning the boiler ...........................39
3.7.3 External cleaning ............................40
3.8 Troubleshooting ............................. 41
4 RECYCLING AND DISPOSAL ........................42

4
GENERAL INFORMATION
1 GENERAL INFORMATION
1.1 General Safety Information
9 Check that the product is complete, undamaged and as
ordered as soon as you receive it. Report any discrepancies
or damage to the Rdealer who sold it.
9 This product must be installed by a legally qualied heating
engineer. On completion of the installation, the installer
must issue the owner with a declaration of conformity
conrming that the installation has been completed to
the highest standards in compliance with the instructions
provided by Rin this instruction manual, and that it
conforms to all applicable laws and standards.
9 This product must only be used for the purpose for which it
is designed and made, as specied by R. Rdeclines
all responsibility, contractual or other, for damage to
property or injury to persons or animals caused by improper
installation, adjustment, maintenance or use.
9 The room where the boiler is installed must be properly
ventilated to ensure a sufcient supply of air for correct
combustion.
9 If you notice any water leaks, disconnect the boiler from the
mains electricity supply and shut off the water supply.
9 The boiler must be serviced at least once a year.
9 Periodically check that pressure in the central heating
circuit, when cold, is approximately 1.5 bar and below the
maximum limit specied for the boiler.
9 If the boiler is not going to be used for an extended period of
time, perform the operations described later in this manual.
9 This manual is an integral part of the equipment and
therefore must be stored carefully and must ALWAYS
accompany the boiler even if it is sold to another Owner or
User or transferred to another plant. If it is damaged or lost,
request another copy from your local Technical Assistance
Service R.
1.2 Precautions
The operation of any appliance that uses fuel, electrical power
and water demands that a number of fundamental safety
precautions be respected:
0 Do not allow children or inrm persons to operate the
system unsupervised.
0 It is forbidden to use electrical devices or equipment, such
as switches, appliances, etc. if there is a smell of gas or un-
burnt products. If so:
−Ventilate the room, opening doors and windows
−Close the fuel shut-off cock.
0 Do not touch the boiler while barefoot or wet.
0 Never clean or service the boiler without rst disconnecting
it from the mains electricity supply by turning the mains
power switch and the control panel switch OFF.
0 Do not tamper with or adjust the safety or control devices
without prior authorisation and instructions from the
manufacturer.
0 Never pull, disconnect, or twist the electrical cables coming
from the appliance even if it is disconnected from the mains
electricity supply.
0 Do not obstruct or restrict the vents in the room where
the boiler is installed. Adequate ventilation is essential for
correct combustion.
0 Do not expose the boiler to the elements. It is not designed
for use outdoors.
0 It is prohibited to leave inammable substances and
containers in the room where the boiler is installed.
0 Do not dispose of packaging material into the environment,
or leave it within the reach of children, since it can become
a potential hazard. Dispose of packaging material in
compliance with applicable legislation.
0 It is forbidden to operate the boiler without water.

5
GENERAL INFORMATION
1.3 Description of the appliance
The INSIEME EVO 25 boiler is a hot water boiler for central heating
systems. It can function at low temperature and is oil fuelled.
The single stage oil burner has a vertical steel combustion
chamber. The boiler body is thoroughly and effectively insulated
with a layer of high density glass wool. The INSIEME EVO 25
boiler's control logic incorporates a total shutdown function
to minimise energy consumption. The boiler only starts up if
the central heating system requests heat (i.e. when the room
thermostat switches the heating on).
1.4 Safety devices
INSIEME EVO 25 boilers incorporate the following safety and
control devices:
−A manual reset safety thermostat that forces a safety
shutdown if boiler temperature exceeds the safety
threshold (100°C). The sensor used to monitor this
temperature is located on the body of the heat exchanger;
−A minimum temperature thermostat that enables the
central heating pump only if boiler temperature exceeds
the minimum permissible (50°C);
−An electronic burner controller that monitors the correct
functioning of the selected burner program and sends
a lockout signal to the control panel in the event of an
error.
9 The intervention of a safety device indicates a potentially
dangerous malfunction in the system. Contact the
manufacturer’s Technical Assistance Service immediately.
9 Safety devices must only be replaced by the manufacturer's
Technical Assistance Service using original spare parts. Refer
to the spare parts catalogue supplied with the boiler.
0 Do not use the boiler if any of its safety devices are faulty.
Always check that the boiler is functioning correctly after repairs
have been made.
1.5 Identication
The products are identied by:
Serial number plate
This is located on the boiler body and species the serial
number, model, and main technical specications.
Pms= bar T = °C
Qn(min)=
Pn(min)=
TIPO/TYP/TYP/TYPE/TIPO/TIPO:
COMBUSTIBILE/COMBUSTIBLE/BRENNSTOFF/BRANDSTOF/FUEL/COMBUSTIBLE/COMBUSTÍVEL:
Qn(max)=
Pn(max)=
Mod.
Cod.
N°
kW
kW
kW
IP
WV~Hz
RIELLO S.p.A.
Via Ing.Pilade Riello 7
37045 Legnago (VR) - ITALY
PAESE DI DESTINAZIONE/PAYS DE DESTINATION/BESTIMMUNGSLAND/LAND VON BESTEMMING
COUNTRY OF DESTINATION/PAÍS DE DESTINO/PAÍS DE DESTINO:
T067815GE
kW
S
X
%
mg/kWh
NO
Mod.
Cod.
N°
Qn(max) kW
Pn(max) kW
bar
Pms
RIELLO S.p.A.
Via Ing.Pilade Riello 7
37045 Legnago (VR) - ITALY
T067815GE
Data plate
This lists the technical specications and performance of the
product.
Central heating section
Qn Rated heat input
Pn Rated useful heat output
IP Electric degree of protection
Pms Maximum operating pressure, CH circuit
TTemperature
η Efciency
D Specic ow rate
NOx NOx class
9 If these plates or any other means of clearly identifying the
product are defaced, removed or lost, proper installation
and servicing may be rendered difcult.

6
GENERAL INFORMATION
1.6 System layout
INSIEME EVO 25
5
6
3
4
7
8
9
10
12
13
14
11
15
16
17
17
18
1
2
1 Safety valve
2 Fuel oil hoses
3 Control panel
4 Sensor sockets
5 Capillary pressure gauge tting
6 CH circuit expansion vessel
7 Burner
8 Drain cock
9 Central heating system pump
10 Water tting for storage cylinder (if installed)
11 Flame inspection window
12 Boiler body
13 Fuel oil lter
14 Serial number plate
15 Flue gas exhaust tting
16 Flue gas box cover
17 Lifting bracket
18 Automatic bleed valve

7
GENERAL INFORMATION
BURNER
3
9
11
5
6
2
7
8
10
1
4
1 Pump
2 Burner controller
3 Reset button with lockout indicator
4 Flange with seal
5 Air damper adjuster screw
6 Air intake
7 Oil pump pressure adjuster screw
8 Pressure gauge tting
9 Photoresistor
10 Combustion head
11 Motor
OIL PUMP
7
6
5
4
3
2
1
8
1 Suction port
2 Return
3 By-pass screw
4 Pressure gauge tting
5 Pressure adjuster screw
6 Vacuum gauge tting
7 Valve
8 Auxiliary pressure measurement tting

8
GENERAL INFORMATION
1.7 Technical specications
DESCRIPTION INSIEME EVO 25
Device type
Low temperature
central heating
B23
Fuel Heating fuel oil
(light oil)
Maximum rated heat input at furnace referred to HVC (LCV) 27,5 (26) kW
Useful (rated) heat output 25 kW
Maximum useful heat output P4 (60-80°C) 24,7 kW
30% heat output P1 with return at 37°C 7,4 kW
Efciency class in central heating mode B
Seasonal energy efciency in central heating mode ηs 86 %
Efciency at rated heat output in high temperature
mode referred to HCV η4 Pn (60-80°C) 89,6 %
Efciency at 30% rated heat output in low
temperature mode referred to HCV η1 with return at 37°C 91 %
Heat loss in standby mode Pstby 44 W
Combustion efciency referred to LCV 96 %
Annual energy consumption QHE 82,6 GJ
Noise level (sound power) LWA 60 dB(A)
Emissions at maximum heat input
NOx (referred to HCV) 170 mg/kWh
CO2 12,5 %
CO w.a. < 20 ppm
Flue gas T At Pn (60-80°C) 110 °C
Smoke scale < 0,5
Flue gas mass ow rate 10,0 g/s
Maximum working pressure 3bar
Safety thermostat trip temperature 100 °C
Maximum operating temperature 55-82 °C
Minimum return temperature 37 °C
Boiler water capacity 30 l
Turbulators 19
Volume of expansion vessel (CH) 8 l
Precharge of expansion vessel (CH) 1,5 bar
Index of protection X0D IP
Power supply 230 V - 50 Hz
Absorbed power supply (max) 184 W
Consumption at full load Elmax 131 W
Consumption at part load Elmin 39 W
Electrical consumption in standby mode P sb 12 W
LCV: Lower caloric value of fuel
HCV: Higher caloric value of fuel
Test conditions:
−Room temperature 22°C
−Atmospheric pressure 1018 mbar

9
GENERAL INFORMATION
1.8 Central heating system pump
DESCRIPTION INSIEME EVO 25
Electrical consumption 53 W
EEI Part 3 (*) ≤0,20
P L,Avg (**) ≤24 W
Minimum pressure at pump suction inlet 0,5 bar
(*) Energy efciency rating according to regulations 641/2009-622/2012
(**) Approximate average annual electricity consumption according to regulations 641/2009-622/2012
PUMP CURVES
0
1
2
3
4
5
Q [m³/h]
0,0 0,2 0,4 0,6 0,8 1,0 1,2 1,4 1,6 1,8 2,0 2,2 2,4 2,6 2,8 3,0 Q [m³/h]
6
7
[m]
H
0
10
20
30
40
50
60
[kPa]
0,0 0,2 0,4 0,6 0,8 1,0 1,2 1,4 1,6 1,8 2,0 2,2 2,4 2,6 2,8 3,0
p
0,0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9
0
1,0
Q [l/s]
10
20
30
40
50
[W]
P1
Residual head
Flow-rate
The curves refer to a water density of 983.2 Kg/m3, a water temperature of +20°C, and a kinematic viscosity of 0.474 mm2/s (0.474
cSt).

10
GENERAL INFORMATION
1.9 Location of sensors
INSIEME EVO 25
Tm
1
TS
TR
2
TS Safety thermostat sensor
Tm Minimum temperature thermostat
sensor
TR Boiler thermostat sensor
1 Boiler temperature gauge
2 Boiler temperature gauge socket

11
GENERAL INFORMATION
1.10 Control panel
INSIEME EVO 25
20 100
4
40 60 80
321
0
0120
7
1
2
4
5
6
3
8
1 Function selector
0 Off
IOn
II Burner reset
2 Boiler temperature gauge
Displays the temperature of the central heating water
3 Boiler pressure gauge
Displays the pressure in the central heating circuit.
4 Boiler thermostat
Allows you to set the temperature of the central heating water (setting range 55-82°C)
55
82
5 Electrical power indicator (green)
Lights to show that the boiler is receiving electrical power
6 Burner lockout indicator (red)
Lights to show that the burner locked out
7 Manual reset for safety thermostat
Allows you to reset the boiler if the safety thermostat trips. Unscrew the protective cover to access
the reset button

12
INSTALLATION
2 INSTALLATION
2.1 Unpacking the product
The INSIEME EVO 25 boiler is supplied on a pallet, protected by a
non-scratch cloth and a triple wall cardboard box.
The following items are delivered in a plastic bag (1) inside the
boiler:
−User manual
−Installation and maintenance manual
−Spare parts catalogue
−Hydraulic test certicate
−Energy label
2.1.1 Positioning of labels
A
A Packing label
9 The instruction manual is an integral part of the boiler. Once
located, read it thoroughly and keep it safe.
9 Keep the documentation envelope in a safe place. Any
replacement documents must be ordered from Riello
S.p.A. who reserve the right to charge for the cost of the
replacement.
2.2 Overall dimensions and weights
INSIEME EVO 25
P
H
L
1
Description INSIEME EVO 25
L450 mm
P640 mm
H905 mm
Net weight 105 kg

13
INSTALLATION
2.3 Moving and removing the packing
9 Wear suitable personal protection equipment when moving
the boiler and removing the packing. Only use lifting
equipment that is suitable for the weight involved.
Proceed as follows to remove the packing:
−remove the straps (A) xing the packing to the pallet;
A
−remove the cardboard packing and non-scratch cloth.
0 Do not dispose of packaging material into the environment,
or leave it within the reach of children, since it can become
a potential hazard. Dispose of packaging material in
compliance with applicable legislation.
With the packing removed, remove the front panel (1).
1
Locate the bag containing the documentation, remove the
energy label and apply it to the boiler casing.
25 kW
30 mm
25 mm

14
INSTALLATION
To move the boiler manually, proceed as follows:
−unscrew the screws (1) securing the boiler to the pallet
−remove the top panel (2)
−lift the boiler using the brackets provided in the body.
Use lifting equipment suitable for the weight involved.
2
1
1
9 Take care because the boiler might swing when lifted.
2.4 Installation premises
INSIEME EVO 25 boilers must be installed in rooms with suitably
sized air vents conforming to the technical standards and
regulations applicable at the place of installation.
9 When installing the boiler, allow sufcient space around it
to access all safety and control devices and to permit easy
maintenance.
9 Check that the appliance's electrical protection level is
suitable for the place of installation.
9 Make sure that comburent air is not contaminated by
substances containing chlorine or uorine (elements found
in sprays, paints, detergents etc.).
0 These boilers must be installed indoors. They are not
designed for outside use.
0 Do not obstruct or restrict the air vents in the room where
the boiler is installed. A free air supply is essential for correct
combustion.
2.4.1 Recommended minimum distances
This gure shows the minimum installation distances that must
be respected in order to allow proper maintenance of the boiler.
≥ 1 m
≥ 1 m
≥ 1 m
≥ 0,5 m ≥ 0,5 m
2.5 Installation in older systems and systems
requiring modernisation
When installing these boilers in older systems or systems
requiring modernisation, always perform the following checks:
−Make sure that the ue is able to withstand the
temperature of the combustion gases and that it has
been designed and made in compliance with applicable
standards. The ue must also be as straight as possible,
sealed, insulated and not blocked or choked
−Make sure that the electrical supply system has been
installed by a qualied electrician in compliance with
applicable standards
−Make sure that the fuel feed line and any storage tank
are made and installed in compliance with applicable
standards
−Make sure that expansion vessels are big enough to
contain the additional volume generated by thermal
expansion
−Make sure that the ow rate, head and direction of ow
of the pumps are suitable and correct
−Make sure that the central heating circuit has been
ushed out to remove all sludge and lime scale, and that
it has been bled and seal tested
−Make sure that a suitable water treatment system is
installed if the quality of the supply/recirculation water
so demands. (Refer to the reference values on page 19);
See Riello S.p.A.’s Catalogue
9 The manufacturer declines all responsibility for damage
caused by incorrectly constructed ue systems.

15
INSTALLATION
2.6 Water connections
The following table gives the dimensions and positions of the
water ttings for INSIEME EVO 25 boilers.
Before installing the boiler, ush out all the pipes of the central
heating circuit to remove any machining residues.
MI
RI
Central
heating flow
A
B
C
D
E
F
G
Central
heating return
DESCRIPTION INSIEME EVO 25
A790 mm
B450 mm
C37 mm
D75 mm
E298 mm
F350 mm
G540 mm
MI (CH ow) 3/4 M Ø
RI (CH return) 3/4 M Ø
9 To avoid damaging the appliance, while the burner is
functioning there must be a minimum water ow rate of
about 25% maximum ow rate with ΔT= 10°C. Use a suitable
pump if necessary.Water return temperature in continuous
service must be ≥37°C.
2.7 Boiler water circuit
2
4
3
5
7
1
Central
heating return
Central
heating flow
SYSTEM LAYOUT
6
1 Boiler body
2 Automatic vent valve
3 Pump
4 Safety valve
5 Burner
6 Expansion vessel
7 Drain cock

16
INSTALLATION
2.8 Typical water system schematics
1 Disconnect valves
2 CH radiator
3 DHW pressure reducer
4 Safety drain
5 Non-return valve 1
2
5
1
4
1 13
9 The safety valves must be connected to a suitable collection and drain system.
9 The choice of system components and the method of their installation are left up to the heating engineer installing the system.
Installers must use their expertise to ensure proper installation and functioning in conformity to all applicable legislation.
9 If needed, water supplies and recovery circuits must be conditioned by suitable treatment systems. Refer to the values listed in
the table on page 19.
9 The boiler can be connected to an ATRB 120 storage cylinder using the relevant kits (see the Catalogue).

17
INSTALLATION
2.9 Fuel connections
The INSIEME EVO 25 boiler is designed to receive fuel oil hoses
through the holes (1) in the rear panel.
The fuel oil supply pipe must be connected directly to the lter
(2) and the return pipe to the tting (3).
Make sure that these connections are oil tight.
2
3
1
Description INSIEME EVO 25
Fittings 2x3/8" M Ø
If the oil feed system is in negative pressure, the return line must
reach the same height as the suction line. This avoids having to
install a bottom valve, which would be essential if the return
hose were to be located above the level of the fuel.
9 The installer must ensure that the negative pressure
differential in the oil feed never exceeds 0.4 bar (30 cm Hg).
If this value is exceeded, the fuel oil will release gas. Make
sure that the oil hoses are perfectly oil-tight.
9 Clean out the oil tank at suitable intervals.
9 The oil feed line must be suitable for the ow rate demanded
by the burner. The oil feed system must also be equipped
with all the necessary safety and control devices required
by applicable legislation and standards. Refer to the table
alongside for oil feed line characteristics.
9 A lter must be installed in the oil feed line.
9 Make sure that the oil return line is not kinked or blocked
before starting up the boiler. Excessive back-pressure can
cause the pump seal to fail.
Priming the pump
To prime the oil pump simply start up the burner and check for
a ame.
If the burner enters lockout before any fuel reaches it, wait at
least 20 seconds then turn the function selector to position
(II) "Reset burner" for at least 1 second before returning it to
position (I). Wait for the burner to complete the entire ignition
cycle again, up to the ignition of the ame.
(*)
max. 4 m
H
H
(*) Automatic shut-off device (if tted). For details of the
electrical connections, see the “Automatic shut-off
device (DAI)” section on page 21.
H (m) L (m)
Øi (8mm) Øi (10mm)
035 100
0,5 30 100
125 100
1,5 20 90
215 70
3 8 30
3,5 620
H = Height difference
L = Maximum length of suction hose
Øi = Internal diameter of hose
1 Suction port
2 Return
3 By-pass screw
4 Pressure gauge tting
5 Pressure adjuster screw
6 Vacuum gauge tting
7 Valve
8 Auxiliary pressure measurement tting
7 6 5 4 3 2
1
8

18
INSTALLATION
2.10 Hoses should also be xed to the oor and
suitably protected whenever possible
The ue pipe (1) and the connection to the stack (2) must be
made in conformity to the laws, standards and regulations
applicable in the place of installation.
2
≥5°
1
3
9 The condensate drain system (3) must conform to national
and local legislation and standards.
9 The stack tting is equipped with a seal (A). Do not use pipes
with riveted overlaps to construct the ue.
A
Øi 120
195
114
INSIEME EVO 25 boilers derive their comburent air from the room
in which they are installed. Suitable air vents must therefore be
provided in compliance with applicable laws and standards.
0 Do not obstruct or restrict the air vents in the room where
the boiler is installed. Adequate ventilation is essential for
correct combustion and functioning.
2.10.1 Technical specications of stack
The stack must satisfy the following requirements::
−It must be constructed from materials that are
impermeable to ue gases and that offer lasting
resistance to mechanical stress, heat and the action of
the products of combustion and condensate
−It must be vertical, free of restrictions and contain bends
of no more than 45°
−It must be suitable for the specic operating conditions
of the boiler and must be CE marked (EN1856-1, EN1443)
−It must be of adequate dimensions to ensure draught
and venting properties suitable for the needs of the
boiler (EN13384-1)
−It must have adequate external insulation to prevent
condensation and the cooling of ue gases
−the stack must have a dedicated condensate drain system
at the bottom.
9 The diameter of the stack must never be smaller than that of
the ue pipe from the boiler.
9 In conguration B23, the stack must guarantee the minimum
draught specied by applicable technical standards,
assuming zero pressure at the boiler's ue gas exhaust.
2.10.2 Connection to the stack
The boiler must be connected to the stack using rigid ue
pipes that are resistant to heat, condensate and mechanical
stress. All joins must be sealed and the nished ue must be
insulated. Only use materials that are suitable for this purpose,
e.g. stainless steel.
The near-horizontal section of ue pipe must have a slope of at
least 5° towards the boiler and must also be properly insulated.
In long near-horizontal sections of ue pipe (L>1 m), install a
condensate drain system near the boiler exhaust (as shown in
the gure) to drain off any condensate forming in this section
of ue.
The diameter of the stack must always be greater than that of the
ue pipe from the boiler's exhaust tting. To change direction,
use a T section with an inspection cap to permit easy access
for cleaning inside the pipe. After cleaning, always make sure
that inspection caps are replaced tightly and that their seals are
undamaged and efcient.
9 Flue pipes must maintain a distance of at least 500 mm
from ammable or heat sensitive construction materials.
9 Joins must be sealed with materials that are resistant to acid
condensate and to the high temperatures of the boiler's
ue gases.
9 When installing ue pipes, always bear in mind the direction
of the ue gases and of possible condensate ows.
9 Inadequate or badly dimensioned stacks and ues can
increase combustion noise, cause condensation problems
and affect combustion parameters.
9 Uninsulated ues are potentially dangerous and can cause
burns.

19
INSTALLATION
2.11 System lling and emptying
INSIEME EVO 25 boilers require a lling pipe connected to the
central heating circuit return pipe.
Turn the mains power switch OFF and turn the control panel
function selector to (0) before lling or draining the system.
2.11.1 Water quality requirements
The manufacturer recommends the use of water as heat transfer
uid for the central heating system. A chemical treatment system
must be provided for this water.
The heat transfer uid (water) for the central heating circuit must
conform to the quality parameters given in the following table:
MINIMUM REFERENCE VALUES
pH 6-8
Electrical conductivity less than 200 μS/cm (25°C)
Chlorine ions less than 50 ppm
Sulphuric acid ions less than 50 ppm
Total iron less than 0.3 ppm
Alkalinity M less than 50 ppm
Total hardness less than 35°F
Sulphur ions none
Ammonia ions none
Silicon ions less than 30 ppm
If the hardness of the water exceeds the value specied in the
table, it is mandatory to install a water softening system.
9 Excessive water softening (leading to a total hardness <
15°F) can cause corrosion in metal parts (pipes and boiler
components). Keep the electrical conductivity of the water
under 200 μS/cm.
0 Do not top up the central heating circuit on a frequent
or continuous basis as this can damage the boiler’s heat
exchanger. The use of automatic topping up systems should
be avoided for this reason.
2.11.2 Filling
RI
−Make sure that the boiler’s drain cock (1) is closed before
you start lling the system.
1
−Open the central heating circuit shut-off cocks and slowly
ll the system until the pressure gauge reads out a value
of 1.5 bar (cold).
20 100
4
40 60 80
321
0
0120
RI
−Close the central heating circuit shut-off cocks.
NOTE The system is de-aerated automatically through the
automatic vent valve.
The water drain hose from the vent valve must be
connected to a proper collection system.

20
INSTALLATION
2.11.3 Emptying
Before draining the boiler:
−Turn the mains power switch OFF and turn the control
panel function selector to (0).
−Close the water supply shut-off cocks;
−To empty the boiler, connect a rubber hose (Øint=12mm)
to the hose union on the boiler's drain cock (1), then
open the cock.
1
2