Robur Caldaia 35 Tech Service manual

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Installation, use and maintenance manual
Caldaia 35 Tech
Outdoor condensing boiler

This Installation, use and maintenance manual has been drawn up and printed by Robur S.p.A.; whole or partial
reproduction of this Installation, use and maintenance manual is prohibited.
The original is led at Robur S.p.A.
Any use of this Installation, use and maintenance manual other than for personal consultation must be previously
authorised by Robur S.p.A.
The rights of those who have legitimately led the registered trademarks contained within this publication are not
aected.
With the aim of continuously improving the quality of its products, Robur S.p.A. reserves the right to modify the
data and contents of this Installation, use and maintenance manual without prior notice.
Revision: B
Code: D-LBR749EN
DISPOSAL
The appliance and all its accessories must be disposed of separately in accordance with the regulations in force.
Use of the WEEE symbol (Waste Electrical and Electronic Equipment) indicates that this product cannot be disposed of as household waste.
Proper disposal of this product helps to prevent potential negative consequences for the environment and human health.

Installation, use and maintenance manual – Caldaia 35 Tech 3
INDEX OF CONTENTS
I Introduction............................................................................. p.4
I.1 Recipients .......................................................................... p.4
II Symbols and denitions............................................... p.4
II.1 Key to symbols................................................................. p.4
II.2 Terms and denitions.................................................... p.4
III Warnings...................................................................................... p.4
III.1 General and safety warnings...................................... p.4
III.2 Conformity ........................................................................ p.5
III.3 Exclusions of liability and warranty.......................... p.6
1 Features and technical data...................................... p.7
1.1 Features.............................................................................. p.7
1.2 Dimensions ....................................................................... p.7
1.3 Components..................................................................... p.8
1.4 Technical characteristics............................................... p.9
1.5 Electrical wiring diagram ........................................... p.11
2 Transport and positioning........................................ p.12
2.1 Warnings.......................................................................... p.12
2.2 Handling........................................................................... p.12
2.3 Minimum clearance distances.................................. p.12
3 Heating engineer............................................................... p.12
3.1 Warnings.......................................................................... p.12
3.2 Boiler installation .......................................................... p.12
3.3 Hydraulic connections ................................................ p.13
3.4 Combustion products exhaust ................................ p.15
3.5 Pump antifreeze and anti-lock function............... p.16
3.6 Fuel gas supply .............................................................. p.17
4 Electrical installer.............................................................. p.18
4.1 Warnings.......................................................................... p.18
4.2 Electrical power supply............................................... p.18
4.3 Control device................................................................ p.19
4.4 Control through optional OCDS006 remote
control - recommended solution............................ p.19
4.5 Positioning the control system................................ p.19
4.6 Operation via centralised external request......... p.20
4.7 Operation with external temperature probe
(optional).......................................................................... p.20
5 First start-up .......................................................................... p.20
5.1 Preliminary checks........................................................ p.20
5.2 How to access the boiler............................................ p.20
5.3 Electronic board parameters setting..................... p.21
5.4 Combustion parameters check................................ p.24
5.5 Gas changeover............................................................. p.25
5.6 Commissioning.............................................................. p.25
5.7 Switching o................................................................... p.26
5.8 Prolonged periods of inactivity ............................... p.26
6 Normal operation.............................................................. p.26
6.1 Warnings.......................................................................... p.27
6.2 Preliminary checks........................................................ p.27
6.3 Operation without remote control......................... p.27
6.4 Remote control operation (optional)..................... p.28
Info menu display......................................................... p.28
7 Maintenance.......................................................................... p.28
7.1 Hydraulic boiler emptying......................................... p.28
8 Diagnostics.............................................................................. p.29
8.1 System pressure restore ............................................. p.29
8.2 Error codes....................................................................... p.29
9 Appendices.............................................................................. p.31
9.1 Product che................................................................... p.31

Introduction
4
I
I INTRODUCTION
Manual
This Manual is an integral part of the Caldaia 35 Tech
unit and must be handed to the end user together with
the appliance.
I.1 RECIPIENTS
This Manual is intended for:
▶ End user, for appropriate and safe use of the appliance.
▶ Qualied installer, for correct appliance installation.
▶ Planner, for specic information on the appliance.
II SYMBOLS AND DEFINITIONS
II.1 KEY TO SYMBOLS
DANGER
WARNING
NOTE
PROCEDURE
REFERENCE (to other document)
II.2 TERMS AND DEFINITIONS
Appliance/Unit = equivalent terms, both used to refer to the
Caldaia 35 Tech.
Boiler/External module = equivalent terms, both used to des-
ignate the part of the appliance to be installed outside the room
to be heated.
TAC = Technical Assistance Centre authorised by Robur.
Remote control = optional control device with chronothermo-
stat function.
External request = generic control device (e.g. thermostat, tim-
er or any other system) equipped with a voltage-free NO contact
and used as control to start/stop the Caldaia 35 Tech unit.
First start-up = appliance commissioning operation which may
only and exclusively be carried out by a TAC.
III WARNINGS
III.1 GENERAL AND SAFETY WARNINGS
Installer's qualications
Installation must exclusively be performed by a quali-
ed rm and by skilled personnel, with specic knowl-
edge on heating, electrical systems and gas appliances,
in compliance with the laws in force in the Country of
installation.
Declaration of conformity
Upon completing installation, the installing rm shall
issue to the owner/client the appliance's workmanlike
conformity declaration, according to national/local reg-
ulations in force and the manufacturer's instructions/
provisions.
Packing
Packing items (plastic bags, polystyrene foam, nails, etc.)
must be kept out of the reach of children, as they are po-
tentially dangerous.
Misuse
The appliance must only be used for the purposes for
which it has been designed. Any other use is deemed
hazardous. Incorrect use may aect operation, duration
and safety of the appliance. Adhere to the manufactur-
er's instructions.
Use of the appliance by children
The device can be used by children over 8 years old,
and by people with reduced physical, sensory or mental
capabilities, or lack of experience or knowledge, only if
they are under surveillance or after they have received
instructions regarding safe use of the appliance and un-
derstanding the dangers inherent in it. Children should
not play with the appliance. Cleaning and maintenance
that must be performed by the user must not be per-
formed by unsupervised children.
Hazardous situations
Do not start the appliance in hazardous conditions, such
as: gas smell, problems with the plumbing/electrical/gas
system, parts of the appliance under water or damaged,
malfunctioning, disabling or bypassing control and safe-
ty devices.
In case of danger, request intervention by qualied per-
sonnel.
In case of danger, switch o the electrical power and gas
supplies only if this can be done in total safety.

Warnings
Installation, use and maintenance manual – Caldaia 35 Tech 5
III
Do not entrust children, persons with physical, sensory
or mental disabilities or persons with poor knowledge
and experience with use of the appliance.
Gas component tightness
Before performing any operation on gas ducting compo-
nents, close the gas valve.
Upon completing any procedure, perform the tightness
test according to regulations in force.
Gas smell
If you smell gas:
Do not use electrical devices such as telephones, mul-
timeters or other equipment that may cause sparks next
to the appliance.
Shut o the gas supply by turning the valve o.
Disconnect electrical power supply by means of the
external isolation switch in the power supply electrical
panel.
Use a telephone away from the appliance to ask for inter-
vention from qualied personnel.
Poisoning
Ensure the ue gas ducts are tightness and compliant
with the regulations in force.
Upon completing any procedure, ensure components
are tightness.
Moving parts
The appliance contains moving parts.
Do not remove guards during operation, and in any case
prior to disconnecting the power supply.
Burn hazard
The appliance contains very hot parts.
Do not open the appliance and do not touch internal
components before the appliance has cooled down.
Do not touch the ue gas exhaust before it has cooled
down.
Electrocution hazard
Disconnect the electrical power supply before any oper-
ation on appliance components.
For electrical connections exclusively use compliant
components and according to the specications provid-
ed by the manufacturer.
Ensure the appliance cannot be accidentally switched
back on.
Earthing
Electrical safety depends on eective earthing system,
correctly connected to the appliance and installed ac-
cording to the regulations in force.
Acid ue gas condensate
Discharge the acid condensate of combustion ue gas in
compliance with current exhaust regulations.
Switching the appliance o
Disconnecting the power supply while the appliance
is running may cause permanent damage to internal
components.
Except in the event of danger, do not disconnect the
power supply to switch o the appliance, but always and
exclusively act through the provided control device.
In the event of failure
Operations on internal components and repairs may
exclusively be carried out by a TAC, using only original
parts.
In the event of failure of the appliance and/or breakage
of any component, do not attempt to repair and/or re-
store and immediately contact the TAC.
Routine maintenance
Proper maintenance assures the eciency and good op-
eration of the appliance over time.
Maintenance must be performed according to the man-
ufacturer's instructions (see Chapter 7 p. 28 ) and in
compliance with current regulations.
Appliance maintenance and repairs may only be entrust-
ed to rms legally authorised to work on gas appliances
and systems.
Enter into a maintenance contract with an authorised
specialised rm for routine maintenance and for servic-
ing in case of need.
Use only original parts.
Decommissioning and disposal
If the appliance is to be disposed of, contact the manu-
facturer for its disposal.
Keep the Manual
This Installation, use and maintenance manual must al-
ways accompany the appliance and must be handed to
the new owner or installer in the event of sale or removal.
III.2 CONFORMITY
EU Directives and standards
The appliance is certied in accordance with European regula-
tion GAR 426/2016/EU and meet the essential requirements of
the following Directives:
▶ Eciency Directive 92/42/EEC and subsequent modica-
tions and additions.
▶ 2016/426/EU "Gas Appliances Regulation" as amended and
added.
▶ 2014/30/EC "Electromagnetic Compatibility Directive" as
amended and added.
▶ 2014/35/EC "LowVoltage Directive" as amended and added.
▶ 2006/42/EC "Machine Directive" as amended and added.
Furthermore, they comply with the requirements of the follow-
ing standards:
▶ EN 677 Specic requirements for condensing boilers with
nominal heat input up to 70 kW.
▶ EN 483 Type C boilers of nominal heat input not exceeding
70 kW.
▶ EN 15502 Gas-red central heating boilers.

Warnings
6
III
Other applicable provisions and standards
The design, installation, operation and maintenance of the sys-
tems shall be carried out in compliance with current applicable
regulations, depending on the Country and location, and in ac-
cordance with the manufacturer's instructions. In particular, reg-
ulations regarding the following shall be complied with:
▶ Gas systems and equipment.
▶ Electrical systems and equipment.
▶ Heating systems employing condensing boilers.
▶ Environmental protection and combustion products ex-
haust.
▶ Fire safety and prevention.
▶ Any other applicable law, standard and regulation.
III.3 EXCLUSIONS OF LIABILITY AND
WARRANTY
Any contractual or extra-contractual liability of the
manufacturer for any damage caused by incorrect in-
stallation and/or improper use and/or failure to comply
with regulations and with the manufacturer's directions/
instructions shall be disclaimed.
In particular, the warranty on the appliance may be ren-
dered void by the following conditions:
Incorrect installation.
Misuse.
Failure to comply with the manufacturer's indications on
installation, use and maintenance.
Alteration or modication of the product or any part
thereof.
Extreme operational conditions or however outside of
the operational ranges set forth by the manufacturer.
Damages caused by external agents such as salts, chlo-
rine, sulphur or other chemical substances contained in
the installation water or present in the air of the instal-
lation site.
Abnormal actions transmitted to the appliance by the
plant or installation (mechanical stresses, pressure, vi-
brations, thermal expansion, electrical surges...).
Accidental damages or due to force majeure.

Features and technical data
Installation, use and maintenance manual – Caldaia 35 Tech 7
1
1 FEATURES AND TECHNICAL DATA
1.1 FEATURES
Operation
The Caldaia 35 Tech units have been designed and built to meet
the needs of space heating.These boilers (external modules) can
also be installed outdoors.
The boiler casing is made of ABS, and is approved to resist
weathering with particular regard to the action of UV rays.
The appliance operation will be controlled by an external re-
quest (chronothermostat, room thermostat or another opera-
tion request) or by the remote control to be installed inside the
heated room.
When the heating service is requested, detected by the external
request or by the remote control, the electronic board starts the
circulation pump, the blower and then the burner.
When the burner starts up, the ame detector checks that the
burner has ignited; in the event of a lack of ame, the electronic
control unit stops the appliance and indicates the block. Reset-
ting is manual.
In the event of abnormal overheating of the delivery, the boiler
is switched o. The limit thermostat has manual reset.
Mechanical and thermo-hydraulic components
▶ Integrated spiral single tube stainless steel heat exchanger.
▶ Premix modulating burner with 1:9 ratio.
▶ Automatic air vent valve.
▶ High eciency modulating water pump.
▶ System drain tap.
▶ Water temperature probe.
▶ Condensate drain siphon.
Control and safety devices
▶ Flue safety thermal fuse.
▶ 3 bar safety valve.
▶ Gas solenoid valve.
▶ Safety thermostat.
▶ Expansion tank.
▶ Water dierential pressure switch.
1.2 DIMENSIONS
Figure1.1Boiler dimensions
R Water inlet connection Ø 3/4" M
G Gas connection Ø 3/4" M
F System lling connection Ø 1/2"
A Water outlet connection Ø 3/4" M
B Flue gas outlet Ø 80 mm
140
162
710
420
370
53 148 80 102 37
110
R G F A
B

Features and technical data
8
1
1.3 COMPONENTS
Figure1.2Boiler internal front view
1 SYstem lling tap
2 Heat exchanger
3 Burner unit
4 Flame detector
5 Heating return probe
6 Blower
7 Safety valve
8 Air vent valve
9 Modulating circulator
10 Gas valve
11 System drain tap
12 Heating delivery probe
13 Safety thermostat
14 Ignition electrode
15 Expansion tank
16 Ignition transformer
17 Air intake pipe
18 Venturi
19 Water pressure switch
20 Condensate drain siphon
2
3
4
5
7
9
10
11
12
13
14
15
17
16
18
19
20
1
8
6
Figure1.3Hydraulic plan of boiler inside
R Heating return
G Gas inlet
SC Condensate drain
F Cold water inlet
A Heating delivery
1 Flue safety thermal fuse
2 Heat exchanger
3 Burner unit
4 Blower
5 Gas valve
6 Air vent valve
7 Modulating circulator
8 Safety valve
9 System drain tap
10 Heating delivery probe
11 Safety thermostat
12 Expansion tank
13 Air intake pipe
14 Venturi
15 Water pressure switch
16 Condensate drain siphon
17 Bypass
18 SYstem lling tap
R
F A
G
1
2
3
4
6
7
8
9
6
10
11
12
13
14
15
17
18
sc
5
16

Features and technical data
Installation, use and maintenance manual – Caldaia 35 Tech 9
1
1.4 TECHNICAL CHARACTERISTICS
Table1.1Technical characteristics
Caldaia 35 Tech
Heating mode
seasonal space heating energy eciency class (ErP) A
Heat input nominal (1013 mbar - 15 °C) (1) kW 34,0
minimum (1) kW 4,1
Operating point 80/60 Nominal heat input eective power kW 33,4
eciency % 98,1
Operating point 50/30 Nominal heat input eciency % 106,4
Operating point Tr = 30 °C Heat input 30% eciency % 108,6
Operating point Tr = 47 °C Heat input 30% eciency % 102,1
Heat loss
to jacket in operation % 0,25
to ue in operation % 2,40
in o mode % 0,03
Hot water delivery temperature maximum °C 80
Ambient air temperature (dry
bulb)
maximum °C 40
minimum °C -10
eciency class ****
Electrical specications
Power supply
voltage V 230
type - SINGLE PHASE
frequency Hz 50
Electrical power absorption nominal kW 0,08
Degree of protection IP - X5D
Installation data
Gas consumption
G20 natural gas (nominal) m³/h 3,60
G25 (nominal) m³/h 4,18
G25.3 (nominal) m³/h 4,09
G30 (nominal) kg/h 2,68
G31 (nominal) kg/h 2,64
Water tting type - M
thread “ 3/4
Gas connection type - M
thread “ 3/4
Flue gas exhaust diameter (Ø) mm 80
residual head Pa 91
CO2percentage in fumes
Nominal heat input
G20 % 9,3
G25 % 9,2
G25.3 % 9,2
G30 % 11,3
G31 % 10,4
Minimal heat input
G20 % 9,0
G25 % 8,9
G25.3 % 8,9
G30 % 10,8
G31 % 9,9
Flue temperature Nominal heat input G20 °C 69,4
Fumes ow rate Nominal heat input G20 kg/h 54
Minimal heat input G20 kg/h 7
CO emission ppm 75,0
NOxemission class - 6
Circulating pump data Residual pressure head at nominal ow rate boiler only m w.c. 1,5
nominal ow at the maximum available head l/h 1400
type of installation - B23P, B33
maximum equivalent length of exhaust duct m 15
maximum water pressure in operation bar 3,0
maximum ow ue condensate l/h 3,4
Water content inside the apparatus l 6
expansion tank volume l 8
Dimensions
width mm 420
depth mm 370
height mm 787
Weight in operation kg 44
(1) Relative to NCV (net caloric value).

Features and technical data
10
1
1.4.1 Circulating pump characteristic curves
Figure1.4Circulating pump characteristic curves
0 0,4 0,8 1,2 1,6 2,0 2,4
0 0,1 0,2 0,3 0,4 0,5 0,6 0,7
0 2 4 6 8
0
1
2
3
4
5
6
7
8
0
10
20
30
40
50
70
60
80
0 0,4 0,8 1,2 1,6 2,0 2,4
0
10
20
30
40
15%
25%
5%
p/kPa
H/m
P
1
/W
Q/m³/ h
Q/l/s
Q/Igpm
Q/m³/ h
max.
max.
35%
45%
55%
65%
75%
85%

Features and technical data
Installation, use and maintenance manual – Caldaia 35 Tech 11
1
1.5 ELECTRICAL WIRING DIAGRAM
Figure1.5Boiler electrical connections diagram
ER Flame detector
EA Ignition electrode
PM Modulating circulator
VG Gas valve
Tra Ignition transformer
TS Safety thermostat
Pacq Water pressure switch
SR Heating delivery probe
EV Blower
TF Flue gas thermofuse
SRi Heating return probe
MP Control panel terminal block
Se Connector for optional outdoor temperature
probe
Ta Connector for optional room thermostat
CS Standby contact
L Line
N Neutral
ne Black
ce Light blue
ma Brown
ar Orange
gi Yellow
bi White
gr Grey
ma
ce
ma
ce
ma
ce
ma
gi
bi
gr
EV
ce
ma
ce
ma
EA
VG
Tra
ce
ma
ER
TS
TF
SR
ar ar
ce
ma ma
ce
ne ne
220 V
50 Hz
MP
Pacq
11
10
98
7
12
13
14
15
16
17
M12 M9 M7 M5
M2
M4
M8
M10
M15
M16
1
2
3
4
57
61
60
59
58
44 43 42 41 40
39 38
37 36 35 34 33 32
31 30
29 28
27 26
62
63
64
65
66
67
68
51
52
53
54
55
56
56
M13
M14
LNSeSe
TaTa
+24V
HS
PWM
GND
PM
SRi
ma
ce
CS
ar
ar

Transport and positioning
12
2
2 TRANSPORT AND POSITIONING
2.1 WARNINGS
Damage from transport or installation
The manufacturer shall not be liable for any damage dur-
ing appliance transport and installation.
On-site inspection
Upon arrival at the site, ensure there is no transport dam-
age on packing or boiler panels.
After removing the packing materials, ensure the appli-
ance is intact and complete.
Packing
Only remove the packing after placing the appliance on
site.
Do not leave parts of the packing within the reach of
children (plastic, polystyrene, nails...) since they are po-
tentially dangerous.
Weight
The lifting equipment must be suitable for the load.
Do not stand under suspended loads.
2.2 HANDLING
Handling and lifting
▶ Always handle the appliance in its packing, as delivered by
the factory.
▶ Comply with safety regulations at the installation site.
In the event of handling with forklift or pallet truck,
comply with the handling instructions shown on the
packing.
2.3 MINIMUM CLEARANCE DISTANCES
Keep the appliance away from combustible or am-
mable materials or components, in compliance with ap-
plicable regulations.
In order to allow periodic maintenance of the boiler, the
installation must take place outside, respecting the dis-
tances indicated in Figure 2.1 p.12 and in any case at a
height from the oor of no more than 3 metres.
Figure2.1Clearances
A 250 mm
B min 300 mm, max 3000 mm
X 60 mm
Y 60 mm
H 1000 mm
H
X
A
B
Y
3 HEATING ENGINEER
3.1 WARNINGS
3.1.1 General warnings
Read the warnings in Chapter III.1 p. 4 , providing im-
portant information on regulations and on safety.
Compliance with installation standards
Installation must comply with applicable regulations in
force, based on the installation Country and site, in mat-
ters of safety, design, implementation and maintenance
of:
heating systems
gas systems
ue gas exhaust
ue gas condensate discharge
Installation must also comply with the manufacturer's
provisions.
3.2 BOILER INSTALLATION
1. Fix the mounting jig of the external module to the instal-
lation wall, matching, if already present, the Ø 80 mm hole
for the passage of water pipes and electrical cables with the
shape of the relative hole (Ø 80 mm) indicated on the jig.
At this point, in correspondence with the relative shapes of
the holes indicated on the jig, trace the following points for
drilling on the wall: 3 xing holes (Ø 10 mm) and 1 lower hole
(moved to the right) Ø 10 mm.
2. Remove the mounting jig from the wall and drill the holes
marked out in the previous point: for the 3 upper holes (Ø

Heating engineer
Installation, use and maintenance manual – Caldaia 35 Tech 13
3
10 mm) for xing the support bracket and the one for the
frame of the external module, a depth of 90 mm is sucient;
the hole (Ø 80 mm) must be drilled for the entire thickness
of the wall.
3. Insert a plastic pipe through the wall into the hole (Ø 80
mm), cut to size.
4. Position the support bracket of the external module in corre-
spondence with the upper holes made (Ø 10 mm, depth 90
mm) and secure it with the supplied wall plugs.
5. Lift the boiler and hook it to the support bracket.
6. Secure the boiler permanently to the wall, fastening the rear
panel by means of the third wall plug supplied.
3.3 HYDRAULIC CONNECTIONS
The hydraulic installer must make the hydraulic connection cir-
cuit to the heating system.
To facilitate mounting, the boiler is equipped with a kit of hy-
dronic ttings (Figure 3.1 p.13 ) to be connected to the boiler
after removing the tting cover (Figure 5.1 p.21 ).
Figure3.1Hydronic tting kit
A Delivery
R Return
A
R
The installer must provide for the construction of a suitably sized
hydraulic connection circuit, taking into account:
A. of the following indications:
Use pipes for heating/cooling systems, protected from
weathering and freezing, insulated for thermal disper-
sion.
Sizing of the pipes, according to the standard circulator,
must grant the nominal water ow required for the cor-
rect operation of the heating system.
B. of the following data:
nominal ow at the maximum available head = 1400 l/h
Residual pressure head at nominal ow rate = 1,5 m w.c.
3.3.1 System connections
Connect the water pipes between the boiler and the
system as follows:
1. After having removed the tting cover (Figure 5.1 p. 21 ),
connect the copper 90° ttings supplied to the hydraulic
connections of the boiler service plate, taking care to orient
them towards the wall hole (hole Ø 80 mm, made during the
installation phases of the boiler on the wall).
2. Connect the hydraulic hoses to the water delivery and return
connections (Figure 1.1 p. 7 ), interposing appropriate
gaskets on each connection and taking care to avoid the en-
try of foreign bodies.
3. Connect a hose connected to a system test pump to the sys-
tem lling tap (Figure 3.3 p. 14 ) on the boiler and ll the
hydraulic circuit with water; the air in the circuit and in the
pipes will be automatically vented by the venting device on
the boiler.
For the calculation of the total water content to be
loaded in the system it is necessary to add the water
content of the boiler (Table 1.1 p. 9 ) and of the distri-
bution terminals to the water content in the pipes.
In order to ensure correct operation of the unit and avoid
freezing of the water during the winter periods (with
possible damage to the unit and the system), it is nec-
essary to add antifreeze glycol to the water in a quantity
proportional to the minimum winter temperatures of
the installation site (see Table 3.1 p.13 ).
Table3.1% of glycol, correction factor for pressure drop
Low roughness pipes
(copper, stainless steel and plastic) Medium roughness pipes (black and galvanized steel)
% of antifreeze glycol Protection temperature (°C) Correction factor for pressure drop Correction factor for pressure drop
15% -5 1,08 1,06
20% -8 1,11 1,08
25% -12 1,15 1,10
30% -15 1,19 1,12
Connect the boiler safety drains (heating circuit safety
valve) to a drain funnel. The manufacturer is not respon-
sible for any damage due to the opening of the safety
valve in case of overpressure of the system.
3.3.2 System lling
Proceed with the lling of the system as follows.
1. Slightly loosen the cap of the jolly valve on the circulator to
release the air from the system (Figure 3.2 p.14 ).
2. Slightly loosen the cap of the jolly valve placed on the top of
the condensing block (Figure 3.4 p. 14 ) to release the air
from the top of the boiler.
3. Open the lling tap (Figure 3.3 p.14 ) and let out all the air.
4. Check with pressure gauge (Figure 3.3 p. 14 ) that system
pressure reaches 1,2 bar (Figure 3.5 p.14 ).
5. Open the automatic air purging valves on the system, if any,
and check the air purging process.
6. Make sure that the unit is energized.
7. Send an operating request to the unit for a few seconds.The
circulating pump will be immediately activated.
8. Remove the request before the burner is activated. The cir-
culating pump will continue to circulate the water for the
post-circulation time.
9. If, after the above operations, a decrease in system water
pressure is observed, open again the system lling valve

Heating engineer
14
3
until the system pressure reaches 1,2 bar.
10. Repeat steps 7, 8 and 9 until the pressure has stabilised (at
least 1,2 bar).
11. After the operation, make sure that the system lling tap
(Figure 3.3 p.14 ) is tightly closed.
Once the lling operation has been completed, re-
member to close the cap of the jolly valve on the circula-
tion pump, to avoid water leaks.
To start the circulation pump only, with the boiler pow-
ered, press the button (Figure 6.1 p. 26 ): the
symbol will appear on the display; after a few sec-
onds turn o the boiler by pressing the button
again (the symbol will appear on the display). The
circulation pump will remain in operation for a few min-
utes. Repeat the operation several times until the pres-
sure of the circuit remains unchanged.
The rst time the unit is switched on, an automatic
system venting cycle is activated (see note in Paragraph
5.6 p.25 ).
Figure3.2Cap of the jolly valve on ciculating pump
1 Cap of the jolly valve
1
Figure3.3Pressure gauge and system lling tap
M Pressure gauge
R System lling tap
R
M
Figure3.4Cap of the jolly valve on condensing block
Figure3.5Pressure gauge

Heating engineer
Installation, use and maintenance manual – Caldaia 35 Tech 15
3
3.3.2.1 System water characteristics
Responsibility of the user/operator/installer
The installer, operator and user must assure system wa-
ter quality (Table 3.2 p.15 ). Failure to comply with the
manufacturer's guidelines may aect operation, integri-
ty and life of the appliance, voiding the warranty.
In order to avoid any scale or deposits on the primary
exchanger, the water in the system must be treated in ac-
cordance with the applicable standards. This treatment
is absolutely essential in cases where there are frequent
episodes of water supply or partial or total emptying of
the system.
The hardness of the lling and top-up water brings a certain
amount of calcium into the system. This is attached to the hot
parts including the heat exchanger, thus creating pressure loss-
es and thermal insulation on the active parts. This can lead to
damage.
If the lling and top-up water of the system is outside the values
indicated below, it must be softened. Additives may also be add-
ed to keep the calcium in solution. Hardness should be checked
regularly and recorded.
If the above limits are exceeded, a water chemical treatment
must be carried out.
The choice of the type of treatment must be made according to
the characteristics of the water to be treated, the type of plant
and the limits of purity required.
Adhere to the chemical-physical parameters in Table 3.2 p.15
and the regulations on water treatment for residential and in-
dustrial heating systems.
Table3.2Chemical and physical parameters of water
Acidity 7 < pH < 8,5
Conductivity < 400 μS/cm (at 25°C)
Chlorides < 125 mg/l
Iron < 0,5 mg/l
Copper < 0,1 mg/l
3.3.3 Condensate drain siphon lling
When switching on for the rst time, the condensate siphon
must be lled to prevent the combustion gases from backow-
ing through the siphon.
It is advisable, after the rst few months of operation of the ap-
pliance, to clean the siphon, which collects also any deposits re-
sulting from the rst passage of the condensate inside the com-
ponents of the boiler. These deposits could cause the siphon
itself to malfunction.
For charging the siphon proceed as follows (Figure 3.6 p.15 ):
1. Unscrew screw P, remove the siphon and ll it with water to
the top point T.
2. Replace the siphon and fasten it with the screw P.
3. Connect the specically designed exible condensate drain
hose to a drainage system.
Figure3.6Condensate drain siphon
P Fastening screw
T Top point
T
P
3.4 COMBUSTION PRODUCTS EXHAUST
Installation types
For this type of boiler the ue gas exhaust conguration
B23P, B33 can be used.
3.4.1 Flue gas exhaust connection
▶ Ø 80 mm, on the upper side of the boiler (Figure 1.1 p.7 ).
The Caldaia 35 Tech is supplied with a anged socket, equipped
with a socket for ue gas analysis (detail PF in Figure 5.6 p.24 ),
which must be connected to the combustion chamber after hav-
ing interposed the silicone gasket, supplied, for the protection
against weathering.
After installing the anged socket, it is important to
check the correct positioning of the gasket G positioned
on the combustion chamber (Figure 3.7 p.15 ).
Incorrect positioning of the gasket G can compromise
the correct discharge of the ue gas outside and conse-
quently damage the appliance.
Figure3.7Correct gasket positioning
G Gasket
G
The combustion air is drawn from the outside of the casing by

Heating engineer
16
3
means of special louvres located in the lower part of the casing.
3.4.2 How to realize the ue gas exhaust
For the ue gas exhaust without a chimney, the special rainproof
terminal (code OTRM031) is available as an option.
It is not recommended to install the ue terminal near
the boiler if it is close to a wall.This condition could cause
condensation to form on the terminal and on the wall
that would fall on the boiler.
To avoid this type of problem, it is recommended to
take the ue terminal beyond the roof of the building
as shown in Figure 3.8 p. 16 or to carry out the ue
exhaust horizontally as shown in Figure 3.9 p. 16 , re-
specting the indications given in Paragraph 3.4.3 p.16 .
Figure3.8Roof vertical ue gas exhaust
Figure3.9Horizontal ue gas exhaust
3.4.3 Possible ue
In case of extension of the duct, follow the instructions below:
▶ Use ducts and terminals (Ø 80 mm) suitable for forced draft
condensing appliances.
▶ For vertical ducts longer than 1,5 m, a curve and aTee (Figure
3.10 p. 16 ) for condensate collection and drainage must
be provided. The condensate must then be evacuated in ac-
cordance with the regulations in force, at the same time as
that coming from inside the boiler.
Figure3.10Flue gas condensate discharge
> 300 mm
The connection of the discharge to the sewerage system
must be made at atmospheric pressure, i.e. by dripping
into a siphoned container connected to the sewerage
system.
Maximum exhaust length
▶ Pipe Ø 80 mm: 15 m
▶ Blower available head: 91 Pa
The maximum exhaust length (or equivalent linear length) is ob-
tained by adding the length of the linear duct to the equivalent
length of each additional curve.
The equivalent lengths of the curves are given in Table
3.3 p.16 .
Table3.3
Elbow Ø 80 mm
90° elbow 1,5 m
45° elbow 1,2 m
3.5 PUMP ANTIFREEZE AND ANTILOCK
FUNCTION
Antifreeze function
If the delivery temperature detected by the temperature probe
falls below +12 ºC (antifreeze temperature ON), the control
board starts the circulation pump and the ignition of the burner
at the minimum power.
When the delivery water temperature reaches +30 ºC (antifreeze
temperature OFF), the control board will switch the burner o.

Heating engineer
Installation, use and maintenance manual – Caldaia 35 Tech 17
3
Electrical and gas continuity
The antifreeze function is only eective if the power
and gas supplies are assured. Otherwise, antifreeze uid
might be required.
Pump anti-lock function
In order to prevent the circulation pump from locking, the
Caldaia 35 Tech is equipped with an anti-lock function which,
every 24 hours of inactivity, operates the circulation pump for
30 seconds.
Electrical continuity
The pump anti-lock function is only eective if the pow-
er supply is guaranteed.
3.6 FUEL GAS SUPPLY
Gas connection
▶ 3/4" M
on the bottom of the boiler (Figure 1.1 p.7 ).
▶ Install an anti-vibration connection between the appliance
and the gas piping.
Mandatory shut-o valve
▶ Provide a gas shut-o valve (manual) on the gas supply line,
next to the appliance, to isolate it when required.
▶ Perform connection in compliance with applicable regula-
tions.
Gas pipes sizing
The gas pipes must not cause excessive pressure drops and, con-
sequently, insucient gas pressure for the appliance.
Supply gas pressure
This appliance is equipped for a maximum gas supply
pressure of 50 mbar.
The appliance's gas supply pressure, both static and dynamic,
must comply with Table 3.4 p.17 , with tolerance ± 15%.
Non compliant gas pressure (Table 3.4 p. 17 ) may
damage the appliance and be hazardous.
Table3.4Gas network pressure
Product category Countries of destination Gas supply pressure [mbar]
G20 G25 G25.3 G30 G31
II2H3B/P
AL, AT, BG, CH, CY, CZ, DK, EE, FI, GR, HR, IT, LT, LV, MK, NO, RO, SE,
SI, SK, TR 20 30
AT, CH 20 50
HU 25 30
II2H3P
AL, BE, BG, CH, CZ, ES, FR, GB, GR, HR, IE, IT, LT, NL, LV, MK, PL, PT,
SI, SK, TR 20 37
AT, BE, CH, CZ, DE, ES, FR, GB, HU, NL, SK 20 50
AT, CZ, DE, NL, RO 20 30
II2ELL3B/P DE 20 20 50
II2Esi3P FR 20 25 37
II2E(R)3P BE 20 37
II2E(S)3P 20 37
II2E3P LU 20 50
II2E3B/P DE, PL, RO 20 30
II2L3B/P RO 20 30
II2L3P FR 25 37
RO 20 37
II2EK3P
NL
20 25 30
II2EK3B/P 20 25 30
I2EK 20 25
I2ELL DE 20 20
I2E(S) BE 20
I2E(R) 20
I2Esi FR 20 25
I2H
AL, AT, BG, CH, CY, CZ, DK, EE, ES, FI, GB, GR, HR, IE, IT, LT, LV, MK,
NO, PT, RO, SE, SI, SK, TR 20
FR 20
HU 25
I2L FR 25
RO 20
I2E DE, PL, RO 20
I3B/P
AL, AT, BG, BE, CY, CZ, DE, DK, EE, FI, FR, GB, GR, HR, HU, IT, LT, MT,
NL, NO, RO, SE, SI,TR 30
PL 37
AT, CH, DE, SK, CY, CZ 50
FR 50
The appliance gas supply pressure, both static and dynamic, must comply with the values in theTable, with a tolerance of ± 15%.

Electrical installer
18
4
Product category Countries of destination Gas supply pressure [mbar]
G20 G25 G25.3 G30 G31
I3P
AT, BE, CH, CZ, DE, ES, FR, GB, HU, IS, NL, SK 50
AL, BE, BG, CH, CZ, ES, FR, GB, GR, HR, IE, IT, LT, NL, LV, MK, PL, PT,
SI, SK, TR 37
AT, CZ, DE, NL, RO 30
The appliance gas supply pressure, both static and dynamic, must comply with the values in theTable, with a tolerance of ± 15%.
Before proceeding with the construction of the system, the in-
staller must:
▶ Check that the gas used corresponds to that for which the
appliance has been designed (see nameplate).
▶ Check that the ow rate of the gas meter is such as to ensure
the simultaneous use of all the devices connected to it.
Although it is normal for the inlet pressure to decrease
during the operation of the appliance, it is important to
check that there are no excessive uctuations in the inlet
pressure. In order to limit the extent of these variations, it
is necessary to appropriately dene the diameter of the
gas inlet pipe to be adopted based on the length and
pressure drop of the pipe itself, from the gas meter to
the boiler.
If uctuations in the gas distribution pressure happen,
it is advisable to insert a special pressure stabiliser up-
stream of the gas inlet to the boiler. In case of LPG
supply, all necessary precautions must be taken to avoid
freezing of the combustible gas in case of very low
external temperatures.
If it is necessary to change the type of gas supply to
the boiler, contact the TAC that will make the necessary
changes.
Under no circumstances shall the installer be authorised
to carry out such operations.
Vertical pipes and condensate
▶ Vertical gas pipes must be tted with siphon and discharge
of the condensate that may form inside the pipe.
▶ If necessary, insulate the piping.
LPG pressure reducers
With LPG the following must be installed:
▶ A rst stage pressure reducer, close to the liquid gas tank.
▶ A second stage pressure reducer, close to the appliance.
4 ELECTRICAL INSTALLER
Do not power and/or start the boiler before lling the
hydraulic system, as this may damage the internal hy-
draulic components.
4.1 WARNINGS
General warnings
Read the warnings in Chapter III.1 p. 4 , providing im-
portant information on regulations and on safety.
Compliance with installation standards
Installation must comply with applicable regulations in
force, based on the installation Country and site, in mat-
ters of safety, design, implementation and maintenance
of electrical systems.
Installation must also comply with the manufacturer's
provisions.
Live components
After placing the appliance in the nal position, and pri-
or to making electrical connections, ensure not to work
on live components.
Earthing
The appliance must be connected to an eective earth-
ing system, installed in compliance with regulations in
force.
It is forbidden to use gas pipes as earthing.
Cable segregation
Keep power cables physically separate from signal ones.
Do not use the power supply switch to turn the ap-
pliance on/o
Never use the external isolation switch to turn the appli-
ance on and o, since it may be damaged in the long run
(occasional blackouts are tolerated).
To switch the appliance on and o, use only the control
device provided for this purpose (remote control or ex-
ternal request).
4.2 ELECTRICAL POWER SUPPLY
The cables inside the boiler must be routed through the
P1 and P2 cable glands (Figure 4.2 p. 19 ). To do this,
make a hole in the cable gland, slightly smaller than the
cable, so that the air does not pass through.

Electrical installer
Installation, use and maintenance manual – Caldaia 35 Tech 19
4
How to connect the power supply
1. Remove the ABS casing, the tting cover and the front panel
(Paragraph 5.2 p.20 ).
2. Unscrew the two screws and remove the terminal block cov-
er plate (Figure 4.1 p.19 ).
3. Perform connections as shown in Figure 4.1 p.19 .
4. The ground wire to the terminal marked with the ground
symbol.
5. The neutral cable to the terminal marked with the letter N.
6. The line cable to the terminal marked with the letter L.
Figure4.1Electrical power supply
A Plate
B Terminal block
1 Neutral
2 Yellow/Green
3 Line
LNSeSe
A
TaTa
B
1
2
3
4.3 CONTROL DEVICE
To make the electrical connections of the room thermostat (TA)
or of the remote control (optional OCDS006) or of an external
request, proceed as follows (Figure 4.2 p.19 ).
1. Remove the bridge on the Ta-Ta contacts and then connect
the two non-polarized conductors on the Ta-Ta contacts.
2. After the operation, reassemble the plate, the front panel,
the tting cover and the ABS casing.
Figure4.2Cable gland position and remote control connection detail
to the external module
P1 - P2 Cable glands
A Plate
B Terminal block
CR Room thermostat or remote control (OCDS006)
P1 P2
LNSeSe
A
TaTa
BCR
4.4 CONTROL THROUGH OPTIONAL
OCDS006 REMOTE CONTROL 
RECOMMENDED SOLUTION
The use of the remote control allows you to adjust the opera-
tion of the boiler to the desired temperature, in the time pro-
gramming chosen, provides a series of information on the status
of operation and/or boiler lock and also allows the resetting of
some locks.
For the electrical connection of the remote control, follow the
instructions given in Paragraph 4.3 p.19 .
The remote control is electrically connected to the boiler
by means of two non-polarized conductors through
which it receives the power supply necessary for its op-
eration and carries out communication between the two
devices.
4.5 POSITIONING THE CONTROL SYSTEM
Install the chosen thermostat/control system according to the
following guidelines:
▶ At about 1,5 m from the oor, protected against air draughts,
direct exposure to sun rays and direct heat sources (lamps,
hot air ow from the unit itself, etc.).

First start-up
20
5
▶ If possible, do not place the control system on walls bor-
dering the outside, to avoid false temperature readings
and therefore aect system operation. If this is not possible,
shield the control system by placing a sheet of insulating
material (cork, polystyrene or other similar) between the
control system and the wall.
By following the above guidelines, unwanted starting
and stopping of the system can be avoided and optimal
comfort in the heated space can be guaranteed.
4.6 OPERATION VIA CENTRALISED
EXTERNAL REQUEST
The unit's operation can also be controlled by means of an ex-
ternal request.This request, activated for example by a program-
mable timer or another system, can be used for the centralised
activation or deactivation of several boilers.
For the electrical connection of the external request, follow the
instructions below:
1. Remove the ABS casing, the tting cover and the front panel
(Paragraph 5.2 p.20 ).
2. Access the CS terminal block on the left side of the control
panel (Figure 1.5 p.11 ).
3. Connect the external request to the terminal block.
4. After the operation, reassemble the plate, the front panel,
the tting cover and the ABS casing.
The terminals have open contacts from the factory
(active request). If the boiler is to be switched o, the
contact between the terminals must be closed. When
these are closed, the boiler will stop, while when they are
reopened, the boiler can be activated according to what
has been set on the other controls (room thermostat or
remote control).
In the case of centralized management of several boilers,
each request must be connected through the interposi-
tion of a relay.
For further information on the operation and use of
boilers in this mode, please contact the Robur technical
service.
4.7 OPERATION WITH EXTERNAL
TEMPERATURE PROBE OPTIONAL
It is possible to operate the boiler with a variable water ow tem-
perature depending on the outdoor temperature.
To do this, it is necessary to install an outdoor temperature
probe (available as OSND007 optional) and connect it to the SE
terminals of the boiler terminal block (Figure 1.5 p.11 ).
The outdoor temperature probe provides the temperature val-
ue of the outdoor air and according to this the electronic board
of the boiler will change the water supply temperature. The ex-
tent of the temperature correction depends on the temperature
control value Kd set (using the board parameter P16 - see Figure
5.4 p.23 ).
5 FIRST START-UP
First start-up entails checking/setting up the combus-
tion parameters and may exclusively be carried out by a
Robur TAC. NEITHER the user NOR the installation tech-
nician is authorised to perform such operations, under
penalty of voiding the warranty.
5.1 PRELIMINARY CHECKS
5.1.1 Preliminary checks for rst start-up
Upon completing installation, before contacting the TAC the in-
staller must check:
▶ Water, electrical and gas systems suitable for the required
capacities and equipped with all safety and control devices
required by the regulations in force.
▶ Absence of leaks in the water and gas systems.
▶ Type of gas for which the appliance is designed (natural gas
or LPG).
▶ Supply gas pressure complying with the values of Table
3.4 p.17 .
▶ Power supply mains complying with the appliance's rating
plate data.
▶ Appliance correctly installed, according to the manufactur-
er's instructions.
▶ System installed in a workmanlike manner, according to na-
tional and local regulations.
5.1.2 Abnormal or hazardous installation situations
Should any abnormal or hazardous installation situations be
found, theTAC shall not perform rst start-up and the appliance
shall not be commissioned.
These situations may be:
▶ Failed compliance with minimum clearances.
▶ Insucient distance from combustible or ammable mate-
rials.
▶ Conditions that do not warrant access and maintenance in
safety.
▶ Appliance switched on/o with the main switch, instead of
the provided control device.
▶ Appliance defects or faults caused during transport or instal-
lation.
▶ Gas smell.
▶ Non-compliant mains gas pressure.
▶ Non-compliant ue gas exhaust.
▶ All situations that may involve operation abnormalities or
are potentially hazardous.
5.1.3 Non-compliant system and corrective actions
Should the TAC nd any non conformities, the user/installer is
bound to perform any corrective procedures required by the
TAC.
After performing the remedial actions (the installer's responsi-
bility), if the TAC deems that safety and conformity conditions
are in place, rst start-up may be eected.
5.2 HOW TO ACCESSTHE BOILER
For all check and maintenance operations it is necessary to re-
move the front panel of the boiler as follows (Figure 5.1 p.21 ):
1. Remove the fastening screws 1 located to the side of the
casing ange, and pull it out as shown in Figure 5.1 p.21 .