Unical modulex 360 Installation and operating instructions

00332210-2nd edition-09/05
360 - 450
540 - 630
MODULEX
INSTALLATION, USE AND
MAINTENANCE
GB
MODULAR CONDENSING
BOILER






2
IMPORTANT
This INSTRUCTION MANUAL, which is an integral and indispensable part of the product, must be handed over to the user by the plumbers and
must be kept in a safe place for future reference.The manual must be handed over with the boiler should it be sold or transferred.
This boiler must be used for the purposes for which it has been designed. Any other use shall be considered incorrect and therefore
dangerous.
The boiler must be installed in compliance with applicable laws and standards and according to the manufacturer’s instructions given in this
manual.Incorrect installation may cause injury to persons and/or animals and damage to property.The manufacturer shall not be held liable for any
such injury and/or damage.
Damageand/or injury caused byincorrect installation or use and/or damage and/or injury due to non-observanceofthe manufacturer’sinstructions
shall relieve UNICAL from any and all contractual and extracontractual liability.
Before installing the boiler, check that the technical data corresponds to requirements for its correct use in the system.
Check that the boiler is intact and that it has not been damaged during transport and handling.Do not install equipment which is patently damaged
and/or faulty.
Do not obstruct the air suction and/or heat dissipation grates.
Only original accessories must be used for all boilers supplied with optionals or kits (including electrical ones).
Dispose of the packaging with care as all the materials can be recycled.The packaging must therefore be sent to specific waste management
sites.
Keep the packaging out of the reach of children as it may represent a choking and suffocation hazard.
In the event of failure and/or faulty functioning, switch off the boiler. Do not attempt to make repairs: contact qualified technicians.
Original parts must be used for all repairs to the boiler.
Non-observance of the above requirement may jeopardize the safety of the boilers and expose people, animals and property to danger.
To guarantee efficiency and correct functioning of the equipment it is legally binding to service the boilers once a year according to
the schedule indicated in the relative section of this manual.
In the event of long periods of inactivity of the boiler, disconnect it from the power mains and close the gas tap (Warning! In this case the boiler’s
electronic anti-freeze function will not be operative).
Should there be a risk of freezing, add anti-freeze: it is not advisable to empty the system as this may result in damage; use specific anti-freeze
products suitable for multi-metal heating systems.
N.B.
For boilers which use gaseous fuel, if you smell gas:
- do not turn on or off electrical switches and do not turn on electrical appliances;
- do not ignite flames and do not smoke;
- close the main gas tap;
- opendoors and windows;
- contact a Service Centre, qualified installer or the gas supply company.
Never use flames to detect gas leaks.
WARNING
This boiler has been built for installation in the country indicated on the technical data plate: installation in any other country may be a source
of danger for people, animals and property.
Read the warranty conditions and clauses on the warranty certificate attached to the boiler with care.

3
DATA PLATE
1 = P.I.N. code
2 = Boiler type (only for condensing boiler)
3 = (S.N°) Serial Nr.
4 = Manufacture Date
5 = Model
6 = Appliance type
7 = Elettrical supply
8 = Maximum absorbed power - Insulation
protection
9 = (Pn) Nominal Output
10 = (Pcond) Condensing Nominal Output
(only for condensing boiler)
11 = (D) Specific flow rate EN 625
12 = (Qn) Nominal heat input
13 = (Qnw) Nominal heat input for D.H.W.
system if there are different out puts
between the C.H.and D.H.W.circuits
14 = (NOx) NOx Class
15 = (PMS) Max pressure C.H. system
16 = (T max) MaxTemperature C.H.system
17 = (PMW) Max pressure D.H.W.system
18 = (T max)Temperature D.H.W.system
19 = Adjusted for gas type X
20 = Country of destination, Gas category,
Supply pressure
21 = Side for national brand
®
2H
2E
3+
3B/P
3P
G20
G20
G30/G31
G30 - 31
G31
20 - 25
20
28-30/37
30 - 50
37 - 50
mbar
mbar
mbar
mbar
mbar
IT ES IE
PT GR
TR HR
CZ SK
HU
SI
GB
CN RU RO
LV EE LT
II 2H3+
II 2H3+
II 2H3B/P
II 2H3P
II 2HS 3B/P
II 2E3P
II 2H3P
I 2H
I 2H
20 ; 28-30/37 mbar
20 ; 28-30/37 mbar
20 ; 50 mbar
18 ; 50 mbar
25 ; 30 mbar
20 ; 50 mbar
20 ; 37 mbar
20 mbar
20 mbar
/
1
2
345
678
9
12
15
17
19
20
18
16
10
13
11
14
21

4
1
2
3
TECHNICALFEATURES
ANDDIMENSIONS........................................................... pag. 6
1.1 Technical Features .................................................................. pag. 6
1.2 Dimensions.............................................................................. pag. 7
1.3 Technical Data and Main Components .................................... pag. 9
1.4 SideView................................................................................. pag. 10
INSTRUCTIONS FOR INSTALLERS ................. pag. 11
2.1 Instructions for installation...................................................... pag. 11
2.2 Installation ............................................................................... pag. 11
2.2.1 Packing ....................................................................... pag. 11
2.2.2 Boiler Location inside a Heat Power Plant ................. pag. 13
2.2.3 BoilerConnection ....................................................... pag. 13
2.2.4 Connection to Chimney .............................................. pag. 13
2.2.5 Notes on Condensate Drain ....................................... pag. 14
2.3 Types of Heating Systems ...................................................... pag. 15
2.3.1 C.H.System Air Vent.................................................. pag. 16
2.3.2 Boiler and System Filling-up & Draining .................... pag. 16
2.3.3 Max AllowableWorking Pressure............................... pag. 17
2.3.4 Safety Valve ............................................................... pag. 17
2.3.5 Gas Mains .................................................................. pag. 17
2.3.6 Hydraulic Compensator or Open Manifold ................. pag. 17
2.3.7 Filter ........................................................................... pag. 18
2.3.8 BallValves .................................................................. pag. 18
2.3.9 FeedingWaterQuality ................................................ pag. 18
2.3.10 Boiler Antifrost Protection .......................................... pag. 18
2.3.11 Min.WaterFlow Rate.................................................. pag. 19
2.4 Boiler Operation....................................................................... pag. 19
2.4.1 GeneralDescription .................................................... pag. 20
2.4.2 IgnitionSequence....................................................... pag. 21
2.4.3 SupplementaryBoard ................................................. pag. 22
2.4.4 DomesticHotWater(DHW) Mode Operation ............. pag. 23
2.5 Boiler Operation in case of technical intervention .................. pag. 23
2.6 Electric Connections ............................................................... pag. 24
2.6.1 PowerSupply .............................................................. pag. 25
2.6.1 WiringDiagram ........................................................... pag. 25
2.6.2 Electric Connection to Ignition PCB........................... pag. 26
2.6.3 Electric Connection to the Room Thermostat ............ pag. 26
2.6.4 DHWStorageTank ..................................................... pag. 27
MODULAR BOILER DRIVE (MBD)
OPERATION.......................................................................... pag. 28
3.1 General Description ................................................................. pag. 28
3.2 Operation and display instructions .......................................... pag. 28
3.2.1 “Mode”Key.............................................................. pag. 29
3.2.2 “Step”Key ............................................................... pag. 29
3.2.3 “+ / -“ Key................................................................ pag. 29
3.2.4 “Store”Key .............................................................. pag. 29
3.2.5 ServiceCode .......................................................... pag. 29
3.2.6 Programming Access Procedure ........................... pag. 30
3.2.7 “Stand-by”Key ........................................................ pag. 32

5
4
3.2.8 “Parameter”Mode ................................................... pag. 32
3.2.8.1 Installerand User programmable Operation
Parameters............................................... pag. 32
3.2.8.2 InstallerprogrammableOperation
Parameters by previously entering
the service code ...................................... pag. 33
3.2.9 “Data”Mode ............................................................ pag. 34
3.2.9.1 Installerand User programmable
parameters ............................................... pag. 34
3.2.9.2 Installerprogrammableparameters
by previously entering the
service code............................................. pag. 34
3.2.10 “Test”Mode ............................................................. pag. 35
3.2.11 “OperationTime”Mode ........................................... pag. 35
3.3 HeatingModeOperation.......................................................... pag. 36
3.3.1 Heating Mode Operation by RoomThermostat............. pag. 36
3.3.2 Heating Mode Operation by Outer Sensor.................... pag. 36
3.3.3 Heating Mode Operation by Outer Compensator .......... pag. 37
3.4 DHWMode Operation. ............................................................. pag. 37
3.4.1 DHW Mode Operation by StorageTank NTC Sensor ... pag. 37
3.4.2 DHW Mode Operation by StorageTankThermostat ..... pag. 37
3.5 Burner Pressure AdjustmentTest ........................................... pag. 38
ERRORS ................................................................. pag. 39
4.1 Blank Display ................................................................. pag. 39
4.2 The Boiler doesn’t fulfill the DHW Production Request. ......... pag. 39
4.3 Ignition Anomalies ................................................................. pag. 39
4.4 Block Errors ................................................................. pag. 39
4.5 ErrorCodes ................................................................. pag. 40
4.5.1 Error Codes by Alarm.................................................... pag. 40
4.5.2 Error Codes related to local temperatures .................... pag. 40
4.5.3 Error Codes related to gas pressure, MBD,
AM-4 and AM-5 ............................................................ pag. 41
4.5.4 Error Codes related to global temperatures .................. pag. 41
MAINTENANCE .................................................. pag. 42
5.1 Main Features .................................................. pag. 42
5.2 Siphon Cleaning .................................................. pag. 42
5

6
GENERAL DESCRIPTION
1
1.1 - TECHNICAL /
FEATURES
- MODULEX is a compact, gas fired,
Low NOx, condensing boiler, made
up by one sectional boiler body (so
called
heat module ), set to operate
separately or in cascade.
This heat module consists of two or
more thermal elements (from 4 to 7),
which cannot be separated from
each other, being under the same
protectingcasing.These thermal ele-
ments are connected to a single
smoke exhaust manifold and are
controlled by a single microproces-
sor which manages completely the
temperatures from the point of view,
both operational and safety.
- If, for instance, one of the thermal
elements whose the boiler is com-
posed, goes out of order, the other
thermal elements continue to sup-
ply their output. It is nearly impossi-
ble the boiler go completely out of
order.
- MODULEX has been examined ac-
cording the following European di-
rectives:
- (GAD) Gas Appliances Directive
No. 90/396 CEE
- (BED) Boiler Efficiency Directive
No. 92/42 CEE
by CERTIGAZ, under the No.
1312BP4012, fortype B23 operation,
i.e. the boiler can be connected to a
traditional natural draught chimney,
andfor operation in category I2H (G20
–20mbar).
It also conforms to the following Eu-
ropean directives:
- EMC (Electro Magnetic Compatibi-
lity) Directive No.89/336 CEE
- LVD (LowVoltage Directive)
No. 73/23 CEE
- Machines Directive
No. 89/392 CEE
- The boiler body, made by sections
of cast aluminium/magnesium/sili-
cium alloy, is conceived to recover
the sensible and the latent heat of
the combustion gases, thus al-
lowing to reach an efficiency of
109% on the N.C.V.
- Each thermal element, composed of
a combustion chamber with burner,
modulating fan with control pressu-
re switch, gas valve, ignition devi-
ce, flame control, NTC sensor for lo-
cal temperature control and safety
thermostat, can deliver an output
between a maximum of 90 kW and a
minimum of 22 kW.
- Each single boiler is equipped with
NTC sensors for global temperatu-
re control on the flow and return ma-
nifolds.
- Total premix modulating burner
equipped with metallic sponge ra-
diation burner.
Premix in the pre-combustion cham-
ber. Automatic no return diaphragm
for separation from combustion
chamber.
- Combustion air suction/feeding sy-
stem from the boiler house
- Possible cascade installation of 2 or
more MODULEX
- Heating Operation: setting of instan-
taneous output by a main micropro-
cessor, with a comparison parame-
ters pre-setting between the reque-
sted temperature (or calculated by
the outer compensator) and the glo-
bal flow temperature.
- Logic of operation:
A) Output sharing on as many mo-
dules as possible at min. load (down
to 22 kW) for the max.efficiency.
B) Automatic operation hour split-
ting-up system for each module to
guarantee the best homogeneous
use.
C) DHW production by a priority sen-
sor which, thanks to the dedicated
electronic board, drives a special
loading pump or a 3-way diverting
valve for the preparation of a stora-
ge tank with the possibility of pre-
setting the D.H.W. circuit output, up
tomaximum360kW.
D) Output check of each module for
any calibration and/or assistance by
secret access code.
- Control panel with alphanumeric di-
splay, programming keys, reset and
hydrometer.
- Displays:globalflow/returntempera-
ture,DHW temperature,external tem-
perature.
- Adjustments: flow temperature, fan
speed,max/min. output percentage.
- Access to all testing/programming
parametersofeach module:operation
test, operation time, boiler anti-frost
protection from 7°C, pump’s anti-
blocking system.
- Integral easily removable panel set
(painted steel panels).
- Condensate collecting tank equip-
ped with drain siphon and stain-
less steel smoke chamber.
- Built-in air vent.
- Weights and dimensions are limi-
ted (see table at par. 1.2).
4
5
6
7
360
450
540
630
60
75 l/h
90 l/h
105 l/h
l/h

7
1.2 - DIMENSION
fig. 1-a
REAR VIEW
UPPER VIEW
L.H. SIDE VIEW FRONT VIEW
MODULEX 360
®
1243
576
STOR
E
MO
DE
RES
ET
STE
P
920
S
BA
C
206
171
1372
666
232
474
974 398
R
M
G
474 446
Øi D
110
124
H
MODULEX
Dimension
No. of Modules
Height mm
Width ''L'' net mm
Width with packaging mm
Depth ''C'' mm
Depth ''A'' mm
Depth ''B'' mm
Depth with packaging mm
Net weight kg
Gross weight kg
Connections
Gas mm
C.H. system Flow M mm
C.H. system Return R mm
Chimney connection ''D'' mm
Chimney width ''H'' mm
Condensate drain diameter mm
360
4
1372
920
1020
1530
985
390
1200
430
496
DN50 PN 10/16
DN80 PN 10/16
DN80 PN 10/16
250
615
40
ATTENTION
CHIMNEY
CONNECTION
INDIFFERENT
POSITION FROM THE
ONE SHOWN ARE
NOT ALLOWED.

8
fig. 1-b
MODULEX 450 - 540 - 630
®
1243
576
ST
ORE
MOD
E
R
ES
ET
STEP
920
(D) 1520
(E) 425
F
474
124
232 666
G
=
206
171
974 398
R
M
G
1372
==
350
S
Øi D
ATTENTION
CHIMNEY
CONNECTION
INDIFFERENT
POSITION FROM THE
ONE SHOWN ARE
NOT ALLOWED.
540
6
1372
920
1020
1520
425
1256
1380
1700
620
700
DN50 PN 10/16
DN100 PN 10/16
DN100 PN 10/16
300
720
40
630
7
1372
920
1020
1520
425
1390
1514
1840
680
778
DN50 PN 10/16
DN100 PN 10/16
DN100 PN 10/16
300
855
40
450
5
1372
920
1020
1520
445
1120
1320
1340
510
584
DN50 PN 10/16
DN80 PN 10/16
DN80 PN 10/16
250
615
40
H
600
175 425
110
124
MODULEX
Dimension
No. of Modules
Height mm
Width ''L'' net mm
Width with packaging mm
Width ''D'' mm
Width ''E'' mm
Depth ''F'' mm
Depth with packaging mm
Net weight kg
Gross weight kg
Connections
Gas mm
C.H. system Flow M mm
C.H. system Return R mm
Chimney connection ''D'' mm
Chimney width ''H'' mm
Condensate drain diameter mm
REAR VIEW
UPPER VIEW
R.H. SIDE VIEW FRONT VIEW

9
1.3 - TECHNICAL DATA
The Technical data plate is placed under the front jacket next to the control
panel.
BOILER TYPE MODULEX
Nominal Heat Input on P.C.I
Qn kW
Minimum Heat Input on P.C.I . Qmin kW
Nominal Output (Tr 60 / Tm 80 °C) Pn kW
Minimum Output (Tr 60 / Tm 80 °C) Pn min kW
Nominal Output (Tr 30 / Tm 50 °C) Pcond kW
Minimum Output (Tr 30 / Tm 50 °C) Pcond min kW
Efficiency at max. output (Tr 60 / Tm 80°C) %
Efficiency at min. output (Tr 60 / Tm 80°C) %
Efficiency at max. output (Tr 30 / Tm 50°C) %
Efficiency at min. output (Tr 30 /Tm 50°C) %
Efficiency at 30 % at part load (Tm 50°C) %
Efficiency at 30 % at part load (Tr 30°C) %
Efficiency Class acc. to Directive 92/42 CEE
Efficiency Class acc. to Directive 92/42 CEE (100%) %
Efficiency Class acc. to Directive 92/42 CEE (30%) %
Combustion efficiency at nominal load %
Combustion efficiency at part load %
Stand-by losses (Q min.) %
Stand-by losses (Q nom.) %
Flue gas temperature (min) °C
Flue gas temperature (max) °C
Flue gas mass flow rate (min) kg/h
Flue gas mass flow rate (max) kg/h
Excess of air λ%
CO2 (min) %
CO2 (max) %
NOX(value according EN 297/A3 + EN 483) mg/kWh
NOXclass
Flue losses with burner in operation (min.) %
Flue losses with burner in operation (max) %
Flue losses with burner off %
Min. water flow rate in CH circuit (∆T 20°C) l/h
Minimum pressure in CH circuit bar
Maximum pressure in CH circuit bar
DHW specific flow rate l
Gas Consumption Natural gas G 20 (20 mbar) Qn m3/h
Gas Consumption Natural gas G 20 (20 mbar) Qmin m3/h
Max. available pressure at the chimney base Pa
Condensate production kg/h
Emissions
CO with 0% of O2in the flue system ppm
NOxwith 0% of O2in the flue system ppm
Sound level dBA
Electrical data A
Voltage / Frequency V/Hz
Fuse on main supply A (F)
Max / Min absorbed power W
Insulation degree IP
Standby Consumption W
360
360
22
353,9
21,3
377,60
23,80
98,30
96,82
104,89
108,18
102,0
109,2
4
98,10
96,65
97,52
97,86
1,0
n.r
42
50
36,6
583,0
24,25
8,9
9,2
62
5
2,48
2,14
0,2
16237
0,5
6
73
38,06
-
2,33
-
100
22,7÷60
<35
<35
<50
230 / 50
4
540/41
40
10
450
450
22
442,5
21,3
472,0
23,80
98,33
96,82
104,89
108,18
102,0
109,2
4
98,29
96,94
97,52
97,86
1,0
n.r
42
50
36,6
728,7
24,25
8,9
9,2
62
5
2,48
2,14
0,2
20296
0,5
6
88
47,58
-
2,33
-
100
28,3÷75
<35
<35
<50
230 / 50
4
675/41
40
10
540
540
22
531,8
21,3
566,4
23,80
98,48
96,82
104,89
108,18
102,0
109,2
4
98,45
97,18
97,52
97,86
1,0
n.r
42
50
36,6
874,4
24,25
8,9
9,2
62
5
2,48
2,14
0,2
24355
0,5
6
103
57,10
-
2,33
-
100
34÷90
<35
<35
<50
230 / 50
4
810/41
40
10
630
630
22
621,3
21,3
660,8
23,80
98,62
96,82
104,89
108,18
102,0
109,2
4
98,59
97,38
97,52
97,86
1,0
n.r
42
50
36,6
1020,2
24,25
8,9
9,2
62
5
2,48
2,14
0,2
28414
0,5
6
118
66,61
-
2,33
-
100
39,7÷105
<35
<35
<50
230 / 50
4
945/41
40
10

10
fig. 2
1.4 - SIDE VIEW WITH MAIN COMPONENTS
2.1 - COMPOSITION OF THE
SUPPLY
- Boilerbody made ofsectionsof alumi-
nium/magnesium/siliciumalloy (5to 8)
- Premix stainless-steel burner (4 to 7)
- Premixing chamber (8 to 14) with bu-
ilt-in non return valve
- Modulating fan (4 to 7) with air pres-
sure switch control
-Gas valve (2 for each module – from 8
to 14) with separated flame control
device SATRONIC (from 4 to 7)
- NTCsensorsforlocal temperaturecon-
trolon eachboilersection (5to8)
- NTC sensor for global flow manifold
temperature
- NTC sensor for global return mani-
fold temperature
- High Limit thermostat on each boiler
section (5 to 8)
- Automatic air vent on the flow mani-
fold
- Boiler draining/filling tap on return
manifold
- Minimum gas pressure switch on gas
manifold
- Condensate collecting tray
- Plastic pipe (1m) and fittings for con-
densate evacuation Ø40
- Smokechamberterminal,withflue soc-
ket:
Ø 250 mm for models 360 and 450
Ø 300 mm for models 540 and 630
- Integral painted steel casing
- Modulation and control PCB (MBD)
with PC interface
- AM-4 PCB for DHW production and
outdoortemperature sensor
- Supplementary PCB type AM-5 (1 x
mod. 360; 2 x mod. 450 and mod. 540;
3 x mod. 630)
- Electronic card for interface
- Outdoor sensor (into the smoke cham-
ber)
150
FAN
GAS VALVE
GAS PIPE
BURNER
ALUMINIUM/
SILICON HEAT
EXCHANGER
CONDENSATE
DRAIN
SIPHON
CONDENSATE
COLLECTING
TRAY-
SMOKE
MANIFOLD
FILLING-UP
ELBOW
C.H. RETURN
C.H. FLOW
Min. Depth 100 mm
BOILER FRAME

11
fig. 3
2.2 - INSTALLATION
2
2.1 - INSTRUCTIONSFORIN-
STALLATION
TheMODULEXboilerisforeseenforthe
I2H gas category and shall be installed
in compliance with the latest regulations
or rules in force.
IINSTRUCTIONS FOR
INSTALLERS
2.2.1 - PACKING
The MODULEX boiler is delivered into a
strong carton box, complete of pallet (in
order to easily transport the boiler up to
the nearest point of installation place. The
procedures for unloading the boiler are
shown into the figure 3.
Removebothstrapsandfinallythe card-
board box from above, making sure the
product is intact.The packing elements
(cardboard box, straps, plastic bags,
etc…) shall not be left to children’s
hand since they may be dangerous.
For the pallet removal is necessary to lift
the boiler:it’s necessary to use a jib cra-
ne (like shown into the figure 3), in order
to avoid of damage the pressure
switches, gas valves or electric cables.
- Remove the jacket and prepare the
slingwiththebands“A” (fig.3)bytaking
careoflet the bands pass internally of
flow, return and gas manifolds.
- Bind the bends to the jib; during this
step be particularly careful.
Inside the packing,
on the rear part of the boiler, for Mo-
dulex 360 – 450
on the front part of the boiler, for Mo-
dulex 540 – 630
you can find the smoke chamber, con-
taining:
- a plastic bag containing:
• 3 gaskets (1 rectangular between
condensate tray and flue terminal, 1
square between flue socket base and
flue terminal and 1 for flue socket Ø
250 or Ø 300 mm according to the
model
•2bends +1Teepiece+ 1plastic plug,
Ø 40 mm for condensate drain.
• the screws necessary for fixing
- A plate for the jacket closing, only for
models540-630
- The outdoor sensor
- The siphon pipe for condensate drain
on the L.H. side of the boiler:
- the R.H. side panel connected to the
L.H. side one by a thermoretractable
film.
A
BC
DIMENSIONS
modulex 360 1650 1200 1020
modulex 450 1650 1550 1020
modulex 540 1650 1700 1020
modulex 630 1650 1840 1020
ABC
on the boiler top:
- a plastic bag containing:
•This instruction manual
•Warranty certificate
• Hydraulic certificate

12
fig. 4
12
3
4
PALLET REMOVAL
BOILER UNLOADING AND PACKAGE REMOVAL
A
B

13
2.2.4.1 - MATERIALS FOR FLUE
PIPES
As material can be used the stainless
steel AISI 316 L or AISI 316 Ti, with a
minimumwall thickness of0.4 mm, or the
aluminium,withaminimumwall thickness
of 1.5 mm, or the PVDF (Polyvinildi-
methylfluorure),orthe PPS(Simple trans-
parent polypropylene), certified for this
use.Other materials and thicknessesare
alsoadmitted, providedthey guaranteeat
least equivalent caracteristics.
In case of tubing of an existing chimney
theflue pipe has to beofaluminium (min.
thickeness of 1.5 mm) or of stainless
steel (min. thickness of 0,4 mm) and its
connections have to be water proof.
2.2.2 - BOILER LOCATION INSIDE A
BOILER HOUSE
Specialattentionshall bepaid tolocalreg-
ulationsandlaws aboutboiler housesand
particularly to the obligation of keeping
minimum clearances and empty space
aroundthe boiler.The installationshallbe
in compliance with all latest regulations
andlawsaboutboilerhouses,installations
of heating and hot-water systems, venti-
lation, chimneys capable of evacuating
the flue gases of condensing boilers and
anyother applicable requirement.
When selecting the position for the
installation of the boiler it has to be
considered that, for the cleaning and
washing operations of the boiler
body, one of the boiler sides must be
accessible for the removal of a spe-
cial baffle placed under the aluminum
sections.
The boiler can be put on a flat and suffi-
ciently strong base with the same di
mensions as the boiler ones and at le-
ast 100mm high (see fig. 5), in order to
assemblethe condensate drain siphon.
An alternative to this base may be a
100 mm deep well next to the boiler as
siphon housing (see fig. 2). After instal-
lationtheboiler shall be
perfectly horizontal and stable, to redu-
ce any possible vibrations or noises.
2.2.3 - BOILER CONNECTION
The boiler Modulex leaves the factory pre-
disposed for the hydraulic and gas con-
nection on the back side of the boiler. The
smoke outlet is placed on the back side
2.2.4 - CONNECTION TO THE
CHIMNEY
ATTENTION:
BEFORE ASSEMBLING THE CHIM-
NEY DUCT IT’S ABSOLUTELY NE-
CESSARY TO SET A SUPPORT UN-
DER THE SMOKE CHAMBER TERMI-
NAL
Into a condensing boiler, the smokes re-
ach a very low temperature (Max 84°C).
So, it’s necessary that the chimney is
perfectlyimpermeable tocondensation of
combustionproducts and built withmate-
rials corrosion resistant.
The various spigot joints have to be well
sealed and endowed with provided for
gaskets, so that to prevent the conden-
sation spillage and the air entry.
For the chimney dimensioning, diameter
and height, it is necessary to make refe-
rencetothenationalandlocalregulations.
Inorder toavoid, duringthe operation,the
iceformation, the temperature ofthe insi-
de wall in every point of the system for
the combustion products evacuation, for
all of its length, doesn't have to be lower
than0°C.
For operation in condensing conditions
withthe outdoor temperature ofproject, it
will be therefore necessary the realiza-
tion of a system of confluent condensa-
tion drain, according to the installation
conditions, in the collection box of the
boileror separated by it.
of the boiler for MODULEX 360; it's pla-
ced on the R.H. side of the boiler for MO-
DULEX 450 - 540 - 630.
For the smoke chamber fixing, use the
4
5
6
7
450
540
630
360 250
250
300
300
screws and gaskets included into the in-
struction bag, and a cross screwdriver at
least 300 mm of length.

14
2.2.5 NOTES ON CONDENSATE
DRAIN
Avoid the condensate stagnation inside
the combustion products evacuation
system, (for this reason the evacuation
duct must have an inclination toward the
drain of at least 30 mm/m) except the
liquid column, inside the condensate
siphon (which needs to be filled with
water after installation: its minimum
height, when all the fans are in opera-
tion, must be at least 25 mm).
In order to avoid ice formation while the
boiler is operating, which can cause the
stop of the boiler, the whole condensate
evacuation system has to be well insu-
lated.Itis forbidden to evacuate the con-
densate through a gutter: risk of ice for-
mationand corrosion.
The condensate, before being evacua-
ted to the sewer , has to be neutralised,
neutralization which can be obtained by
mixing the drain water coming from
washing machines, dish washing ma-
chines, etc., which normally have a
basic pH. The connection to the sewer
will be through a visible drain. Given
the high acidity degree (pH 3 to 5) only
plastic materials can be used for the
condensate evacuation pipes. Moreo-
ver it must be dimensioned and cons-
tructed so as to allow the correct out-
flow of drains preventing any bottleneck
and any leakage.
fig. 5
* Min. height of the condensate column,
with all fans operating at max. speed,
requested by the EN standards.
** Min. height of the condensate column,
with all fans operating at max. speed. In
the case it is not possible to create a 100
mm basement, install the boiler on the
floor and foresee a min. 100 mm well to
lodge the siphon (see fig. 2).
2.2.6 - WATERTREATMENT
If the installation needs a water treat-
ment the following conditions are to be
respected:
- the pH, for boilers with aluminium
alloy body, must always be within
6.5 and 8;
2.2.6.1 - REPLACEMENT OF AN EXI-
STING BOILER BY A MODU-
LEX
In case of installation of a MODULEX on
an old C.H. system we recommend to
purge and to rinse properly the whole
system before connecting the new boiler.
To avoid misunderstandings it is sug-
- all precautions will be taken to avoid
the formation and localisation of oxy-
gen in the water of C.H. systems. For
this reason it will be necessary that
inthe C.H. systems using floorradiant
heating, the plastic pipes used are
impermeable to the oxygen;
- in case of utilisation of anti-frost so-
lutions, their compatibility with alu-
minium alloy and other components
of the C.H. system has to ascertai-
ned.
gested to interpose between the boiler
and the system, a plate heat exchanger.
On the contrary, in case of installation of a
MODULEX on a new system we recom-
mend to make a simple water rinse of the
whole system and to fit aY filter on the re-
turn pipe to the boiler, equipped with gate
valves.
BOILER HOUSE
FLOOR
150
150
INITIAL SIPHON
FILLING-UP PLUG The upper part of the drain
pipe shall not be higher
than the tray bottom.

15
Fig. 6.1 Heating system with one group of radiators.
2.3 - EXAMPLES OF
HEATING SYSTEMS
Fig. 6.2 Installation of a boiler with a mixing bottle and connection to a heating circuit with DHW production (storage tank output< or = boiler
output).
Fig. 6.3 Heating system with mixing bottle and flow temperature control by an outer compensator. More radiator groups are
controlled by a dedicated outer compensator.The heating curve of the boiler outer compensator has to be adjusted at 5 K above the
temperature of the radiator group working at the highest temperature.
111213
®
1243
576
STOR
E
MODE
RESE
T
STEP
161718
Return
Flow
Filter Boiler pump
See fig. 16
Mixing bottle
Heating Circuit
See fig. 16
D.H.W. Circuit
The following system figures are to illus-
trate some, but not all types of heating systems.
Filter Boiler pump
Return
Flow
111213
Mixing bottle
See fig. 16
Heating circuit
®
1243
576
STORE
MODE
R
ES
ET
STEP
Heating system
pump
111213
®
1243
576
STORE
MODE
RESET
STEP
Return
Flow
Filter Boiler pump
See fig. 16
Mixing bottle
Heating Circuit Heating Circuit Heating Circuit

16
2.3.1 - VENTING OF THE C.H. SY-
STEM
An effective air vent shall be foreseen
in the highest point of the system. Inside
2.3.2 - BOILER AND HEATING
SYSTEM FILLING-UP &
DRAINING
For filling-up the system a filling tap has
tobe foreseen on the systemreturn pipe.
The filling-up can also be made through
the draining tap on the boiler return
manifold.
Inboththe cases, an approved hydraulic
disconnection system has to be fitted.
Before connecting the boiler, carefully
rinse out the whole system by running
water.
Theboiler is equipped with its own drain-
ing tap (see fig. 2 for its position).
Never use such a tap to drain the sys-
tem, since the system dirt could gather
in the boiler and compromise its opera-
tion.The system itself shall be equipped
with its own draining tap, whose size de-
pendsonthesystemcapacity.Theappli-
cation of a filter on the return pipe to the
boileris advisable.
the boiler, there is an automatic air vent
on the flow manifold (see fig. 2). This air vent is foreseen for the boiler, not for the whole system.
Fig. 6.4 D.H.W. storage tank with loading pump installed on the secondary circuit, in parallel with the heating circuit.
Note: The Pr pump (heating pump) shall be off while the storage tank pump is running. In this case, the second digit of
parameter A shall be set to 2 (three-way valve).
For the connection of a boiler pump on the primary circuit or of a storage tank loading pump or a three-way valve, convenient
information can be found in the following table, which indicates the terminals supplied with 230 V in the different hypothesis.
The terminals 11 –13 will be supplied on tension 230 V in the case the pump after running is activated.
111213
®
1243
576
STOR
E
MODE
R
ES
ET
STEP
161718
See fig. 16
Return
Flow
Filter Boiler pump
See fig. 16
Mixing bottle
Heating Circuit
Heating
system pump
No return
valve
D.H.W. Circuit
Is there any heating demand?
YES/ NO YES / NO YES / NO YES NO
Is there any D.H.W. demand?
YES NO YES NO NO
D.H.W. priority system
configuration depending on 2
figure of “A Parameter”
(see paragraph 3.2.8.2)
nd
230 V - 50 Hz tension
is present at
terminals 16 - 18
parameter A = x 0 YES NO YES YES NO *
parameter A = x 1 YES NO NO YES NO *
parameter A = x 2 NO YES YES YES NO *
2
nd
figure
2
nd
figure
2
nd
figure
230 V - 50 Hz tension
is present at
terminals 11 - 13

17
2.3.3 - MAX ALLOWABLE WORKING
PRESSURE
The boiler max allowable working pres-
sure is 6 bar, while the min. one is 0,8
bar.
The boiler does not have any special
protection device against water lack,
2.3.4 - SAFETY PRESSURE RELIEF
VALVE (not supplied)
A safety valve dimensioned for the sys-
tem capacity and in compliance with
localregulations inforce shallbeinstalled
2.3.5 - GAS MAINS
Due to the presence of a min. gas pres-
sure switch, the gas main diameter shall
be calculated carefully.Even though the
since this function is carried out by the
safety thermostats of the modules with
timeliness. However, the installation of
amin. pressure switch aswell as its elec-
tric connection are foreseen (1/4” con-
on the flow pipe (within 500 mm from the
boiler).
2.3.6 - HYDRAULIC COMPENSATOR
OR OPEN MANIFOLD
For the correct operation of the boiler,
the use of an hydraulic compensator is
advisable because it guarantees:
- separationand gathering of circuit dirt
- best air venting
- hydraulic de-coupling of the two
hydraulic circulation circuits.
nection on the return manifold and elec-
trical in series connection on the min.
gas pressure switch terminals).
gas valves have their own filter,
UNICAL suggests one further filter easy
to be checked, to be installed on the
gas pipe supply.
fig. 7
BOILER
CIRCUIT HEATING
SYSTEM
CIRCUIT
D
1/2’’
KVKR
HR
g
abc
h
e
HV
1/2’’
1/2’’
1/2’’
g
C.H. FLOW
F
I
L
T
E
R
C.H. RETURN
C.H. FLOW
TABLE FOR THE RECOMMENDED
DIMENSION OF THE HYDRAULIC
COMPENSATOR
20.000
30.000
50.000
100.000
150.000
200.000
200
250
300
400
500
600
360 kW
360 - 450
450 Over
kW
- 540 - 630 kW
> 630 kW
100
125
150
200
250
300
100
125
150
200
250
300
200
200
250
250
300
300
1.000
1.000
1.000
1.500
1.500
1.800
300
300
300
300
400
400
150
150
150
200
300
300
1.650
1.650
1.700
2.250
2.500
2.800
200
200
200
200
200
200

18
2.3.7 - FILTER
UNICAL suggests the installation of aY
filter with two gate valves on the return
pipe so that it can be cleaned if neces-
sary. Such filter shall protect the boiler
2.3.8 - BALLVALVES
Unical suggests the installation of ball
gate valves on the system flow/return
pipes. In this case the boiler, if neces-
sary, can be disconnected or drained,
without having to drain the whole sys-
2.3.9 - FEEDING WATER QUALITY
- The system and reinstatement
water chemical-physical features
are fundamental for the boiler cor-
rect operation and safety.
- Among the inconveniences cau-
sed by feeding water low quali-
ties the most frequent and serious
one is the scale deposit on heat
exchange surfaces.
- Less frequent but not less serious
is the water side corrosion of all
heating circuits surfaces.
- It is known that calcareous scales
reduce heat exchange due to the-
ir low heat conductivity, so that
even few mm-thick scales may
cause very dangerous localised
overheating.
- Water treatment is advisable in the
following cases:
A) high hardness of the available
water (> 20°f)
B) very large heating systems
C) high quantities of reinstatement
water due to leakages or mainte-
nance works
- The use of an inhibitor is advisa-
ble to treat feeding waters and to
protect heating systems against
calcareous scales, corrosion and
microbiologic growth. In case of
freezing as well, the use of an anti-
frost together with the inhibitor is
advisable.
- Qualified companies can provide
boiler de-scaling.
tem. A closed expansion vessel, proper-
ly dimensioned and equipped with its
safety valve, shall be fitted between the
gate valves and the boiler.
from the heating system dirt. Its regular
cleaning has to be foreseen.
WARNING!
Never intercept safety devices, such
as safety valve and expansion ves-
sel.
- Any system needs water re-filling
because of evaporation, small or
substantial leakages and mainte-
nance. It is then necessary to cal-
culate the water quantity reque-
sted to avoid new inconveniences
due to untreated water.
To this purpose, the installation of
a water flow-meter is advisable on
reinstatement pipe.
2.3.10- BOILER ANTIFROST
PROTECTION
Should the flow temperature (measured
at global flow temperature NTC) de-
crease under 7°C, the system pump is
set up. Should temperature ulteriorly
decrease (under 3°C), all modules shall
start at min. output until the return tem-
perature reaches 10°C. Such protection
device is exclusively for the boiler. For
theprotection ofthewhole system,a sec-
ond anti-frost thermostat is necessary to
switch on the heating system pump.

19
2.3.11 - MINIMUMWATER FLOW RATE
A minimum water flow rate, as shown in
thetable on the right, is to beguaranteed
through the boiler at any time.
RICIRCULATION PUMP
The recirculation pump shall have a
manometric head able to assure the
water flow rate as per the diagram of fig.
8.
Pumps shall be calculated by install-
ers or technical engineers according
to boiler and system parameters.
fig. 8
The boiler consists of mutually connect-
ed combustion chambers; each of them
has its own burner, fan with air pres-
sure switch for control, two gas valves
withignitionand ionisation device.
Each group of these components is
calledthermal element.
Max.outputof athermalelementis90kW.
So,a 630 kW boiler consists of 7 thermal
elements.
Each thermal element has its own tem-
peraturesensor NTC - NegativeTemper-
ature Coefficient - called local NTC,
which locally checks the flow tempera-
2.4 - BOILER OPERATION tureof each thermal element.
The flow temperature at the boiler outlet
and the return temperature at the boiler
inlet are controlled by global NTC tem-
peraturesensors(seefig.2).
In case of more heat request by heating
orDHW systems,theboiler starts upand
waterwillbeheatedbyanaluminiumboil-
er body.Then the boiler pump sends wa-
ter to the mixing bottle and from here to
the radiators, according to the heating
system choosen.
The combustion air is supplied by fans
and taken in from the boiler room. The
combustion air is then pushed into the
pre-combustion chamber through a dia-
phragm. Beyond the diaphragm, the air
mixes with gas and such mixture pass-
ing through the non-return valve is sent
tothe burner.Then,onleavingtheburner
surface, the air/gas mixture ignites elec-
tricallyand the resulting combustion gas-
es, after being transported (and cooled)
through finned tubes, enter the conden-
sate collecting manifold and then are
evacuated through the chimney.
The water side resistance curve of the
boiler is shown in fig. 8.
The pump is not an integral part of the
boiler.
0
0,5
1
1,5
2
2,5
3
3,5
4
4,5
5
5,5
6
6,5
7
7,5
8
02,5 57,5 10 12,5 15 17,5
20 22,5 25 27,5 30 32,5 35 37,5 40 42,5 45 47,5 50 52,5 55
PRESSURE LOSSES
(mH O)
2
360
450 540
630
WATER FLOW m³/h
WATER SIDE
PRESSURE LOSSES
kW output 360 450 540 630
30,96 38,70 46,44 54,18
20,64 25,80 30,96 36,12
15,48 19,35 23,22 27,09
It's recommended to choose a circu-
lator with the rate and discharge head
around 2/3 of its charactestic curve.

20
2.4.1 - GENERAL DESCRIPTION
When there is an heat request from a
room thermostat or an outer compensa-
tor, the Modular Boiler Drive (MBD) cal-
culates the necessary output according
to the difference between the set tempe-
rature (or the temperature calculated by
the outer compensator) and the global
flowtemperature.The numberof thermal
elements (each thermal element repre-
sents a maximum output of 90 kW) x
100% determines the maximum output
expressed in %.
Whentheoutputhasbeendetermined,the
boilerpump (notsupplied byUnical) isset
up and the fan of one thermal element is
set in motion at starting speed.The gas
valve opens and ignition is to occur with-
in 5 sec. When the ionisation electrode
detects the flame, the thermal element
starts operating.
Subsequentlyother thermalelements are
likely to start in the same way.One of the
operation principles for this boiler is let-
ting as many burners as possible oper-
ate simultaneously at minimum load to
reach the maximum efficiency.
Forexample, ifa4 thermalelement boiler
isrequested to operate at its max output,
this shall be 400% i.e. :
90 kW x 4 thermal elements =
360 kW = 400%.
If it is requested to operate at 200% out-
put, thanks to the output sharing system
on the highest number of thermal ele-
ments,each thermal elementwill operate
at50% output i.e. :
200% : 4 thermal elements = 50%
equal to a total of 180 kW, that is 45 kW
foreach thermal element.
1Thermal element = 90 kW = 100%
4Thermal elem.= 90 kW x 4 = 360 kW = 400%
400% : 360kW = 200% : X
X = (200x360) : 400 = 180 kW output shared on 4 thermal elements
Output shared on 4 thermal elements : total output = 180:360 = 0,5 = 50%
Such principle provides clearly efficien-
cies much higher than those obtained in
traditionalgroupsofsmallboilers installed
in cascade.
Whenthe output shared on each thermal
element is less than 22 kW, one thermal
element after the other is automatically
excluded and the remaining output is
shared on thermal elements having the
smallest number of operation hours (by
the automatic operation-time calculating
system).
Modulation,i.e. outputreduction, isbased
onthe differencebetween theset temper-
ature (or the temperature calculated by
the outer compensator) and the global
flowtemperature.
When no ignition occurs, the ignition de-
vice puts to lock out position the thermal
elementconcerned.
Efficiency of a thermal element working at full capacity
(90 kW) = 103 % (in condensation)
Efficiency of a thermal element working at reduced capacity
(45 kW) = 107 % (in condesation)
Efficiency of a thermal element working at minimum capacity
(22 kW) = 109 % (in condesation)
All the thermal elements work in parallel at the same output, equalizing,
thus, the C.H. system efficiency to the one of the thermal element.
0
5
10
15
20
25
30
35
40
kW
mod 1
45
50
55
60
65
70
75
80
85
90
4 thermal elements of 90 kW each working
at 50% of the output give = 180 kW = (200%),
i.e. 45 kW / thermal element
% (p.c.i.)
P
(kW)
20
105
109
40 8060
107
100 % = 90 kW
50 % = 45 kW
90
45
22
1 thermal
element
1 thermal
element