Unical DUA plus 30 mtank User manual

00333636 - 1st édition - 09/2010
GB
INSTALLATION AND USER
INSTRUCTION MANUAL
DUA
plus 30 tank

General information
2
While thanking you for buying an UNICAL product we invite you to carefully read the following forewarnings:
IMPORTANT
This INSTRUCTION MANUAL, which is an integral and indispensable part of the product, must be handed over to the user by
the plumber.
Read carefully the forewarnings contained in this manual because they supply important indications concerning the
safetywhen using and maintaining the boiler. Kept the manual in a safe place for any future reference.
The boiler must be installed by qualified personnel, in compliance with all applicable laws and standards, 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.
After removal of the packaging, which has to be sent to specific waste management sites for recycling, check that the boiler is intact and
that it has not been damaged during transport and handling. Keep the packaging out of the reach of children as it may represent a choking
and suffocation hazard. Do not install equipment which is patently damaged and/or faulty.
Before installing the boiler, check that the technical data supplied by Unical, correspond to requirements for its correct use in the system.
Before making any service on to the boiler switch off the power supply.
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 boiler and expose people, animals and property to danger.
To grant the efficiency of the appliance and for its proper operation it is necessary to do a periodical service according to the
UNICAL's indications and local laws in force.
The manual must be handed over with the boiler should it be sold or transferred, in order that the new owner and/or installer can consult it.
Only original accessories must be used for all boilers supplied with optional kits (including electrical ones).
This boiler must be used for the purposes for which it has been designed. Any other use shall be considered incorrect and therefore
dangerous.
Damage and/or injury caused by incorrect installation or use and/or damage and/or injury due to non-observance of the manufacturer’s
instructions shall relieve UNICAL from any and all contractual and extracontractual liability.
To guarantee efficiency and correct functioning of the equipment it is legally binding to service the boiler 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.: 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;
- open doors 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, which shows, in addition to the technical
features, also the gas type for which it is prepared to work. In case these indications do not correspond to your requirements, please
contact your nearest Unical supplier. Thanks for that.
"WATER TREATMENT IN C.H. SYSTEM FOR CIVIL USE"
NOTE FOR INSTALLER AND USER
1) The frequency of the cleaning of the D.H.W. heat exchanger is related to the hardness of the feeding water.
2) With a water hardness higher than 14°f the use of antiscaling devices, whose choice will be made on the base of water characteristics,
is suggested.
3) To increase the resistance to the scaling, a D.H.W. temperature adjustment very close to that one of the actual use, is suggested.
4) The adoption of a modulating room thermostat reduces the scaling danger.
5) We advise you to verify the state of cleaness of the D.H.W. heat exchanger at the end of the first year and subsequently every two
years.
PED Declaration
The appliance DUA plus 30 micro tank
is not under the scope of the PED Directive 97/23/CE, because it belongs to a category lower than the 1st, on the base of the comparation
of their features with the limits shown on the table 4 of the directive. Furthermore the appliance is already covered by the Directives 90/396/
CE (GAD - Gas Appliances Directive) and 73/23/CEE (LVD - Low Tension Directive)

General information
3
DATA PLATE DESCRIPTION
LEGEND:
1 = CE Surveillance notify body
2=Boiler type
3=Boiler model
4=Number of stars (Directive 92/42/CEE)
5=(S.N°) Serial number
6=P.I.N. code
7=Approved fluing configurations
8=(N0x) N0x class
A Central Heating circuit features
9=(Pn) Nominal output
10 = (Pcond) Condensing nominal output
11 = (Qmax) Nominal heat input
12 = (Adjusted Qn) Adjusted for nominal Heat input
13 = (PMS) Max. pressure C.H. system
14 = (T max) Max. C.H. temperature
B Domestic Hot Water circuit features
15 = (Qnw) Nominal heat input in D.H.W. mode (if different from Qn)
16 = (D) Specific D.H.W. flow rate according to EN 625-EN 13203-1
17 = (R factor) N° taps based on the quantity of water declared EN
13203-1
18 = (F factor) N°stars based on the quality of water declared
EN 13203-1
19 = (PMW) Max. pressure D.H.W. system
20 = (T max) Max. temperature D.H.W system
C Electrical features
21 = Electrical power supply
22 = Consumption
23 = Protection grade
D Countries of destination
24 = Direct and indirect country of destination
25 = Gas family
26 = Supply pressure
E Factory setting
27 = Adjusted for gas type X
28 = Space for national brands
CE Marking
- The CE marking documents that the boilers satisfy:
- The essential requirements of the Directive regarding gas
appliances (Directive 90/396/CEE)
- The essential requirements of the Directive regarding
electromagnetic compatibility (Directive 89/336/CEE)
- The essential requirements of the Efficiency Directive (Directive
92/42/CEE)
- The essential requirements of the low voltage Directive (Directive
73/23/CEE)
®
1
2
3
5
7 8
6
4
9
11
13
10
12
14
15
17
19
16
18
20
28
A
B
21 22
23
24 25 26
27
C D
E

General information
4
1TECHNICAL CHARACTERISTICS AND
DIMENSIONS...................................................................... page 5
1.1 Technical characteristics ..................................................... page 5
1.2 Dimensions ............................................................................ page 5
1.3 Hydraulic circuits .................................................................. page 6
1.4 Operational data.................................................................... page 7
1.5 General specifications .......................................................... page 7
INSTRUCTIONS FOR
THE INSTALLER ............................................................. page 8
2.1 Installations conditions ......................................................... page 8
2.2 Installation .............................................................................. page 8
2.2.1 Packaging ................................................................. page 8
2.2.2 Position of the boiler ................................................. page 9
2.2.3 Assembly the boiler.................................................. page 9
2.2.4 Ventilation .................................................................. page 10
2.2.5 Smoke evacuation systems .................................... page 11
2.2.6 Smoke discharge system forced draught boilers.. page 12
2.2.7 Smoke discharge with separate ducs Ø80 mm..... page 14
2.2.8 On site combustion efficiency measurement ......... page 15
2.2.9 Gas supply line ........................................................ page 16
2.2.10 Hydraulic connections ............................................. page 16
2.2.11 Electrical connections .............................................. page 16
2.3 Electrical wirings ................................................................... page 17
2.3.1 Actual connection diagram ...................................... page 17
2.3.2 Jumper position ........................................................ page 19
2.4 Filling of the heating system ................................................. page 20
2.5 Starting the boiler .................................................................. page 20
2.6 Burner adjustment................................................................. page 21
2.7 Adaptation to the use of other gas....................................... page 22
2.8 Fault finding and reparation .................................................. page 23
INSTRUCTIONS FOR THE USER ..................... page 24
3.1 Panel board ........................................................................... page 24
3.2 Ignition and extinction ........................................................... page 26
3.3 Notes...................................................................................... page 26
2
3
GAS VALVE LABEL
00331980
For your own safety, observe these safety instructions.:
PLEASE NOTE:
User tip for the optimum utilisation
and setting of the control(s) plus
useful information.
WARNING
from risk of electric shock.
WARNING
Identifies potentially dangerous
situations.

5
Technical features and dimensions
fig. 1
1.2 - DIMENSIONS
MC.H. system flow
CD.H.W.outlet
GGas inlet
FD.C.W. inlet
RC.H. system return
view from above
view from below
450
863
373
190
105 120 120 105
218
143
163,5
154
M
C
GFR
1TECHNICAL FEATURES ET DIMENSIONS
- Heating output adjustment independent
from the D.H.W. output
- Flame modulation according to the
absorbed output.
- Pump in operation also during the D.H.W.
drawings.
- Boiler with protection degree IP X4D
- Luminous indications of: D.H.W. demand -
Heating demand - Power ON - Fault
indication - Burner On - Thermometer.
- D.H.W. priority flow switch.
- Pressure switch against lack of water.
- Boiler manometer.
- Boiler filling cock.
- D.H.W. flow limiter at 12 l/min.
- Automatic air vent onto the circulating
pump
- Boiler temperature adjuster (35 to 85 °C)
- D.H.W. temperature adjuster(40 to 55 °C)
- Motorised diverting valve
- Safety thermostat
- Anti-frost protection
- Winter/Summer/Antifrost selector
- Mounting jig for preparation of hydraulic
connections.
- Electronic ignition.
- Casing with oven dried powder painting
1.1 - TECHNICAL
FEATURES
The DUA plus 30 µtank boiler is a gas fired
unit operating with a built-in atmospheric
burner with electronic ignition; it is supplied
only in room sealed forced draught version
and with electrically operated diverting valve.
It is foreseen for heating and domestic hot
water production purposes.
The nominal output of DUA plus 30 µtank is
29,4 kW, both in heating and D.H.W.
production mode.
The DUA plus 30 µtank is complete with all
the safety and control devices foreseen by
the Standards and, for its caracteristics,
is considered a low temperature boiler.
The electronic P.C.B. of the boiler adjustes,
through a continuous modulation of the gas
valve, the burner capacity according to the
actual heat demande.
COMPONENTS DESCRIPTION
- Dual (bithermic) copper heat exchanger.
- Micro-tank with 4 liters capacity of boiler
water.
This control P.C.B. guarantees the priority of
the domestic hot water production on to the
heating fonction and shows the heating flow
and domestic hot water temperatures.
The air suction and the smokes evacuation
are done through a coaxial duct, whose
length can vary.
This type of boiler shall be destined only to
the use for which it has been conceived.
IMPORTANT
The DUA plus 30 µ tank boiler is foreseen
for heating the water to a temperature lower
than the boiling temperature at the
atmospheric pressure. It must be connected
to a C.H. closed expansion system and to a
D.H.W. distribution system compatible with
its output and its technical performances.

6
Technical features and dimensions
1.3 - HYDRAULIC CIRCUIT
RF
G
MC
fig. 2
DUA plus 30 µ tank
1
2
3
4
6
5
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
25
24
26
27
28
23
29
1 Three way motorised diverting valve
2 Pressure switch against lack of water
3 Boiler safety valve
4 Diverting valve actuator
5 IBurner injectors
6 Ionisation probe
7 Ignition electrode
8Main heat exchanger
9 Room sealed combustion chamber
10 Micro-accumulation tank(4L)
11 Micro-accumulation temperature sensor
12 Extraction fan
13 Microswitch of the smoke pressurestat
14 Safety pressureswitch of smoke circuit
15 Air intake and smoke evacuation duct
16 Boiler expansion tank valve inflation
17 Boiler expansion tank 10 Lt.
18 Safety thermostat
19 Ignition electrode
20 Flow temperature sensor
21 Air vent
22 Pump with built-in automatic air vent
23 By-pass
24 Modulating gas valve
25 Boiler draining valve
26 Domestic Hot Water flow restrictor
27 Filtre
28 Volumetric counter
29 D.H.W. temperature sensor
M Heating flow
C D.H.W. outlet
G Gas supply
F D.C.W. inlet
R Heating return

7
Technical features and dimensions
1.4 - OPERATIONAL DATA
For some data (NOZZLES - BURNER GAS PRESSURE - DIAPHRAGMS - INPUTS - GAS CONSUMPTIONS)
refer to paragraph ADAPTATION TO THE USE OF OTHER GAS on page 23.
See Data plate
9.55
0.5
3
8
85
35
10
185.7
0.5
6
13.5
12
9.1
10.1
11.6
13.5
16.3
35 - 55
230/50
4
143
X4D
51
Boiler category
Minimum water low rate in heating circuit (DT 20°C)
Minimum pressure in heating circuit
Maximum pressure in heating circuit
Water content of the primary circuit
Maximum operation temperature in heating mode
Minimum operation temperature in heating mode (*)
Expansion vessel total content
Maximum water content of the heating circuit (max. temp. 90°C)
Minimum pressure in the D.H.W. circuit
Maximum pressure in the D.H.W. circuit
Specific D.H.W. flow rate ( t 30°C according to EN 625)
Flow rate of the D.H.W. flow restrictor
Contiunuous D.H.W. production with t 45 K
Contiunuous D.H.W. production with t 40 K
Contiunuous D.H.W. production with t 35 K
Contiunuous D.H.W. production with t 30 K
Contiunuous D.H.W. production with t 25 K
D.H.W. temperature adjustable between
Electrical power supply Tension/Frequency
Supply fuse
Maximum absorbed output
Insulation degree
Net weight (dry)
l/min
bar
bar
l
°C
°C
l
l
bar
bar
l/min.
l/min.
l/min.
l/min.
l/min.
l/min.
l/min.
°C
V-Hz
A (F)
W
IP
kg
Nominal output
Minimum output
Actual water efficiency at 100 % of nominal load
Minimum water efficiency required at 100 % of nominal load
Actual water efficiency at 30 % of nominal load
Minimum water efficiency required at 30 % of nominal load
Star number (according to Efficiency Directive 92/42/CE)
Combustion efficiency at 100 % of nominal load
Combustion efficiency at minimum load
Heat losses through the casing (min. / max.)
Maximum net smoke température (Ts- Ta)
Massive smoke flow rate (min. / max.)
Air exces (lambda)
CO2
NOx (ponderal value according to EN 297/A3+EN 483)
NOx class (ponderal value according to EN 297/A3 + EN 483)
Chimney heat losses with burner in operation (min./max.)
Chimney heat losses with burner shut-off
kW
kW
%
%
%
%
n.
%
%
%
°C
g/s
%
%
mg/kWh
%
%
DUA plus 30
µ tank
29.95
13.9
93.03
92.95
92.52
90.43
94,78
91,53
1.87 - 1.75
78,7 - 93.7
14.27 - 16.33
41.72
3,8- 8.0
144
3
11.27 - 6.8
0.398
DUA plus 30 (*)
µ tank
1.5 - GENERAL SPECIFICATIONS
(*) Warning: The utilisation of this type of boilers in the "floor heating systems" needs the use of specific equipments (e.g.:
UNICAL Thermic Module) to avoid all risks of smoke condensation within the boiler.

8
Installation info
fig. 3
2INSTRUCTIONS FOR
THE INSTALLER
2.1 - INSTALLATION
CONDITIONS
DUA plus 30 µtank is a gas boiler which
must be installed in accordance with the
latest regulations or rules in force.
For the boiler category, which changes
according to the destination country,
see page 3.
NOTE:
Observe the corresponding technical rules
and the building supervisory and statutory
regulations of the country of final use
when installing and operating the system.
Always ensure that an appropriately
specialised company is entrusted with
installation, gas supply and flue gas
connection, commissioning and power
supply, as well as all servicing and repair
works.
Work on gas conduits and fittings must only
be carried out by a registered service
provider.
The system must be cleaned and serviced
once a year. This includes an inspection of
the entire system to see if it is in full
working order.
Defects and faults must be eliminated
immediately.
Please note that we can accept no liability
whatsoever for loss or injury resulting from
unauthorised adjustment or manipulation of
the system’s control or regulating devices.
2.2 - INSTALLATION
2.2.1 - PACKAGING
The Dua plus 30 µ tank boiler is delivered
packaged in a strong cardboard box. After
removal of the boiler fron the box make sure
that it is not damaged. The packaging
materials are recyclable: then, send them to
the appropriate selection zones.
The packaging may represent grave
dangers for the children; do not leave them
to their reach.
Unical declines all responsibilities for
damages to persons, animals and things,
deriving from the non observance of this
clause
The casing's panels are packaged separat-
ly, but in the same box of the boiler, to better
protect them from posiible damages.
Under the panel board there is a plastic bag
containing:
- This instruction manual.
- Boiler mounting jig
- The paper template for the positioning of
the boiler on the wall.
- The instructions and the screws for the
mounting of the casing panels.
- N. 3 extractable cable glands for electrical
connections for room thermostat, outer
temperature sensor and an eventual
supplementary pump.
460
500
900
- Instruction for the mounting of the smoke
evacuation diaphragm on the fan outlet.
- Smoke évacuation diaphragm.

9
Installation info
2.2.2 - POSITIONING OFTHE BOILER
Every boiler is supplied with a dedicated
"Metallic mounting jig" to allow the correct
positioning of the gas, water and C.H.
system connections when the hydraulic
system is being laid out and before the boiler
is installed.
This mounting jig must be fixed to the wall
chosen for the installation of the boiler using
two screws with expanding dowels.
The lower part of the mounting jig allows the
correct marking on the wall of the points
where the fittings for the gas, C.H. flow and
return, D.H.W. and D.C.W. have to arrive.
Determine the position of the boiler taking
care:
- of leaving a minimum clearance of 50
mm on both sides of the boiler to allow
accessibility for service.
- of a good resistance of the screws
supporting the boiler on the wall.
- of avoiding to position the boiler above
an equipment whose use could be
prejudicial for the boiler (stove with
emission of greasy vapours, washing
machines, etc...).
The mounting jig allows the completion of all
the connections and the making of the
soundness test of the full installation without
the boiler in place.
If the boiler is not put in place immediately,
protect the different connections in order to
avoid that the mortar and the paint
cannot compromise the soundness of the
subsequent connections.
Because the temperature of the wall, on
which the boiler is fitted, does not rise more
than 60 K when the boiler is in operation,
there are no special requirements to comply
with.
NOTE: Only if an air intake and smoke
evacuation system with two separate
ducts is used, the smoke evacuation duct
has to be insulated with 20 mm thick
insulation material when crossing
flammable walls.
2.2.3 - ASSEMBLING THE BOILER
Before connecting the boiler to the D.H.W.
and heating system pipes, carefully clean
the pipes to remove all traces of metal
resulting from processing and welding
operations as well as any oil and grease
which could damage the boiler or
jeopardize its operation.
MOUNTINGTEMPLATE
fig. 4
M= C.H. flow 3/4"
C= D.H.W. outlet 1/2"
G= Gas inlet 3/4"
F= D.C.W. inlet 1/2"
R= C.H. return 3/4"
732,5 172,5
300
120 120
192,5
58
157
Unical refuses all liability for injury to persons
and animals or damage to property resulting
from non-observance of the above.To install
the boiler:
- Fix with tape the paper template to the
wall
- make two Ø 12 holes in the wall and
insert the hooks;
- position the junction points for the
connection of the gas supply pipe, cold
water supply pipe, D.H.W. outlet, CH flow
and return in the positions shown by the
template.
- fit the boiler onto the support hooks;
- connect the boiler to the gas pipe,
domestic cold and hot water pipes, CH
flow and return pipes.
- connect to electrical supply.
NOTE:NOTE:
NOTE:NOTE:
NOTE:
--
--
-Do not use solvents which couldDo not use solvents which could
Do not use solvents which couldDo not use solvents which could
Do not use solvents which could
damage the components.damage the components.
damage the components.damage the components.
damage the components.

10
Installation info
2.2.4 -VENTILATION
The DUA plus 30 Microtank is a forced
draught, room seled boiler; so it does not
need particular ventilation openings for the
combustion air, in the room in whichit is
installed.
POSITIONING OF TERMINALS FOR TYPE ‘’C’’ BOILERS
Position of the terminalPosition of the terminal
Position of the terminalPosition of the terminal
Position of the terminal Min. DistancesMin. Distances
Min. DistancesMin. Distances
Min. Distances
mm
-Under a window A 600
-Under a ventilation opening B 600
-Under a gutter C 300
-Under a balcony (1) D 300
-From an adjacent window E 400
-From an adjacent ventilation opening F 600
-From vertical or horizontal air pipes or drains (2) G 600
-From an external corner of the building H 300
-From an internal corner of the building I 1000
-From the ground or from another floor L 1800
-Between two vertical terminals M 1500
-Between two horizontal terminals N 1000
NOTES
(1) Terminals below a practicable balcony shall be arranged in such a way as to assure that the total run of smokes, from their outlet
from terminal up to outlet from balcony external perimeter, including the height of protection baluster, if any, is not less than 2 m.
(2) Distances of not less than 500 mm shall be adopted in placing the terminals, due to the proximity to materials subject to the action
of products of combustion such as plastic gutters or waterspouts, wooden jetties, etc.) unless adequate screening measures are
taken for the said materials.
The forced draught, room seled boilers, nor-
mally should evacuate the smokes on
the roof of the building.
When, in some country, it is allowed to eva-
cuate on the front of the building, the
following distances of the terminals, have
to be complied with:
TERMINALS POSITION
fig. 4

11
Installation info
2.2.5 - SMOKE DISCARGE AND AIR
SUCTION DUCTS CONFIGURATION
TYPES C12, C32, C42, C52, C82
The DUA plus 30 Microtank boiler has been
approved for the following air suction and
smoke evacuation tipes:
C12C12
C12C12
C12 Boiler designed for connection to
horizontal
exhaust and suction terminals directly into
the atmosphere using coaxial or dual ducts.
The distance between the air intake duct
and the flue gas outlet duct must be at least
250 mm and both end sections must
be located within a 500 mm square.
C32 Boiler designed for connection to
vertical discharge and suction outlets
directly into the atmosphere using coaxial
or dual ducts. The distance between the air
intake duct and the flue gas outlet duct
must be at least 250 mm and both end
sections must be located within a 500 mm
square.
C42 Boiler designed for connection to
collective
chimneys including two ducts,
one for the suction of combustion
air and the other for the exhaust
of the combustion products,
through coaxial or dual ducts.
The chimney must comply with
relevant applicable law provisions.
C52 Boiler with separate combustion air
suction and combustion product
exhaust ducts.
These ducts can discharge into areas
with different pressure.
The dual ducts must not be located
on two opposite walls.
C82 Boiler designed for connection to an
air supply terminal and fitted to an individual
or shared chimney.
The chimney must comply with
relevant applicable law provisions.
type
C12
type
C32
type
C52
type C82
type
C42

12
Installation info
Type C12
The maximum autorised length for the
horizontal coaxial pipes is 3 meters; for each
supplementary bend the maximum length will
be reduced by 1 meter; furthermore the pipe
shal have a downward inclination of 1% on
the outlet direction in order to avoid the rain
enter the pipe.
For installations with horizontal coaxial pipe
with length between 0.5 and 1 m, it is
necessary to place, inside the fan outlet, the
diaphragm supplied with the boiler (see fig
5).
Type C32
The maximum allowed length of the coaxial
vertical pipes is 5 meters, included the roof
terminal; for each supplementary bend the
maximum allowed length will be reduced by
1 meter.
For installations with coaxial ducts having a
length between 1.2 and 2.5 m, it is necessary
to place, inside the fan outlet, the diaphragm
supplied with the boiler (see fig. 5).
2.2.6 - SMOKE DISCHARGE SYSTEM
FORCED DRAUGHT BOILERS
DIMENSIONS FOR CONNECTION
OF THE COAXIAL DUCTS
C12: between 0.5 and 1 m with
diaphragm Ø 40 L max = 3 m
fig. 5
Neoprene
Diaphragm
C12: between 1.2 and 2.5 m with diaphragm Ø 40 L max = 3
Diaphragm
gasket
®
plus DUA
fig. 6
190
100
80
863
373
450

13
Installation info
fig. 8
2.2.7 - SMOKES DISCHARGE WITH
SEPARATE DUCTS Ø 80mm
(Type B accessories )
NB: The maximum allowed pressure
drop, according to the type of
evacuation system, cannot be
higher than the value stated on the
installation examples shown on
page 14.
For installations with two separate
ducts, whose pressure drop is
lower than 30 pa, it is necessary to
place the diaphragm, supplied
with the boiler, inside the fan
smoke outlet (see figs. 7 & 8).
Up to a P = 30 Pa
Diaphragm Ø 44
Neoprene
gasket
Diaphragm
fig. 7

14
Installation info
®
plu s DUA
DIMENSIONS FOR CONNECTION OF SEPARATE DUCTS
FOR AIR INTAKE AND SMOKE EVACUATION
fig. 9
863
450 373
120 120 190
Ø 80
fig. 16
Example N.1
_
>500
Hmin. = 150 mm
Example N.1
Primary air intake from an outer wall and
smoke evacuation through a roof terminal.
Maximum allowed
pressure drop: 50 Pa
POSSIBLE CONFIGURATIONS OF AIR
INTAKE AND SMOKE EVACUATION
DUCTS Ø 80

15
Installation info
Example N.2
Primary air intake from an outer wall and
smoke evacuation through the same wall.
Maximum allowed pressure drop: 50 Pa
fig. 11
CALCULATION OF PRESSURE LOSS
FOR DISCHARGE & SUCTION DUCTS
Bear in mind the followingBear in mind the following
Bear in mind the followingBear in mind the following
Bear in mind the following
parameters when calculatingparameters when calculating
parameters when calculatingparameters when calculating
parameters when calculating
pressure losses:pressure losses:
pressure losses:pressure losses:
pressure losses:
- for each metre of duct with Ø 80 (both
suction and discharge) the pressure loss
is 2 Pa;
- for each 90° Ø 80 (R=D) bend with long
radius, the pressure loss is 4 Pa;
- for the Ø 80 L = 0.5 m horizontal air inlet
terminal, the pressure loss is 3 Pa;
Ø 80 L = 0.6 m horizontal discharge end
section, the pressure loss is 5 Pa;
- for the adaptor from coaxial to two separate
ducts, the pressure loss is 4 Pa.
NB: These values refer to discharges
through original UNICAL non-
flexible and smooth ducts.
In both of the following examples
the hypotized compositions of the
intake and evacuation ducts are
possible because the total pressure
loss is lower than 50 Pa, which is
the maximum allowed pressure loss.
Example of check using wide radius
bends:
- 15 m duct Ø 80 x 2 = 30 Pa
-2 x 90° Ø 80 long radius bends 2x4= 8 Pa
- horizontal Ø 80 air inlet terminal = 3 Pa
135
45
250 min.
fig. 12
2.2.8 - ON SITE COMBUSTION
EFFICIENCY MEASUREMENT
(Type A accessories))
Coaxial ducts
To determine combustion efficiency the
following measurements must be made:
- the combustion air temperature measured
in hole 2 (see fig. 12).
- the flue gas temperature and CO2 %
measured in hole 1 (see fig. 12).
Make these measurements with the
boiler running in a steady state
condition.
(Type B accessories))
Separate ducts
To determine combustion efficiency the
following measurements must be made:
- the combustion air temperature measured
in hole 2 (see fig. 12).
- the flue gas temperature and CO2 %
measured in hole 1 (see fig. 12).
Make these measurements with the
boiler running in a steady state
condition.
A
B
Analyser
probes
2
1
Analyser
probes
12
Smokes
Air
- horizontal Ø 80 terminal = 5 Pa
- adaptor from coaxial to
two separate ducts Ø 80 = 4 Pa
Total pressure loss = 50 Pa
Example N.2

16
Installation info
2.2.8 - HYDRAULIC CONNECTIONS
Before installing the boiler we recommend
that the system be cleaned to remove any
impurities which could originate from
components and which could risk damaging
the circulating pump and heat exchanger.
HEATING
The heating flow and return must be
connected to the relevant ¾” connections
of the boiler M and R (see fig. 3).
When determining the size of the heating
circuit pipes it is essential to bear in mind
the pressure losses induced by radiators,
any thermostatic valves, radiator cut-off
valves and the configuration of the system.
In the boiler, between the flow and return
pipes,an automatic bypass device is fitted
(a differential valve with a flow rate of
about 150 l/h) which guarantees always
minimum flow rate through the heat
exchanger, also in the case, for instance,
that all the thermostatic valves fitted on the
radiators, are closed.
It is possible to adjust the by-pass by acting
onto the adjusting screw (see fig. 14).
We recommend that the discharge of the
safety valve mounted in the boiler be
conveyed into the sewer.
If this precaution is not taken, activation of
the safety valve may result in flooding of
the room where the boiler is installed.
UNICAL shall not be held responsible for
damage caused by non-observance of this
technical precaution.
D.H.W. (Domestic Hot Water)
Inlet and Outlet and of D.H.W. must be
connected to the relevant ½” connections
of the boiler C and F (see fig. 7).
For the lower connections positioning,
see the mounting jig of figure 9
The pressure in the water mains must be
between 1 and 3 bar (in case of higher
pressure it is necessary to fit a PRV
(Pressure Reducing Valve).
fig. 8
2.2.9 - GAS SUPPLY LINE
The gas supply line must have a diameter
equal or larger than the one used in the boiler.
Comply with the applicable local installation
requirements which shall be considered as
having been incorporated in full in this
manual.
Before opening the internal gas supply
system; i.e. before connecting the gas
meter, all seals must be checked.
If any part of the system is concealed the
seals must be checked before the pipes
are covered.
The seal test must be conducted using air
or nitrogen at a pressure of at least 100
mbar.
The commissioning of the boiler also
includes the following operations and
checks:
- Opening of the gas gate valve and venting
of the air contained in the piping and boiler,
proceding appliance by appliance.
- Check, with the gate valve of all the
appliance
Off, that there are no gas leaks.
During the 2nd quarter of a hour from the
beginning of the test no pressure reduction
is to be detected on the gas pressure
gauge. If gas leaks have to be found, use
only water soap solution or any other
specific gas leak detector which can be
available on the market. Never look for gas
leaks using a nacked flame.
DIAGRAM FLOW RATE/MANOMETRIC HEAD AVAILABLE FOR C.H. SYSTEM
= By-Pass CLOSED
= By-Pass OPEN
..............
Flow rate l/h (Q)
Available Manometric Head m c.e.
fig. 9
By-Pass CLOSED
By-Pass OPEN
The hardness of the supply water affects
the frequency of the cleaning of the heat
exchanger; the opportunity to install a
water softning device depends on the
characteristics of the water it self.
NOTE:
With a water whose hardness is higher
than 20°f the use of a softner is strongly
recommended
2.2.11 - ELECTICAL CONNECTIONS
The electrical connections of DUA plus 30
µtank are shown in the clause ‘’WIRING
DIAGRAMS’’ (par. 2.3 - pag. 17).
The boiler must be connected to
the mains supply at 230 V - 50 Hz. This
connection is to be perfectly done, as
foreseen by the IEC and local rules and
must be earthed.
This fundamental requirement for safety
purposes must be checked; in case of
doubt, ask for a professionally qualified
technician to check the electrical system.
UNICAL disclaims all liability for damage or
caused by failure to earth the system.
Gas, domestic water and central
heating pipes are not suitable for
earthing purposes.
The boiler is supplied with 1.5 m long
3x0,75mm² cord. PhasePhase
PhasePhase
Phase and NeutralNeutral
NeutralNeutral
Neutral must
compulsory be connected to PhasePhase
PhasePhase
Phase and
NeutralNeutral
NeutralNeutral
Neutral of the supply socket.
A double pole switch with a distance
between the contacts higher than 3 mm,
must be installed upstream the boiler to
enable all maintenance operations to be
carried out safely.

17
Installation info
KEY
A1...A8 = Connectors
ROD = Connector of the ionisation on the
ignition PCB
Y1 = Connector TA - Outer sensor
Y2 = Connector for supply 230 V-50 Hz
CR = Modulanting digital programmer
(option)
CV = Volumetric counter
DK = Pressureswitch against lack of
water
E. RIV. = Ionisation probe fig. 10
2.3 - ELECTRICAL WIRING
2.3.1 - ACTUAL CONNECTION DIAGRAM FOR DUA PLUS 30 mm
mm
mtank
E. ACC.1 = Ignition electrode
E. ACC.2 = Ignition electrode
FL = DHW flow switch
IG = Main switch
MD = Modulating coil
MVD = Three way valve actuator
P = Circulating pump
PV = Fan pressureswitch
SBM = Micro-accumulation temperature
sensor
SE = Outer sensor
SR = Heating temperature sensor
SS = D.H.W. temperature sensor
TA = Room thermostat (option)
TL = Safety thermostat
V = Fan
VG = Gas valve
NA
NC COM
DK
BROWN
WHITE
L1
N
54321
GND1 GND2 GN D4
ROD
N
Y2
GND5
L1 EXT
SENSOR
Y1
PV
BLUE
TL
BLUE
BROWN
BLANC
SBM
RED RED
7654321
CV
BROWN
4321
VG
GREEN GREEN
MD
BROWN
BLUE
E. ACC. 1
TEFLON RED
TEFLON RED
E. ACC. 2
NL
BLUE
BROWN
MVD
E. RIV.
TEFLON
BLANC
SR
76548321
V
BROWN
BLUE
WHITE
WHITE
2 1
21
P
Y
EL/GREEN
BLUE
BROWN
1
2
GREEN
RED (DHW)
BLANC (CH)
SE optional
BROWN
WHITE
CR optional
TA ( ON/OFF)
optional
SIM-CRONO
REGOLAFACILE
BROWN
BLUE
L1
N
NAT
GPL
OFF
ZONE
V
ALVE
(Optional)
(Limit s )
Zone valve
witch
SS
RED
RED
123
RED
BLANC
230 V
50 Hz

18
Installation info
fig. 16
ACCESS TO THE MODULATING PCB
Front view
Panel board side view
AZZURRO
AZZURRO (N)
GIA/VERDE GIA/VERDE
CAVO PVC 3x0, 75 Ø
MA RRO NE
MA RRO NE ( L)
A
B
C
D
Y2
GND 1
E
F
B
C
D
EF
®
plus
DUA
MAX
MAX
80° 60°
65°
70° 55°
60° 50°
50° 45°
40° 40°
30° 35°
20°
-20 °C 10 °C
0 °C
-10 °C
MIN - MAX
GENERAL INFORMATION ON THE
ELECTRICAL CONNECTIONS
Access to the supply terminal block
- WARNING! Disconnect power supply
- Remove the front casing.
- Widen the two plastic flaps (A); pull front-
wards the panel board and rotate it
downwards.
- To get access directly to the connection
zone, unscrew the two screws (B) and
remove the cover (C); if this isn't enough,
unscrew the five screws (D) to get
access completely inside the panel board
(act carefully).
Replacement of the supply cable
When replacing the supply cord, the UNICAL
original one, Part. code 00610308, must be
used.
- Get access to the supply terminal block
Y2 (see previous paragraph).
- Insert the new power supply cord through
the extractable cable gland E
- Pul out the terminal blockY2 and make the
connections respecting the position and the
colours. The female faston of the earthing
wire must be introduced on the tab GND 1.
L1= phase = brown - terminal Y2 - 1
N=neutral = bleu - terminal Y2 - 2
= earth = yellow/green - tab GND1
Room thermostat connection
(ROOM STAT)
- Get access to the terminal block Y1
- Remove the link between terminals 4 - 5.
- Insert the room thermostat cable TA
through the extractable gland, supplied
with the boiler, and connect it to the
terminals 4 and 5.
- WARNING! If an ON/OFF room stat is
used, the jumper JP1 of the modulating
PCB must be positioned between pins 2
and 3 (see fig. 17).
External sensor connectionEXT SENS)
- Get access to the terminal block Y1
- Insert the external sensor cable through
the extractable cable gland, supplied with
the boiler, and connect it to the terminals 2
and 3 of the block Y1; if the cable is of
shielded type, then connect the shield to
the terminal 1 of the block Y1.
For the connection of the ROOM STAT and
the EXT SENSOR, replace the plastic plugs F
of the panel board with the cable glands
supplied with the boiler.

19
Installation info
2.3.2 - POSITIONING OFTHE JUMPERS (their purpose is to implement some functions necessary for the operation
fig. 11
JUMPERS ON THE DISPLAY PCB
JP4 : GAS TYPE SELECTION
Naturl gas: Jumper on NAT (standard supply position)
Liquefied Petroleum Gas: move jumper to LPG position
The standard supply position correspond to the gas type shown on all
the labels within the boiler
JP3 : EXTRNAL TEMPERATURE COMPENSATION FOR OUTER SENSOR
Boiler with outer temperature sensor: jumper on
J
Boiler without outer temperature sensor: jumper on OFF
JP2 : SELECTION OF PUMP OPERATION MODE
If pump has to work continuously: jumper on 1
If pump has to stop after an overrun of 5 min since the stop of the heating
demande: jumper on pos. 2 (standard supply position)
JP1 : CHRONOSTAT FUNCTION (do not change posion of the jumper)
This function is not yet available.
Jumper on (Standard supply position: for a good working keep the jumper in
this position).
T°C0123456789
032755 31137 29607 28161 26795 25502 24278 23121 22025 20987
10 20003 19072 18189 17351 16557 15803 15088 14410 13765 13153
20 12571 12019 11493 10994 10519 10067 9636 9227 8837 8466
30 8112 7775 7454 7147 6855 6577 6311 6057 5815 5584
40 5363 5152 4951 4758 4574 4398 4230 4069 3915 3768
50 3627 3491 3362 3238 3119 3006 2897 2792 2692 2596
60 2504 2415 2330 2249 2171 2096 2023 1954 1888 1824
70 1762 1703 1646 1592 1539 1488 1440 1393 1348 1304
80 1263 1222 1183 1146 1110 1075 1042 1010 979 949
90 920 892 865 839 814 790 766 744 722 701
Relation between the temperature (°C) and the resistance (Ohm) of the heatin temp. sensor SR and the D.H.W. temp. sensor
SR. Example: At 25 °C the nominal resistance is 10067 Ohm - At 90 °C the resistance is 920 Ohm.
TABLE OF THE RESISTANCE VALUES ACCORDING TO THE TEMPERATURE OF THE HEATING SENSOR (SR) AND
D.H.W.TEMPERATURE SENSOR (SS)
NAT
GPL
OFF
JP4
JP3 J
JP2
JP1
1
2
1
2
POSITIONING OFTHE JUMPER

20
2.4 - FILLING THE SYSTEM
After completing all the connections of the
system the heating circuit can be filled.
This filling operation must be performed
with care as follows:
- open the air vents of the radiators and
check that the automatic air vent in the
boiler is works properly;
- gradually open the water tap and check
operation of any automatic air vents
installed in the system;
- close the air vents on the radiators as
soon as water comes out;
- use the pressure gauge on the boiler to
check that the pressure has reached the
value of 0.8/1bar;
- close the water inlet tap and then release
the air again through the radiator air vents;
- after switching on the boiler and after the
system has reached the correct
temperature, stop the pump and repeat the
air relief operations;
- let the system cool down and then adjust
the water pressure to 0.8/1 bar.
This must be performed when the system
is cold. Use the temperature and pressure
gauge on the boiler to read the pressure
value of the circuit.
WARNING
The minimum water pressure switch does
not give electrical impulse to the burner to
ignite when the pressure is lower than 0.4
bar. The pressure of the water in the C.H.
system must not be lower than 0.8/1bar; if
this value is lower use the water filling tap
on the boiler to adjust the pressure.
This must be performed when the system
is cold. Use the temperature and pressure
gauge on the boiler to read the pressure
value of the circuit.
fig. 18
- there are no water leaks.
SWITCHING ON AND OFF
To switch on and off the boiler follow the
indications in the “Users’ Instructions”.
- the supply voltage of the boiler is 230 V-
50 Hz;
- the system is correctly filled with water
(pressure at the gauge 0.8/1 bar);
- any gate valves of the system are open;
- the mains gas corresponds to that with
which the boiler has been adjusted;
otherwise convert the boiler to use the gas
available on site (see: “MODIFICATION
FOR OTHER GASES “): this operation
must be performed by qualified
technicians;
- the gas supply taps are open;
- there are no gas leaks;
- the external mains switch is on;
- the boiler’s safety valve is not locked;
2.5 - STARTING THE
BOILER
PRELIMINARY CHECKS
Before starting the boiler check that:
- the boiler installation has been made in
accordance with all the applicable
regulations concerning water and gas
installation, smoke evacuation and electrical
installation
- the flue gas exhaust duct and its terminal
are installed correctly: when the boiler is
switched on there must be no
leakage of any combustion products
from any seals;
9
1
E
2
5
6
7
4
3
EElectrical actuator
1Diverting valve
2Minumum water pressure switch
3Gas valve
4Cold water filter position
5D.H.W. flow switch
7By-pass
8Draining valve with connection for
flexible hose
9
8
NB:NB:
NB:NB:
NB: AfAf
AfAf
After a given period of inactivityter a given period of inactivity
ter a given period of inactivityter a given period of inactivity
ter a given period of inactivity
and without electrical supply theand without electrical supply the
and without electrical supply theand without electrical supply the
and without electrical supply the
pump could be blocked.pump could be blocked.
pump could be blocked.pump could be blocked.
pump could be blocked.
Before switching on the boiler it isBefore switching on the boiler it is
Before switching on the boiler it isBefore switching on the boiler it is
Before switching on the boiler it is
important to restart the pump asimportant to restart the pump as
important to restart the pump asimportant to restart the pump as
important to restart the pump as
follows:follows:
follows:follows:
follows:
- loosen the protection screw in the
centre of the pump motor,
- insert a screwdriver in the hole and then
manually rotate the pump shaft
clockwise.
Once the pump has been restarted tighten
the protection screw and check that there
are no water leaks.
WARNING
Once the protection screw hasOnce the protection screw has
Once the protection screw hasOnce the protection screw has
Once the protection screw has
been removed a little water maybeen removed a little water may
been removed a little water maybeen removed a little water may
been removed a little water may
leak out. Before replacingleak out. Before replacing
leak out. Before replacingleak out. Before replacing
leak out. Before replacing
the casing of the boiler dry any wetthe casing of the boiler dry any wet
the casing of the boiler dry any wetthe casing of the boiler dry any wet
the casing of the boiler dry any wet
surfaces.surfaces.
surfaces.surfaces.
surfaces.