Ideas and forms in evolution

DUA PLUS is a natural draught or roomsealed forced draught wall hung gasboiler, with electronic ignition, ideal tosatisfy all the customer’s needs, whopretends quality and high performances,joined to the dependability, the traditionalUNICAL’s “mission”, whose this productis the evolution confirmation.DUA PLUS is a boiler which conjugatesthe past with the future, taking, asreference, the bases of the experiencemade with the previous model with theaddition of all the most advancedtechnology, to supply the user with themaximum well-being. No other competingboiler can, in fact, summarize in an uniquemodel, the contents of DUA PLUS:

• the design solidity

• the flexibility of the D.H.W.priority systems

• the economy of management• the practicality in the installation• the quickness in the maintenance• the simplicity of the controls

• the stylishness of the design

naturaldraughtTYPE room

sealedelectric

divertingvalve

RTN 24

CTN 24 E

RTFS 24

CTFS 24 E

The mechatronics of DUA PLUS

Double safety, with two electronicignition electrodes

ElectricalDiverting valve

Pumpwith three selectable speedsand built-in air vent

Anti-frost protections

Manual adjustment andautomatic action by-pass

Room temperaturemodulating control

High efficiencyby-thermal engine: > 92%

Swinging panel boardfor a quick service

Simple use of the controls Led diagnosticsfor a quick fault finding

TES (Thermostatic Energy Saver)economiser for GAS-WATER andTIME saving

Easy to useDUA PLUS is designed to guarantee themaximum ease to the user. The panelboard has been studied according tothe most recent fundamental ergonomicrules: the selector switch of the primaryfunctions is placed in the center, with, allaround, the secondary controls. A seriesof led indicate the functions ON, showthe temperatures of heating and domestichot water and the type of fault whichcould have occurred within the boiler.

The well-being controls

Multifunction switchHeating only position the boiler works

for C.H. only.Summer position he boiler works for

D.H.W. production onlyWinter position the boiler works for heating

and D.H.W. productionOff/anti-frost position the boiler is Off; only

anti-frost protection is On.

Double scale thermometerthrough this thermometer

it is possible to read:- the C.H. flow temperature

on the L.H. side scale

- the D.H.W. temperatureon the R.H. side scale

Outer sensor calibration buttonAdjust the compensation curve for the control of the roomtemperature depending on the outer temperature (it works onlywhen the outer temperature sensor is fitted).

Special functions buttonStarts the boiler for technical maintenance use.

Heating temperatureadjustement

This knob allows the adjustementof the C.H. flow temperature.

Adjustement range: 35 to 85°C.

D.H.W. temperatureadjustement

This knob allows theadjustement of the D.H.W.temperature. Adjustement

range: 35 to 65°C.Signaling lamp

is ON if the special functions button is in operation.

Reset buttonButton resetting the boiler operationafter a lock-out of the burner control.

Failure lamp:Indicates the lock-out of the burner control.

Fault signaling lampIndicates a fault in the boiler operation.

Burner On LampIndicates the good operation of the burner.

Supply line On LampIndicates the power supply is On.

TES: Thermostatic Energy Saver

Clever Savingwith DUA PLUSThanks to this patented device “TES”, theuser, at each drawing of D.H.W., consumesand pays what he indeed uses.

In the 1st phase the TES allows the flowrate of approximately two liters per minof water with a temperature lower than30°C. In the mean time the burner, at itsmaximum output, warms very quicklythe water which, as it is possible to see,in the 2nd phase causes the heating of thethermal sensitive element (wax) which,at its turn, pushes out the stainless steelshaft (P), causing the complete openingof the water pass.

The consumptions indicated in the besidefigure, without and with TES, areconsiderably different.The saving depends on the number ofwater drawings. If we consider, as anexample, a family of three persons, whichnormally makes 15 water drawings a day,the annual saving can reach 350 m3 ofgas and 70 m3 of water.With DUA PLUS, then, the reduction ofthe costs and the reduction of gas andwater waste is a reality.In the comparison between the DUAPLUS and an other boiler, it is clear thatthe DUA PLUS saves, at each drawing ofwater, 69 liters of gas, 16 liters of waterand 90 seconds to produce warm waterat a temperature of 40°C.

The comparison between a DUA PLUS and a boiler without TES highlights that to produce warm water at 40°C, DUAPLUS consumes only 39 liters of gas and 7 liters of water, waiting just 1 min.

The TES is made of a special thermal sensitive element, placed downstream the heat exchanger, which allows theD.H.W. passage at the maximum flow rate only when the water is really hot.

TO PRODUCE WATER AT 40°C

GAS WATER TIME

150 sec.

23litres

7litres

39litres

60 sec.

STRUCTURE OF THE TES DEVICE

2nd PHASEtemp. 31°Ctemp. < 30°C

1st PHASE

POSITION OF THE TES

Coldwater

Warmwater

TES

P

C

E

E - Thermal sensitive elementP - Stainless steel shaftC - Water pass

108litres

RFGM C

The electric diverting valve

VE

The best solutionWhy to choice a DUA PLUS with electricdiverting valve?Because only with this solutionit is possible to combine the new systemsof electronic controls, as the modulatingchrono-thermostat “TM 2000”with the control of the room temperaturedepending on the outer temperature.The motorised valve, electrically controlledby these devices, answers immediatelyto each signal, thus guaranteeing

high precision in the temperature controland reducing the fuel consumptions.An alternative that UNICAL, notoriouslyin advance with its proposals,could not disregard for the well-beingof the users.

HYDRAULIC CIRCUIT OF DUA PLUSCTFS 24 E

C - Domestic Hot Water outletG - Gas inletF - Domestic Cold Water inletVE - Electric valveM - C.H. flowR - C.H. return

On-off or modulating type.Which one to choice?The On-Off thermostat intervenes byswitching On and Off the boiler whenthe room temperature is reached (fig. 1).The heating output and temperature aremanaged by the boiler. The actual roomtemperature is influenced by severalvariables, as the thermal inertia of theC.H. system and the answer delay of thethermostat: it follows a lower precisionin the temperature control.The modulating chrono-thermostat“TM 2000” controls directly the burneroutput adapting it immediatelyto the pre-set temperature (fig. 2).It results:

• a smaller number of switching On andOff, with a lower use of the devices(fan, gas valve, pump, etc.);

• a smaller heat loss through the chimney;

• a higher speed in reaching the steadystate condition;

• a higher precision in the adjustment,because the radiators heating watertemperature is continuously controlledby the room thermostat;

• reduction of the excessive radiatorsoverheatings, which are the cause ofdry air, reach in suspendible dusts,particularly annoying.

The“TM 2000”brainy comfort• The self-adaptation: with an outer

temperature lower than 8°C,speeds up the adaptationto the pre-set temperature.

• The pre-heating optimization:establishes the best advanced ignitionto obtain the requested temperature atthe requested time.

• The outer sensor: the coupling of theOn-Off chrono-thermostat with theouter temperature sensor controls theboiler output depending on the outertemperature, thus assuring the pre-setroom temperature.

High efficiencyouter compensatorTo get very high seasonal efficienciesand a pleasant room comfort, the preciseroom temperature control is fundamental.DUA PLUS is suitable to be connected withseveral types of chrono-thermostats, bothOn-Off and modulating type with externalsensor.

DUA PLUS for the maximum comfort

TAonoff

TA

fig. 1

fig. 2

ON-OFF THERMOSTAT

MODULATING CHRONO-THERMOSTATTA = Temperatura ambiente prescelta

TA = pre-set room temperature

AVAILABLE AS ACCESSORY Code No. 00261950

Front accessto all componentsDUA PLUS has been designed takingparticular care to the easy use,to the quickness in the installationand to easy access to the componentsto facilitate the ordinary andextraordinary service, thus reducingthe service costs.Large are, in fact, the spaces betweenthe components and few are the toolsrequired for service operations,all executable from the frontof the appliance:• two adjustable wrenches,• a cross screw driver,• a socket wrench,• a multimeter,• a gas pressure gauge.

Easy installationand service

Boiler connections at 15 cm fromthe rear wall to facilitate the installation

Opening of the sealed roomwith quick fasteners

Opening of the combustionchamber with release levers

Burner removal by front sliding withoutremoving the gas train

Heat exchanger removalby front ward sliding

Fan frontward removalwith removal of just one screw

Removal of the casing front and sidepanel by vertical sliding

KIT BKIT A

GC

FM

R

Accessoriesandmountingjig

30 3065 65 65 65

60

50

M C G F R

A standard pipes kit, the screwanchors and a mounting jig allow thequick mounting of the DUA PLUS,whilst other optional accessoriescomplete the range. The professionalinstaller can easily connect it to adigital or analogue room thermostatto optimize its operation.

Every boiler is equipped with a metalmounting jig, with the indicationsconcerning the wall fitting, theconnection reference for the gas, coldwater inlet, hot water outlet, C.H.flow and return.

ELECTRONIC ANALOGUE DAILYCHRONO-THERMOSTAT

DIGITAL WEEKLY CHRONO-THERMOSTAT SD 700OUTER TEMPERATURE SENSOR

METAL MOUNTING JIG

AIR/SMOKE COAXIAL DUCTS

Cod. 00360457

Cod. 00260737Cod. 00260738Cod. SND 0140C

Cod. 00360535

AIR/SMOKE SEPARATE DUCTS

Cod. 00360460

Cod. KIT5500C

DUA C/DUA PLUS C ADAPTATION KIT

Cod. 00360682

ISOLATING BALL VALVES KIT

M - Mandata impiantoC - Acqua caldaG - GasF - Acqua freddaR - Ritorno impianto

attacchi

3/4"1/2"3/4"1/2"3/4"

1814141418

Øtubo rame

Technical data

0

1

2

3

4

5

6

100 300 500 700 900 1100 1300

V3V2

V1

450 360

Safeprotection

The professional installer asks forperformances of the products heinstalls, but also he asks for quickinstallations, free from obstacles, withthe minimum impact for his clients.

The casing is supplied, separate fromthe boiler, but in the same strongpacking, to be fitted later on, whenthe installation is finished.

DIAGRAM FLOW RATE/MANOMETRIC HEAD

(*) Calculated for a maximum temperature of 90°C

(**) Medium flow rate for a t = 25 K

kW

kW

%

%

%

%

°C

g/s

%

%

l/min

bar

l

l

l

bar

l/min

l/min

V-Hz

A(F)

W

IP

kg

Model DUA PLUS CTN DUA PLUS CTFS

24.35-10.84

26.5

91.21

90.33

93.1

1.0-1.89

107.6

15.93-15.58

2.9-6.8

12.3-6.9

II2H3+

7.8

0.5-3

7

130

3.5

0.5-6

10

13.7

230/50

4

137

X4D

45

24.01-11.07

26.5

90.01

88.62

93.1

3.06-3.09

87

17.7-19.5

2.6-5.3

9.6-6.9

II2H3+

7.8

0.5-3

7

130

3.5

0.5-6

10

13.7

230/50

4

90

X4D

42

NOMINAL AND MINIMUM OUTPUT

NOMINAL INPUT

WATER EFFICIENCY AT 100% LOAD

WATER EFFICIENCY AT 30% LOAD

COMBUSTION EFFICIENCY AT 100% LOAD

HEAT LOSSES THROUGH THE CASING MIN/MAX

MAX SMOKE TEMPERATURE

SMOKE FLOW RATE MIN/MAX

CO2

CHIMNEY HEAT LOSSES WITH BURNER IN OPERATION MIN/MAX

APPLIANCE CATEGORY

MIN WATER THROUGHPUT IN THE C.H. CIRCUIT WITH T = 20K

C.H. CIRCUIT MIN/MAX WORKING PRESSURE

CLOSED EXPANSION VESSEL TOTAL CAPACITY

C.H. CIRCUIT MAX WATER CONTENT *

PRIMARY CIRCUIT WATER CONTENT

D.H.W. MIN/MAX WORKING PRESSURE

D.H.W. FLOW ADJUSTER

CONTINUOUS D.H.W. PRODUCTION – MIXED **

ELECTRICAL SUPPLY TENSION/FREQUENCY

MAIN FUSE

MAXIMUM OUTPUT ABSORBED

DEGREE OF PROTECTION

NET WEIGHT

Unical AG declines any liability for the inaccuracies that may appear due to errors in transcription or printing. It also reserves the right to introducethose modifications to its products that it considers necessary or useful, without compromising the essential characteristics of the said products.

AG S.p.A. 46033 casteldario - mantova - italy -tel. 0376/57001 (r.a.) - telefax 0376. 660556 - e-mail: info@unical-ag.com

Unical AG declines any liability for the inaccuracies that may appear due to errors in transcription or printing. It also reserves the right to introducethose modifications to its products that it considers necessary or useful, without compromising the essential characteristics of the said products.

AG S.p.A. 46033 casteldario - mantova - italy -tel. 0376/57001 (r.a.) - telefax 0376. 660556 - e-mail: info@unical-ag.com