ARCA PIXEL 25 FC User manual

WALL HUNG BOILERS
INSTRUCTIONS MANUAL
To be used for
INSTALLATION, USE AND MAINTENANCE
CONDENSING BOILERS
PIXEL 25 FC
PIXEL 31 FC
IMPORTANT
The first boiler ignition and the warranty have to be carried out by an authorised
personnel
LIB0900PING – 24 pages - 1aedition - 23/02/2006 -

GENERAL RULES
This instruction book is an integrant and essential part of our product and it is delivered together with our heater.
Read carefully the information about safety, installation and maintenance that are shown in it. The heater installation is to
be carried out by qualified personnel according to the present law and the producer instructions.
After having removed the packaging it is better to control the good state of the product. Don't use the heater if you have
any doubt about this just call your supplier.
IMPORTANT: this heater is aimed to warm water at an inferior temperature than that of the boiling at an atmospheric
pressure; it has to be linked to an heating system and/or a hot water distribution net proper to its capacity and power.
This heater has to be used only according to the usage it was planned for. Every kind of other usage has to be
considered unproper and dangerous. The producer is not to be considered responsible for possible damages caused by
this wrong, unproper and unreasonable usage.
Cut the heater from its supply net off before doing every kind of service operations.
Don't obstruct heater aspiration or dissipation grills.
Put the heater out of work if there is any damage or misfunctioning. The repairing must be carried out by an authorized
service operation centre and it has to use only original spare parts.
In order to grant the highest heater efficiency and for its good functioning it is indispensable to follow the producer
instructions.
If you decide not to use the heater any more make all the dangerous parts became harmless.
Don't wet the heater neither with water nor with other liquid substances.
Don't put other items on the surface of the heater.
Before starting every kind of service operation which forsees the burner dismantling or the opening of inspection holes
you have to cut off the electrical supply and close gas cocks.
If there are chimney service operations turn the heater off. After having finished the operation you should call your
qualified personnel and make the relief duct efficiency control.
Don't clean the heater with inflammable substances.
Don't leave recipients of inflammable substances near the heater.
The electrical safety of the heater is assured only if it is linked to an ground system which is respectful of present laws.
Your qualified personnel must control the efficiency of your net because if there are any problems the producer is not
responsable for damages caused by the lacking of a proper ground system.
Control your electrical system capacity which is to be proper to the power required by your heater.
As far as the heater supply is concerned you cannot use adaptators, multiple plugs and extensions.
The use of electrical items implies the careful observation of fundamental rules such as:
1 do not touch the heater with wet hands;
2 do not tear electrical cables;
3 give not allow children or unused persons to use the heater.
All the following instructions that macaws to be take in mind by the technician on the products of the firm ARCA S.r.l.
The ordinary maintenance and the possible reparation of the products must have nade by a center assistance authorized
from the ARCA S.r.l., exclusively using original pspare parts..
Use only flue gas ducts and electric accessories and furnished by ARCA S.r.l.
Do not replace the supply pipe by your own but only by a qualified person.
You have to assure that safety discharge tubes are linked to a relief valve.
Otherwise, there can be an overfload of the heater site caused by the valves safety action and therefore the producer is
not responsible.
System pipes have not to be used as ground plugs for other systems; not only are they unproper to this use but they can
cause serious problems to the appliances which are linked to them.
Please control:
1 the good functioning of the gas inlet system;
2 the correct gas capacity is the one required by the heater power;
3 that the type of gas used is that the heater was projected for.
4 that the gas supply pressure is within the required values of the heater.
5 that the gas inlet system is proper and has all the required safety caracteristics which are forseen by law.
If you feel gas odour do not turn electrical switches on just open your windows and close gas cocks.
Note: due to the high efficiency of these boilers a plume of water vapour will form art the flue
terminal during the operation.
2

SUMMARY
GENERAL RULES ------------------------------------------------------------------------------------------ 2
1. TECHNICAL DATA ------------------------------------------------------------------------------------- 4
1.1 Dimensions ---------------------------------------------------------------------------------------------------------------------4
1.2 Hydraulic scheme -------------------------------------------------------------------------------------------------------------4
1.3 Available head -----------------------------------------------------------------------------------------------------------------4
1.4 General layout of the main components of models PIXEL 25 FC, PIXEL 31 FC----------------------------------5
1.5 Technical data -----------------------------------------------------------------------------------------------------------------6
1.6 PIXEL FC: Electrical scheme-----------------------------------------------------------------------------------------------7
1.7 PIXEL FC: Electrical scheme-----------------------------------------------------------------------------------------------8
2. INSTALLATION INSTRUCTIONS ------------------------------------------------------------------- 9
2.1 Combustion product discharge: PIXEL 25 FC, PIXEL 31 FC ----------------------------------------------------------9
2.1.1 Different venting options - Flue venting ------------------------------------------------------------------------9
2.1.2 Lenght of discharge ducts: PIXEL 25 FC-------------------------------------------------------------------------10
2.1.2.1 Split flue (Ø 80 mm)-------------------------------------------------------------------------------------10
2.1.2.2 Coaxial flue (Ø 60 x 100 mm) ------------------------------------------------------------------------10
2.1.3 Lenght of discharge ducts: PIXEL 31 FC-------------------------------------------------------------------------11
2.1.3.1 Split flue (Ø 80 mm)-------------------------------------------------------------------------------------11
2.1.3.2 Coaxial flue (Ø 60 x 100 mm) ------------------------------------------------------------------------11
2.2 Boiler placing -------------------------------------------------------------------------------------------------------------------12
2.3 Hydraulic connections--------------------------------------------------------------------------------------------------------13
2.4 Electric connections ----------------------------------------------------------------------------------------------------------13
2.5 Gas connection ----------------------------------------------------------------------------------------------------------------14
2.6 Setting of control panel ------------------------------------------------------------------------------------------------------15
2.7 Adjustement instructions: nominal heat and minimal heat ----------------------------------------------------------16
2.7.1 Nominal heat adjustment -------------------------------------------------------------------------------------------16
2.7.2 Minimal heat adjustment---------------------------------------------------------------------------------------------16
2.8 Slow ignition and nominal heat adjustment -----------------------------------------------------------------------------16
2.8.1 Slow ignition adjustment --------------------------------------------------------------------------------------------16
2.8.2 Nominal heat adjustment -------------------------------------------------------------------------------------------16
2.9 Different gases-----------------------------------------------------------------------------------------------------------------16
2.10 Injectors - pressure table: PIXEL 25 FC ---------------------------------------------------------------------------------17
2.10.1 Gas pressure - Heat diagram-------------------------------------------------------------------------------------17
2.11 Injectors - pressure table: PIXEL 25 FC ---------------------------------------------------------------------------------17
2.11.1 Gas pressure - Heat diagram-------------------------------------------------------------------------------------17
3. MAINTENANCE INSTRUCTIONS------------------------------------------------------------------- 18
3.1 Introduction ---------------------------------------------------------------------------------------------------------------------18
3.2 Circulation deblocking--------------------------------------------------------------------------------------------------------18
4. USER'S INSTRUCTIONS------------------------------------------------------------------------------ 19
4.1 Control panel -------------------------------------------------------------------------------------------------------------------19
4.2 Ignition ---------------------------------------------------------------------------------------------------------------------------19
4.3 Summer mode -----------------------------------------------------------------------------------------------------------------19
4.4 Winter mode --------------------------------------------------------------------------------------------------------------------19
4.4.1 Winter mode with OTC (Outside Control Temperature)------------------------------------------------------------20
4.5 Break down signals -----------------------------------------------------------------------------------------------------------20
4.6 Temporary shut down --------------------------------------------------------------------------------------------------------20
4.7 Long term shut downi --------------------------------------------------------------------------------------------------------20
4.8 Suggestions --------------------------------------------------------------------------------------------------------------------20
4.9 Functioning problems --------------------------------------------------------------------------------------------------------21
Declaration of conformity----------------------------------------------------------------------------------------------------------22
3

1. TECHNICAL DATA
1.1 DIMENSIONS
BOILER L (mm) H (mm) P (mm) A (mm) B (mm) C (mm) D (mm)
PIXEL C 400 720 300 200 200 182 118
1.2 HYDRAULIC SCHEME
1 - gas valve
2 - burner
3 - primary exchanger
4 - circulator
5 - bypass supply
6 - manometer
7 - safety valve (set to 3 bar)
8 - filter
9 - valve of charging supply
10 - vase of expansion
11 - valve in three streets flussostatica
12 - valve of discharging air
13 - sanitary exchanger
14 - condensing exchanger
15 - condensing trap
16 - Fan
1.3 AVAILABLE HEAD
4
L
AB
H
P
CD
4
10
7
6
12
11
13
8
9
5
3
2
1
15
14
16
0
0,5
1
1,5
2
2,5
3
3,5
4
4,5
5
5,5
6
6,5
0 100 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500 1600 1700
Flow rate (l/h)
Available head H (m)
without by-pass
with by-pass

1.4 General layout of the main components of models
PIXEL 25 FC, PIXEL 31 FC
1. Air Pressostat
2. Discharge air valve
3. Primary exchanger limit thermostat (105°C)
4. Flue gas ducts limit thermostat (105°C)
5. Aluminium condensing exchanger Copper
primary exchanger
6. Copper primary exchanger
7. Electrode of lighting and survey
8. Burner
9. Circulator
10.Gas valve
11. Safety valve (3 bar)
12. Condensing trap
13. Supply charge
14. Discharge valve
15. D.H.W. exchanger
16. C.H. sensor
17. Hydraulic three ways valve
18. Sealed chamber
19. Fan
20. Condensate sensor
5
15 17
10
13 14 9
11
12
20
18
16
3
19
8
7
6
1425

1.5 TECHNICAL DATA Size PIXEL 25 F C PIXEL 31 F C
Type C12-C32-C42-C52 C12-C32-C42-C52
Nominal Heat Input to net calorific value (Hi) referred (80 °C /60 °C) KW 25 31
Minimum Het Input to net calorific value (Hi) referred (80 °C /60 °C) KW 10,5 12,4
Nominal Heat Output (80 °C/60 °C) KW 24,4 30,2
Nominal Heat Output Condensing (50 °C/30 °C) KW 26,9 33,3
Minimum Heat Output (80 °C/60 °C) KW 10,1 11,9
Minimum Heat Output Condensing (50 °C/30 °C) KW 10,7 12,6
EfficiencyRendimento (80 °C/60 °C) % 97,6 97,5
Partial Load efficiency (30 % of Pn) % 108,7 107,9
Nominal Heat Input (Pn) gas flowrate Natural gas G20 (2E+) m3/h 2,643 3,278
Natural gas G25 (2ELL) m3/h 3,0745 3,812
LPG G30 (3+) kg/h 1,970 2,443
LPG G31 (3P) kg/h 1,941 2,406
Net gas pressure Natural gas G20 (2E+) mbar 20/25 20/25
Natural gas G25 (2ELL) mbar 20 20
GPL G30 (3+) mbar 29 29
LPG G31 (3P) mbar 37 37
Pn flue gas temperature (80 °C / 60 °C) °C 70 74
Pn flue gas temperature (50 °C / 30 °C) °C 47 51
CO2(G20) % 8 8
NOx (according par 6.2.2 of EN 483) mg/KWh 190 (classe 2) 190 (classe 2)
Losses of heat to the cheminey with burner ignited % 2,8 3,0
Losses of heat to the cheminey with burner not ignited % 0,2 0,1
Losses of heat to the cover (∆T = 50 °C) % 0,5 0,5
Flue gas flow rate Nm3/h 42,09 53,03
CENTRAL HEATING
C.H. Minimum Set point °C 35 35
C.H. Maximum Set point °C 90 90
Volume of water in the boiler l 1,2 1,2
Volume of water of the expansion vessel l 7,5 7,5
Pressure of the expansion vessel bar 0,7 0,7
Least pressure in the primary circuit bar 0,4 0,4
Maximum pressure in the primary circuit bar 3 3
Maximum content of heating water l 150 150
Available head at 1000 l/h of flow rate mbar 230 330
DOMESTICAL HOT WATER
Minimum set point °C 30 30
Maximum set point °C 60 60
Production continuous warm water (T = 25 °C) l/min 14 17,3
Production continuous warm water (T = 35 °C) l/min 10 12,4
Water Volume(T = 30 °C during the first 10 minutes) l 116,6 144,3
Minimum flow l/min 2,5 2,5
Maximum pressure bar 8 8
Minimum pressure bar 0,5 0,5
Voltage l ---- ----
Frequency V/Hz 230/50 230/50
Absorbed eletric power W 150 150
CONNECTION
Flow connection C.H. Inch 3/4" 3/4"
Flow connection D.H.W. Inch 1/2" 1/2"
Gas connection Inch 3/4" 3/4"
Height mm 720 720
Depth mm 300 300
Width mm 400 400
LENGHT OF FLUE GAS DUCTS
Ø 60 x 100 mm coaxial m 4 4
Ø 80 mm doubled m 30 30
Ø 60 mm doubled m ---- ----
Weight Kg 43 43
Degree of protection IP X4D X4D
CE certification 0068 0068
6

1.6 PIXEL FC: ELECTRICAL SCHEME
7
PHASE
NEUTRAL
GROUND
FUSE:
2 x 3,15 AF 5x20 - 250 V
PUMP
FAN
GAS VALVE
N
L
N.O.
C
SUPPLY SENSOR
DHW MICRO SWITCH
P1
P3
P2 TRANSDUCER OF
PRESSURE OF HEATING
SYSTEM
AMBIENT
THERMOSTAT/REMOTE
CONTROL (OPTIONAL)
AIR PRESSOSTAT
3
1
GAS VALVE MODULATOR
ELETTRODE OF LIGHTING
AND SURVEY
EXTERNAL SENSOR
CONDENSATE SENSO
R
Primary exchanger limit
thermostat (105°C)
Flue gas ducts limit
thermostat (105°C)
DHW SENSOR

1.6 PIXEL FCR: ELECTRICAL SCHEME
8
DHW
HEATING SYSTEM
3 WAYS VALVE
EXTERNAL SENSOR
ELECTRODE OF LIGHTING
AND SURVEY
GAS VALVE MODULATOR
1
3
AIR PRESSOSTAT
AMBIENT
THERMOSTAT/
REMOTE CONTROL
(OPTIONAL)
TRANSDUCER OF
PRESSURE OF HEATING
SYSTEM
P2
P3
P1
SUPPLY SENSOR
DHW SENSOR (OPTIONAL)
LN
GAS VALVE
FAN
PUMP
FUSE:
2 x 3,15 AF 5x20 - 250 V
GROUND
NEUTRAL
PHASE
Flue gas ducts limit
thermostat (105°C)
Primary exchanger limit
thermostat (105°C)
CONDENSATE SENSOR

2 INSTALLATION INSTRUCTIONS
2.1 DIFFERENT VENTING OPTIONS:
PIXEL 25 FC, PIXEL 31 FC
Sealed chamber heaters do not require particular caracteristics as for siting and installation are concerned.
Take particular attention to discharge and aspiration unions in order to avoid combustion product leakage.
Use only original spare parts.
The boiler has to be connected to flue gas ducts coaxial or doubled that must desccharge to the outside.
Without them the boiler must not be do to work.
For condensing ARCA boilers you must use only original accessories.
ARCA have also a polipropilene version of flue gas ducts with resistance to the temperature of 120°C
in continuous regime
ARCA have not responsibility for every violation to the recommendations that are in this book and
particularly those related to the unloadings smoke.
2.1.1 Different venting options - Flue Venting
1. Coaxial vent through the roof
2. Coaxial through the wall
3. Split type venting between two cheminey
4. Split type, discharge into a cheminey, fresh air
from outdoor wall
5. Coaxial, connection
with coaxial cheminey
CAUTION! - Follow local regulations concerning draught terminals location from windows and doors.
Note: due to the high efficiency of these boilers a plume of water vapour will form art the flue
terminal during the operation.
9

2.1.2 LENGTH OF FLUE GAS DUCT:
PIXEL 25 FC
2.1.2.1 SPLIT FLUE
Ø 80 mm
N.B.: The flue and aspiration
duct lenght has not to exceed
30 m.
By 0 to 2 m you must put
a Ø 42 mm diaphragme in
the outlet of the fan.
For every added 90° elbow the
maximum allovable lenght is to
be diminuished by 2 m.
The pipes of aspiration and unloading
must be climbed on upward with
inclination of 3° so that the
condensing product flows into the
boiler rather than to the outside.
2.1.2.2 COAXIAL FLUE
Ø 60 x 100 mm
N.B.: The allowed lenght
of coaxial flue ducts is by
a minimum 0,5 meters to
a maximum of 4 meters.
By 0 to 1 you must put a
Ø 42 mm diaphragme in
the outlet of the fan.
The ducts must be
climbed on with light
inclination toward the
outside.
The pipes of aspiration and unloading
must be climbed on upward with
inclination of 3° so that the
condensing product flows into the
boiler rather than to the outside.
10
175
MAX 15 m +
MAX 15 m
105 120
STRAIGHT ON
MAX 15 m
MAX 4 m
143 171
314
MAX 4 m
100

2.1.3 LENGTH OF FLUE GAS DUCT:
PIXEL 31 FC
2.1.3.1 SPLIT FLUE
Ø 80 mm
N.B.: The flue and aspiration
duct lenght has not to exceed
30 m.
By 0 to 2 m you must put
a Ø 42 mm diaphragme in
the outlet of the fan.
For every added 90° elbow the
maximum allovable lenght is to
be diminuished by 2 m.
The pipes of aspiration and unloading
must be climbed on upward with
inclination of 3° so that the
condensing product flows into the
boiler rather than to the outside.
2.1.3.2 COAXIAL FLUE
Ø 60 x 100 mm
N.B.: The allowed lenght
of coaxial flue ducts is by
a minimum 0,5 meters to
a maximum of 4 meters.
By 0 to 2 m you must put
a Ø 42 mm diaphragme
in the outlet of the fan.
The ducts must be
climbed on with light
inclination toward the
outside.
The pipes of aspiration and unloading
must be climbed on upward with
inclination of 3° so that the
condensing product flows into the
boiler rather than to the outside.
11
175
MAX 15 m +
MAX 15 m
105 120
STRAIGHT ON
MAX 15 m
MAX 4 m
143 171
314
MAX 4 m
100

2.2 BOILER PLACING
Follow these instructions:
• having considered the boiler dimensions, fix the dimension plate by means of two hook screws;
• make two holes on the dimension plate holes by means of two hook screws;
• fix all terminal pipes such as cold and hot water pipes, system inlet and return pipes, gas pipes and
electrical cables into their proper holes on the dimension plate inferior part;
• after this it is possible to take away the dimension plate and use it other times;
• hang the boiler through the previously set expansion hooks;
• for the hydraulic connections screw iron-copper joints together with previously set connections. Cut
forwarded pipes according to the distance between boiler joints and iron-copper connections that are
placed on the wall;
• tighten them firmly and control there are no losses.
N.B.: please, remember of taking lead plastic coverings away
12

2.3 HYDRAULIC CONNECTIONS
Domestic water
Supply net pressure is to vary from 1 to 6 bar. Install a reduction in case of higher
pressure. Supply water strenght influences the cleaning frequence of the exchange
serpentine pipe. The possibility of installing water treatment adequate appliances depends
on water caracteristics.
System loading
Slowly open the loading cock up to reaching about 1 bar system pressure, which can be
controlled through the pressure gauge situated on the facial panel. Close the evacuation
cock again.
Make the radiator air bleed using the proper manual valves.
When the system is cold set the system temperature at 1 bar.
In case of installation of the boiler in local
where the temperature environment can
go down below 0°C, we recommends you
to fill the heating system with antifreeze
solution.
You advises to use solutions of glicole
already diluted for avoiding the risk of
uncontrolled dilutions.
ETHILIC
GLYCOLE (%)
FREEZING
TEMPERATURE (°C)
6 0,00
10 -3,90
15 -6,10
20 -8,90
25 -11,70
30 -15,60
40 -23,40
50 -35,50
Suggestions and advice to avoid system vibrations and noises.
• avoid the use of pipes with reduced diametres;
• avoid the use of bends with reduced radius;
• it is better to have a hot system cleaning in order to eliminate all the impurities coming from pipes and
radiators - particularly oil and fat substances - which might damage the circulating pump.
e dai radiatori (in particolare oli e grassi) che rischierebbero di danneggiare il circolatore.
2.4 ELECTRIC CONNECTIONS
The boiler is set to work with a 230V / 50Hz single-phase tension. Connections have to be effectuated by
means of proper cables which come out of the boiler.
There is also an external cable for the ambient thermostat. Connect the thermostat after having eliminated
the jumper on the T.A cable terminal.. ( ATTENTION: the T.A. connection works by net tension; therefore,
you should use plastic models or if they are made by metal you shuold connect them to an efficient earth
system).
The boiler connection has to be protected by means of a 2 pole isolator and a proper fuse (1A).
The appliance has to be connected to an efficient earth system.
Follow present local regulations about safety.
N.B.: respect the phase and neutral position: an eventual inversion of these two positions results in a block of
the ignition panel.
N.B.: ARCA srl declines every kind of responsability for damages to persons, animals or things caused by
the lack of a proper earth system connection and local regulation attention.
13

2.5 GAS CONNECTION
Effect it I lace respecting the norms of the country meticulously.
Making sure that the pipeline of the gas has an adequate in operation section of his length.
Before effect the connection check that the characteristics of the distributed gas are equal you to those bring
on the dataplate of the boilerif these differs is necessary new regulations.
Insert a faucet of interception between the net of feeding of the gas and the boiler.
Open doors and windows and avoid the presence of free flames.
Clean the air contained in the plant tuba-uncle-ni-apparatus.
With the out boiler check that they there are not escapes of gas.
In these conditions observe the gas meter counter for at least 10 minutes for verify that it doesn't signal any
pas-wise of gas.
Verify, in each case, all the line of gas with a solution or equivalent product.
CAUTION!: For running with LPG is necessary the installation of a reduction gear of pressure awry of the
boiler.
1 -Presa pressione
bruciatore
2 - Presa pressione gas di
rete
3 -Vent
A -Vite regolazione
pressione minima
B - Dado regolazione
pressione massima
C- Cappuccio di
Protezione
To perform the control of the pressures to the burner, to insert the probes of the manometer in the available
takings of pressure on the valve gas (you see fig.).
N.B. check that the pressure and the course of the gas of net are enough to guarantee the correct
operation of the instrument to perform the measure to power on burner.
14
2
1
3

2.7 SETTING OF CONTROL PANEL
You can set 4 ways of operation:
a) Normal mode:
Mode of functioning of the boiler, temperature of supply, level of gas modulation and presence of flame are visualised.
Possible anomalies are visualized as besides from coding at page 21.
b) Mode of visualization of boiler parameters:
It is activated by pushing P1+P2 for 6s. You can visualize in order:
Heating set
- supply temperature
Domestical hot water set
- domestical hot water temperature
- water supply pressure
- heat of ignition
- nominal heat output
c) Mode of parameters setting:
It is activated by pushing P1+P2 for 9s. You visualise alternatively the number of the parameter Px and the current value.
Pushing the keys P3 and P4 is possible to see in sequence the modifiable parameters, otherwise with the keys P5 and
P6 it is possible to modify its value.
Pressing P3+P4 you can go out of the function without memorizing the changes.
Pressing P2 for 5s you go out the menu and you memorize the changes.
The available parameters are:
- P1 Power of ignition (by 0 % to 99 % of maximum value of range of regulation)
- P2 Power of heating (by 0 % to 99 % of maximum value of range of regulation)
- P3 Heating anti cycling timer (by 0 % to 99 % of 6 minutes)
- P4 oF = post-ventilation of fan off / on = post ventilation of fan on
- P5 Off = metano / on = GPL
- P6 oF = water's lack: boiler stops / on = water's lack: boiler doesn't stop, but you have to call to call service
assistance.
- P7 Minimum heating input (0 ÷ 100 %)
- P8 oF = external sensor off / on = external sensor on
- P9 K OTC(0 ÷ 6)
- Pa type of boiler (0 = domestical hot water and heating system boiler without tank and with 2 sensor/ 1 =
domestical hot water and heating system boiler with tank and with 2 sensor or only
heating system boiler with tank/ 2 = domestical hot water and heating system boiler
without tank or only heating system boiler without tank and with 1 sensor
- Pb type oh DHW exchanger oF = with plates /on = with little tank
- Pc miminum of heting supply temperature. (+15 ÷ +50) °C
- Pd temperature of primary circuit of tank (0: temperature of primary circuit = DHW set point
+20°C /1: temperature of primary circuit = 80°C)
d) Mode of visualisation of historical failure.
It is activated by pushing P1+P2 for 12s. You visualize alternatively the number of index failure(look at page 21).
By pushing P3+P4 you go out of the function.
By pushing P2 for 5s you can delete the historical of failure.
PRESETTING OF PARAMETERS
I parametri sopraelencati sono pre impostati come segue:
Power of ignition P1 RANGE SUGGESTED VALUE
Heating power P2 0 ÷ 100 30
Anti cycling timer P3 0 ÷ 100 60
Post ventilation P4 0 ÷ 10 7
Natural gas/LPG P5 On/Of On
Water’s trouble P6 On=metano/Of=GPL On=metano/Of=GPL
Minimum heating power P7 On/Of Of
External probe P8 0 ÷ 100 10
K OTC P9 On/Of Of
Type of boiler Pa 0 ÷ 6 3
Type of DHW exchanger Pb 0/1/2 2
Minimum heating temperature Pc On/Of Of
Temperature of of primary circuit of tank Pd +15 ÷ +50 35
0/1 0
To increase the cyclic efficiency we suggest to set P3 (anti cycling timer) with values near to 10 and to set P7 with values
between 10 to 20.
15

2.7. ADJUSTMENT INSTRUCTIONS: NOMINAL HEAT AND
MINIMUM HEAT
The boilers are set you set in our factory and they are predisposed for working with the type of gas of the
data plate.
Check the values of pressure min/max however in how much not all the nets distribute the pressure nominal
gas, value on which the instrument has been regulated in factory.
Check and eventually correct the thresholds of setting to proceed in the following way.
 Insert a manometer for gas on the taking of pressure" 1";
 Turn on the boiler withdrawing the maximum course of sanitary water;
 Make sure that the spool of modulation is fed.
2.7.1 NOMINAL HEAT ADJUSTMENT
1. Turn on the boiler withdrawing the maximum flow of domestical water;
2. Make sure yourself that the spool of modulation is fed;
3. Remove the hood of protection" C";
4. Adjust the maximum pressure acting on the die" B" with the aid of a key from 10 mms; rotating clockwise the
pressure increases, rotating counterclockwise in sense the pressure decreases;
2.7.2 MINIMUM HEAT ADJUSTMENT
1. Set the boiler on “Winter” position (see at page 21);
2. Close the contact of ambient thermostat if you have it;
3. Set heating regulation at maximum;
4. Set heating power at maximum (see at page 21).
5. Rotate the red die" Á." up to the attainment of the suitable least pressure on the book (clockwise it increases, in
sense counterclockwise it decreases);
6. Put again the hood of protection" C."
7. For the values of regulation of the heating power of the boiler see at page 18
8. Withdraw the maximum flow of sanitary water to verify the pressure of the maximum heat.
Remember to always close the takings of pressure after the use and to verify its correct estate
2.8 SLOW IGNITION AND NOMINAL HEAT ADJUSTMENT
2.8.1 SLOW IGNITION ADJUSTMENT
The boiler is delivered already set to the following values:
MET = 30 mm H2O
LPG = 80 mm H2O
Follow these instructions if you have to change these values:
• open the domestic water to its maximal level and turn the boiler off;
• turn the boiler on;
• check the pressure of the gas to the burner during the cycle of ignition (the pressure of slow ignition is actually
maintained to the relevation of the flame).
• push for 6 sec P1 and P2 and see c) “Mode of parameters setting” (look at page 18)
Set P2 as you need.
• To reset the value of slow ignition you need to turn off the boiler, to again act on the parameters and to remake
ignitionr verifying the attainment value of desired pressure.
ATTENTION: the slow ignition time for its adjustment is 5 seconds after which the nozzle pressure will increase or
decrease according to the energetical need. If a further change is needed repeate this operation by turning the boiler on
and off.
2.8.2 NOMINAL HEAT ADJUSTMENT
The greatest heating power has to be adjusted according to system needs.
Gas pressure values are shown at page 18 in the table “INJECTORS PRESSURE TABLE”.
For the adjustment of the burner gas pressure follow these indications:
• Set the boiler on “Winter” position;
• create a jumper on the ambient thermostat in order to start the boiler;
• push for 6 sec P1 and P2 and see c) “Mode of parameters setting” (look at page 15)
Set P1 as you need.
N.B.: wait about 10 seconds to allow the pressure stabilisation after the slow ignition.
2.9 DIFFERENT GASES
This is a LPG or natural gas boiler as well. The transformation from one gas type to the other one has to be carried out
as follows:
Transformation from methane to LPG gas
• replace burner injectors
• change the JP1 jumper position and set it to “LPG” position (see the electrical scheme);
• adjust MIN/MAX pressure levels keeping in mind the above shown instructions;
• as far as the injectors diametres and the burner gas pressure are concerned, see the above table;
16

• after this seal the valve regulator by means of a coat drop.
Transformation from LPG to methane
• replace burner injectors;
• change the JP1 jumper position and set it to “METHANE” position (see the electrical scheme);
• adjust MIN/MAX pressure levels keeping in mind the above shown instructions;
• as far as the injector diametres and the burner gas pressure are concerned, see the above table;
• after this seal the valve regulator by means of a coat drop.
2.10 INJECTORS PRESSURE TABLE:PIXEL 25 F C
Injectors diameters Gas diaph. Burner pressure
P.C.I Inlet
pressure Quantity Ø Ø Min. Heat = 10,5
KW
Qnom. =
25 KW
TYPE OF GAS
MJ/m3 mbar n° mm mm mbar mbar
NAT.GAS G20 (2H+) 34,02 20 13 1,20 5,5 1,5 11,3
NAT.GAS G25 (2H+) 29,25 25 13 1,20 5,5 2,4 14,3
NAT.GAS G25 (2LL) 29,25 20 13 1,30 ------- 1,3 12,7
NAT.GAS G25.1 (2HS3B/P) 29,21 25 13 1,30 ------- 1,8 13,3
BUTANE G30 116,09 28/30 13 0,72 ------- 5 27
PROPANE G31 88 37 13 0,72 ------- 6,2 34,6
2.11 INJECTORS PRESSURE TABLE:PIXEL 31 F C
Injectors diameters Diafr. Gas* Gas diaph.
P.C.I Inlet
pressure Quantity Ø Ø Min. Heat = 12,4
KW
Qnom. =
31 KW
TYPE OF GAS
MJ/m3 mbar n° mm mm mbar mbar
NAT.GAS G20 (2H+) 34,02 20 13 1,30 6,5 2 13,2
NAT.GAS G25 (2H+) 29,25 25 13 1,30 6,5 2,8 16,2
NAT.GAS G25 (2LL) 29,25 20 13 1,45 ------- 1,4 10,8
NAT.GAS G25.1 (2HS3B/P) 29,21 25 13 1,45 ------- 1,5 12,2
BUTANE G30 116,09 28/30 13 0,8 ------- 4,3 27
PROPANE G31 88 37 13 0,8 ------- 6,1 34,9
* Only for France and Belgium
17
2.10.1 Gas pressure - Heat diagram
8
10
12
14
16
18
20
22
24
26
0 5 10 15 20 25 30 35
Burner pressure (mbar)
NOMINAL HEAT
(KW)
NAT.GAS. H (G20)
NAT.GAS L (G25)
NAT.GAS. LL (G25)
NAT.GAS G25.1
(II2HS2B/P)
BUTANE (G30)
PROPANE (G31)
2.11.1 Gas pressure - Heat diagram
10
12
14
16
18
20
22
24
26
28
30
32
34
0 5 10 15 20 25 30 35 40
Burner pressure (mbar)
NAT.GAS H (G20)
NAT.GAS L (G25)
NAT.GAS LL (G25)
NAT.GAS G25.1
(II2HS2B/P)
BUTANE (G30)
PROPANE (G31)

3. MAINTENANCE INSTRUCTIONS
3.1 INTRODUCTION
All the maintenance and gas transfomation operations have to be carried out by qualified
personnel.
Moreover, MAINTENANCE operations have to be made at least once a year and
according to local regulations.
Before winter it is necessary to make the boiler be controlled by authorised personnel to
have an always working system.
Control:
• verify the exchanger cleaning;
• verify the burner cleaning;
• verify the hydraulic system pressure;
• verify the expansion vessel heating system efficiency;
• verify the correct functioning of adjustment and safety thermostats;
• verify the cleaning and integrity of sensor and ignition electrodes;
• control the good circulator running;
• control there are no spills (water, gas smoke evacuation);
• control the gas burner pressure;
• control the combustion output;
• control the emission levels of CO, CO2and NOX;
• in case of a boiler spare part replacement you should use only original spare parts by
ARCA.
Arca refuses every kind of responsability about every damage caused by the installation of
a non original spare part.
ATTENTION: this boiler has a safety thermostat linked to the chimney draught which starts
to work when there is a combustion product coming back in the ambient. This appliance
has never to be placed out of work. If combustion products come back in the ambient, they
can cause severe intoxications with even death risks.
ATTENTION: after any boiler service regarding the gas pipe system it is absolutely
necessary to control that unions are perfectly running and there are no gas spills.
3.2 CIRCULATION DEBLOCKING
When the boiler is new or after a long standstill period you may have a circulator block.
You can comply with this problem as follows:
• unscrew and remove the circulator cap;
• insert the screwdriver and turn it to deblock the circulator;
replace the cap.
18

4. USER’S INSTRUCTIONS
4.1 CONTROL PANEL
Thermometer:
Through the
thermometer it is
possible to verify the
temperature of run of
the circuit of heating,
previously planned
through the relative
regulator.
Manometer:
It visualizes the pressure
of the heating water; the
value of such pressure
doesn't have to be
inferior to
0,8. 1 bar (cooled down
circuit).
If the pressure had to be
inferior to
\ \0,8. 1 bar (cooled down
circuit).
,
it is necessary to handle
the restoration of the
correct value acting on
the charge valve. This
operation must be
performs cooling down
circuit.
.
Regulator temperature
domestical water:
The function of this handle
grip is to fix the value of
the temperature of use of
the domestical water;
acting counterclockwise in
sense the lowest value of
the temperature
impostabile is gotten
Regulator
temperature of heating:
Through this handle grip it is
possible to plan the
temperature desired of the
circuit of heating:
acting counterclockwise in
sense the lowest value of
the available temperature is
gotten
Summer Winter Reset
With the changer in position
Summer the boiler is
predisposed to run for the
onlyproduction of domestical
water.
With the changer in position
Winter the boiler is
predisposed to run both for
the heating that for the
production of domestical
water.
Bring the selector in
position of Rearmament
to reactivate the
operation of the boiler
after the intervention of
the device of block of
the burner.
4.2 IGNITION
Open the manual gas supply line cock, located outside of the boiler. Push to the SUMMER or WINTER position: the
boiler should ignite automatically. If the boiler does not ignite you will see a failure in the display.
4.3 SUMMER MODE
For domestic hot water only.
Push MENU to SUMMER position. Set the domestic water temperature adjustment to the desired setting. The domestic
hot water production is activated.
4.4 WINTER MODE
For heating mode and domestic hot water mode.
19

Push MENU to WINTER position. Set the heating temperature adjustment to the desired setting. Room thermostat will
keep the desired value.
4.4.1 WINTER MODE with OTC (Outside Temperature Control)
It’s activated through the connection of the probe of external temperature and the setting of the parameter (mode of
parameter setting).
The operation is the same of heating mode, with the difference that supply heating temperature is calculated in
combination with the external temperature from the external probe and from the factor K (set between 0 and 6 by mode
of parameter setting).
Below you can see a graph of the OTC function (minimum set point of heating supply temperature = 15°C).
The regulation of the ambient temperature can be made only by compensation of supply temperature with the external
temperature or in combination with the remote control (look at instruction manual of remote control).
The correction of the temperature in of heating supply is made every minute with a function of reduction of the sudden
variations.
In case of breakdown to the probe it expresses the regulation of the temperature supply it is made though pulsating sets
heating with the same functions described in the previous paragraph.
4.5 BREAK DOWN SIGNALS
CODE DESCRIPTION
01 LOCKOUT due to not ignition/condensate sensor
02 Failure of heating system pressure 1
03 Failure of external sensor
04 Failure of heating sensor
05 Failure of DHW sensor
06 LOCKOUT due to high temperature/exceeding of flue gas temperature
08 Air pressostat failure/flue gas thermostat
09 Not water circulation
4.6 TEMPORARILY TURNING BOILER OFF
You can achieve it by means of:
- the room thermostat ;
- the MENU on the instrument panel;
4.7 LONG TERM SHUT DOWN
If the boiler is to remain off for a long period of time, close the gas cock to the boiler. Before start- up, manually turn the
rotating part of the circulator pump in case it froze (slightly stuck) during the down time.
4.8 SUGGESTIONS
Once a year the boiler should be cleaned and checked to make sure that all components are working properly. Do not
adjust the gas valve, this is to be done only by a licensed authorized technician.
If there is a lockout, turn knob to reset position. If the problem happens often, call a licensed authorized technician.
The condensing must not be modify or closed.
After a long period of inactivity verify the presence of water in the condensing trap verifying if after the burner restart, in
10 minutes condensing water start to descharge out of the condensing trap.
If this doesn't happen, please call a center assistance authorized ARCA srl.
20
1Anomaly is visualized and prevented the starting the burner for P < 0,25 bar. The starting of the burner is allowed for P > 0,4 burner
Subsequently to anomaly the burner starts correctly working after the pressure of heating system is corrected. To return to the normal
visualization press the P2 button.
Through parameter P6 is possible to start the burner however even if it foresees anomaly pressure plant, that comes all the same
visualized.
0 - 5 - 10 - 15
5
101520
K=3
K=4
K=6
setpoint(°C)
E xternal tem perature (°C )
90
80
70
60
50
40
30
20
10
25 - 2 0 - 2 5
K=2
K=1