Unical DUA plus, Installation And User Instruction Manual

Page: 29 / 32

29
Service info
3.3 - IMPORTANT
SUGGESTIONS
AND NOTES
According to the national laws the service of
the heating appliances is compulsory.
This service consistes, as a minimum, of an
annual systematic visit, during which the
serviceman will control the safety equipment
and will make the cleaning of the combustion
circuit of the boiler.
This annual visit must be conducted within
the frame of a service contract, whose
different variants can include all or part of
the interventions concerning the
deplacement, the manpower and the spare
parts.
Only persons professionally qualified can
perform interventions on the gas valve
adjustment.
Check regularly the filling pressure of the
heating system through the manometer, and,
if necessar y, reinstate the minimum
pressure value (0.8/1 bar in cold condition).
When the boiler stays without been used for
a long period, before putting the boiler in
operation make sure the pump is not jamed.
To make it free, if necessary, remove the
plug on the motor axis, put a screwdriver in
the slot foreseen on the motor shaft end and
try to rotate it manually, clockwise.
Once this dejamming operation has been
concluded, replace the protecting plug and
make sure there are no water leaks.
This operation has to be made,
preferably, by the Unical Service Center
charged for maintenance of the boiler.
The hardness of the domestic water
conditions the frequency of the cleaning of
the coil heat exchanger.
The convenience of water treatment must
be examined on the base of the water
characteristics.
N.B. If the water hardness is higher than
20°f (french), the adoption of a water softer
is strongly recommended.
FROST PROTECTION
If the boiler is connected to the mains and
the main switch "A" is in the antifrost position,
the heating pump is put into operation, for a
few seconds, every day, in order to impede
the pump jamming.
The boiler is equipped with an automatic
antifrost protection system: this system is
operational when the temperature detected
by the flow temperature sensor falls below
7°C by switching on the heating pump.
Below 5°C, the burner and the pump are
switced on, untill the temperature of 15°C, is
reached with a 15 min. maximum time limit.
After that, burner and pump are swiched off.
This cycle will be repeated, if necessary.
3.2 - IGNITION AND
EXTINCTION
BOILER IGNITION
Position the main switch "A" on "I" position .
SUMMER mode
(D.H.W.production only)
Select the SUMMER operation mode acting
on the selector "B".
Turn the temperature adjusting knob "D" on
the desired value.
By CLOCKWISE rotation the maximum
temperature is achieved.
WINTER mode
(Heating and D.H.W. production)
Select the WINTER operation mode acting
on the selector "B".
Turn both, the heating temperature adjusting
knob "C" and the D.H.W. temperature
adjusting "D" on the desired values.
By CLOCKWISE rotation the maximum
temperature is achieved.
HEATING mode
(Heating only is activated)
Select the HEATING only operation mode
acting on the selector "B".
Turn the temperature adjusting knob "C" on
the desired value.
By CLOCKWISE rotation the maximum
temperature is achieved.
The boiler gives always the priority to the
D.H.W. mode (see SUMMER operation).
Once the D.H.W. demande is satisfied, if the
room thermostat asks for heat, the boiler
goes to HEATING mode.
During the heating operation mode the boiler
switches ON and OFF controled by the
room thermostat and by the electronic P.C.B.
of the panel board.
The electronic control built-in the panel
board, depending on the detected
temperature difference between the one
adjusted on the knob and the one mesured,
puts the burner into operation plus or minus
frequently in order to satisfy very quickly
the heat demande by the room thermostat.
ANTIFROST mode
Select, by acting on the selector " B " the
position (Antifrost)
NB: The signal lamp "H" is ON. .
COMPLETE EXTINCTION OF THE
BOILER
Cut the elctrical power supply to the boiler
acting on the main switch
"A" (position O ).
If, for any reason (lack of gas or electricity),
the antifrost protection system does not
work and the temperature detected by the
flow temperature sensor falls below 2°C, the
operation of the burner is automatically
inhibited until the detected temperature rises
above 5°C.
This system protects the boiler and the even-
tual DHW tank from freezing, but it does not
protect the C.H. and sanitary circuits.
Moreover special anti-freeze products sui-
table for the multimetal installations can ef-
fectively protect the heating system from the
freeze.
Do not use the anti-freeze products for
car's engines because they can damage
the water sealing gaskets.
Note
The anti-freeze protection device system
will start running only if both the electrical
and gas supply of the boiler are left
connected.
Information for the user
The user can gain access only to the
parts of the boiler which can be reached
without the need of tools.
It is therefore forbidden to disassemble
the outer casing of the boiler and tam-
per with the internal parts.