1.2. How the heating unit operates
1.2.1. Start-up
- Turn on the fuel tap;
- turn the power switch external to the heating unit to ON;
- turn the heating unit main switch 16 (pic.1) to ON (the switch
lights up);
- select the heating unit operating mode through knobs 11, 12
and 13, and the programmable timer when installed (refer to
1.2.2 paragraphs from 1.2.2 to 1.2.3);
- set desired room temperature through the room thermostat
(when available);
- when the system requires heat, CH request led 10 (pic.1)
comes on;
- when the burner is ON, led 3 is on (the light turns on when
electric power is supplied to the burner, and it does not
necessarily indicates that a flame is present).
N.B.
On models 23 and 33 the burner is equipped with an oil pre-
heating device (always active). Therefore a waiting time of
up to three minute might be necessary prior to actual flame
presence, depending on the temperature of the oil.
In B and BV models and R and RV models equipped with
external cylinder (optional equipment), the DHW supply and
temperature maintenance function has always priority over
CH function
1.2.2. Operation
Heating units are divided into two main families:
a) heating unit serving an high temperature CH zone + DHW
supply (B and R* models);
b) heating unit serving a mixed water CH zone, an high tempe-
rature CH zone + DHW supply (BV and RV* models)
1.2.2.1. Management of a heating unit serving an high tem-
perature CH zone + DHW supply (B and R models)
(*) In R and RV models, DHW supply and related functions
are operated only when an external cylinder is connected
(optional equipment), for which the ANTI-LEGIONELLA fun-
ction is not active.
Set button 16 to position I: power is supplied to the heating unit
and the button light is ON.
Knob 11 is to select the heating unit operation mode. In detail:
“timer”
position ( to be used when programmable timer 15
is installed).
All functions are active: (CH, DHW (*), ANTI-FROST, PUMP ANTI-
LOCKING, ANTI-LEGIONELLA).
In this position the heating unit operates following the programs
of the two channel programmable timer 15. The user manages
CH through channel 1 (see CENTRAL HEATING); The user ma-
nages DHW supply through channel 2 (see DOMESTIC HOT WA-
TER);
- CHANNEL 1 without external probe
When the contact is OFF, CH is OFF. When the contact is ON,
CH is managed through the room thermostat.
- CHANNEL 1 with external probe
See 1.2.2.3 “SLIDING TEMPERATURE” paragraph operation.
- CHANNEL 2
When the contact is OFF, DHW production is not active, DHW
is supplied at domestic cold water network temperature. When
the contact is ON, the cylinder is kept to the temperature set by
knob 12b (B and BV models), or through the adjustable thermo-
stat on the cylinder. Temperature range is 35°C – 65° C in B and
BV models, in R and RV models it is depending on the type of
cylinder (optional equipment).
The programmable timer 15 allows for setting of up to 8 ON daily
programs and 8 OFF daily programs.
Detailed programmable timer setting procedure is available in
1.2.3 paragraph.
N.B.
When neither the programmable timer nor the external pro-
be are installed, the position manages the “Summer”
function (see below).
When the programmable timer is not available, and the ex-
ternal probe is installed, the position manages the “night”
function (see below).
“Comfort”
position.
All functions are active: (CH, DHW (*), ANTI-FROST, PUMP ANTI-
LOCKING, ANTI-LEGIONELLA).
Channel 1 of the programmable timer (when available) is con-
sidered always ON regardless of the set program, therefore CH
function is managed by the room thermostat or thermoregula-
tion control unit (when they are available).
Detailed information about
“Comfort”
position with external
probe are available in 1.2.2.2 paragraph “Management of a hea-
ting unit serving an high temperature CH zone + DHW supply (B
and R models)” and 1.2.2.3 paragraph “SLIDING TEMPERATU-
RE” operation.
DHW (*) function is managed through knob 12b, by the adjusta-
ble thermostat on the cylinder (R and RV models), and by chan-
nel 2 of the programmable timer (see above described “timer”
position
).
“Night”
position.
When the external probe is not installed, the position mana-
ges the “Summer” function (see below).
The “Night” position is active when an external probe is
installed (see 1.2.2.2 paragraph “Management of a heating
unit serving an high temperature CH zone + DHW supply (B
and R models) and 1.2.2.3 paragraph ”SLIDING TEMPERA-
TURE” operation.
CH function is not active. DHW (*), ANTI-FROST, PUMP ANTI-
LOCKING, ANTI-LEGIONELLA functions are active.
Channel 1 of the programmable timer (when available) is consi-
dered always OFF regardless of the set program, therefore CH
mode is always off in spite of a CH request from the room
thermostat or thermoregulation control unit (when they are avai-
lable).
DHW(*) is set by knob
12b
(B and BV models), or via the adju-
stable thermostat on the cylinder, and by channel 2 of the pro-
grammable timer (see above information about “programmable
timer” ).
“Anti-frost”
position.
Active functions are: ANTI-FROST, PUMP ANTI-LOCKING,
ANTI-LEGIONELLA. The thermal unit is in stand-by mode.
CH flow anti-frost: when the probe detects a temperature below
5°C, the heating unit is turned on until CH flow temperature rea-
ches 50°C or 15 minutes have elapsed.
DHW flow anti-frost (active in B and BV models only): when the
cylinder probe detects a temperature below 5°C, the heating
unit is turned on until the cylinder water temperature reaches
10°C or 15 minutes have elapsed.
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