Technical data
24
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Touch & Go Function: if you don’t wish to keep the Memory
function always enabled or if you need hot water to be ready fast
besides the usual habits memorized, it is possible to perform the
domestic hot water pre-heating only a few moments before the
request.
Due to Touch & Go function, by turning on and off the tap the
instantaneous pre-heating function enables, which prepares hot
water only for that request.
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● Frost-protection: this function is only active when there are no
requests for heating or HW. Should the temperature of the pri-
mary thermistor drop below 7°C, the valve actuator will motor to
the heating position. Should the temperature of the primary ther-
mistor exceed 10°C during this period, the cycle will be aborted.
If the temperature drops below 4°C, the boiler will operate on
minimum power until the temperature of the primary thermistor
reaches 30°C. Thereafter the pump & fan will over-run for 30-
seconds.
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● Pump/actuator anti-block cycle: when there has been no
heating or HW request for 24-hours, the anti-block cycle is
activated. The valve actuator will motor from the DHW position
to the heating position for a period of 10-seconds and then motor
back to the DHW position. Thereafter the pump will be activated
for a period of 1-minute. If the selector switch is in the Heating &
HW position, the fan will also be active for 1-minute.
7.2.7 HEATING MODE
Press the button to select the heating mode: the display will
show boths layers.
The valve actuator will motor to the heating position and the pump
and fan will be activated via the flow temperature sensor. When the
fan is sensed to be operating correctly, the ignition sequence
commences. Ignition is sensed by the electronic circuitry to ensure
flame stability at the burner. Once successful ignition has been
achieved, the electronic circuitry allows 75% 0f the full gas rate
through the appliance. After 15 minutes (adjustable, see parameter
28, cap. 7.3.1) the gas rate is increased to maximum (100%).
The speed of the fan and therefore the output of the boiler is
determined by the temperature of the water sensed by the flow
temperature sensor, consequently a high temperature at the flow
sensor results in a lower fan speed. As the water temperature
increases, the temperature sensors – located on the flow pipe of
the boiler – reduce the fan speed via the electronic circuitry.
Depending on the load, either the water temperature will continue
to rise until the set point is achieved or the water temperature will
fall whereby fan speed will increase relative to the output required.
When the boiler has reached the set point, the burner will switch off.
The built-in anti-cycle device prevents the burner from re-lighting
for an adjustable period of time (factory default is 5 minutes). When
the temperature of the flow sensor falls below the set-point, the
burner will re-light.
NOTE
If the spark/sensing electrode does not sense ignition the appliance
will re-attempt ignition a further 4-times then go to lockout.
When the set-point has been reached (the position of the heating
temperature selector) as measured at the primary thermistor, the
appliance will begin the modulation phase whereby the fan and
gas valve will continuously modulate to maintain the set-point. If the
temperature continues to rise and exceeds the set-point by 6°C, the
burner will shut down. A new ignition sequence will be enabled
when the 5-minute anti-cycle
has been performed and the
temperature at the primary ther-
mistor has dropped 6°C below
the set-point.
NOTES
Any DHW request will always
have priority over the heating
request.
When the request for heating
has been satisfied, the
appliance pump and fan may
continue to circulate to dissi-
pate any residual heat within
the appliance.
7.2.8 DHW MODE
Press the key to select the DHW mode: the display will show
only the DHW layer.
The valve actuator will motor to the HW position (if a heating request
was active) and the pump and fan will be activated via the flow
temperature sensor. When the fan is sensed to be operating
correctly, the ignition sequence commences. Ignition is sensed by
the electronic circuitry to ensure flame stability at the burner.
Once successful ignition has been achieved, the electronic circuitry
modulates the appliance output in order to achieve the DHW set-
point (the position of the DHW temperature selector) as measured
at the DHW thermistor. When the set-point has been reached, the
appliance will begin the modulation phase whereby the fan and gas
valve will continuously modulate to maintain the set-point.
If the temperature continues to rise and exceeds the set-point by
5°C, the burner will shut down until the temperature drops to set-
point + 4°C, whereby a new ignition sequence will be enabled.
If the TSC function is active the set point will be overridden until/
unless the appliance reaches the maximum operating temperature.
When the request for DHW has been satisfied, the appliance fan
may continue to operate to dissipate any residual heat from within
the appliance.
7.2.9 ADJUSTING HEATING TEMPERATURE WITH AN
EXTERNAL PROBE CONNECTED
When an external probe is connected, the value of the delivery
temperature is automatically chosen by the system which rapidly
adjusts the room temperature according to the variations in external
temperature.
The external probe symbol appears on display and just the central
segment of the heating bar lights up.
If you want to adjust the temperature value, by increasing or
increasing it given the value automatically calculated by the
electronic board, proceed as follows:
- press the heating temperature adjustment key
, the number
corresponding to the set comfort level will appear on the two
digits B (standard setting)
- turn the selector A to increase or decrease the comfort level (the
number corresponding to the selected comfort level will appear
on the two digits +1, +2 etc or -1, -2 etc).
The illuminated segment of the heating bar will increase or
decrease. Correction tolerance lies between - 5 and + 5 comfort.
These corrections are very important between seasons, when the
value calculated by the curve could result too low and therefore
the time for reaching the set room temperature could be too long.
After 3 seconds from the last adjustment, the value is automatically
memorized and the display shows again the value recorded
instantaneously by the probe.
Adjusting domestic hot water temperature
- Press the
key and turn the selector A to select desired
domestic hot water temperature. The big digits will light up on
display, indicating the selected temperature value.
After a few seconds the display will show again the delivery
temperature, effectively recorded by the boiler’s probe.
A
B
Fig. 39
Fig. 40