Immergas HERCULES Condensing 26 2 E Manual page 45

Technical Documentation
DHW request.
By pressing the main button (
which is enabled for functioning in the DHW phase.
If the temperature detected by the DHW NTC probe (B2),
positioned on the storage tank, is lower than the setting made
on the control panel (or on the CAR or Super CAR if mounted)
and if the contact of the system pressure switch (S5) is closed
(pressure detected in the primary circuit higher than minimum
value), the integrated P.C.B uses the K2 relay to power the
boiler pump (M1), after which by diversion of the K4 relay
contact it powers the motor (M) of the 3-way valve (M30).
This functions until the end run switch "2" opens when the
DHW position is reached.
Successively the integrated P.C.B. powers the fan (M20) and
manages the speed.
With the consent of the safety thermostat (E4) and the flue
safety thermostat (E6) and the fan (M20) reaching the "validate
ignition" speed, the integrated P.C.B. allows to start the igni-
tion cycle by controlling, first the ignition electrodes (E1) by
means of the K7 igniter relay and then the K3 request relay,
both the coils of the gas valve (Y1).
The ignition of the burner is detected by the integrated P.C.B.
by means of the ionisation electrode (E2).
When the flame has been detected, the fan speed is increased
in a way to immediately reach (if requested) the maximum
adjusted value or that necessary to reach the set temperature.
Successively, flame modulation takes place with reference to
the difference between the temperature set using the DHW
temperature selector switch and the temperature detected by
the DHW probe (B2).
When the temperature measured by the DHW probe (B2)
exceeds the value requested (set temperature), the K3 relay is
opened (burner switch-off) and after the post-circulation time
(60 seconds) also relay K2 (boiler pump). In the meantime
the fan functions and carries out post-ventilation for 35
seconds.
When the temperature of the DHW contained in the storage
tank drops below the value defined and that can be set using
the "DHW OFF" parameter with respect to the temperature
set by the DHW temperature selector switch, the relays are
closed again in order to start a new ignition cycle.
If, during functioning, the flow probe (B1) measures a tem-
perature exceeding 90°C, the contact of relay K3 is opened
(burner switch off) which are closed again when the temperature
drops to 75°C.
Solar function.
With the "DHW OFF" parameter on "OFF2" (DHW set-point
hysterisis 2), the boiler is prepared to receive pre-heated water
from a system of solar panels.
While the water contained in the storage tank is at a tem-
perature above the DHW set-point -10°C, the burner and the
pump remain off.
The boiler is kept in the DHW status, shown on the display.
The boiler activates in the DHW mode only when the tem-
perature of the water contained in the storage tank is below
the DHW set-point -10°C.
STHCkW ed 04/09
) boiler activation is enabled,
Technical Documentation
Central heating anti-freeze request.
When the temperature detected by the CH flow probe (B1)
falls below 4 °C, the board gives consent for ignition and keeps
the generator working with the burner at minimum output
until a boiler temperature equal to 42 °C is reached (radiators
anti-freeze).
The anti-freeze function is not activated if the main boiler
button is selected (Stand-by).
DHW anti-freeze request.
If the temperature detected by the DHW probe (B2) falls
below 4 °C, the board gives consent for boiler ignition and
keeps the generator working with the burner at minimum
output until a temperature of 20 °C is reached. Post-circulation
is then activated in the central heating mode with duration
of 150 seconds.
During functioning, the water in the primary circuit remains
below 42 °C as on reaching this temperature the board switches
the burner off.
If the DHW anti-freeze is activated in concomitance with a
central heating request, the DHW anti-freeze is served for
2 minutes and the central heating request for 6.5 minutes
(continuously).
"Chimney sweep" request.
Press the Reset button "C" for a time between 8 and 15
seconds, on its release the board gives consent for ignition of
the generator and keeps it functioning at maximum heating
output set for 15 minutes.
During this period only the limit thermostat function is
respected (90 °C), which is performed by the central heating
flow probe (B1).
The function is signalled by the relative symbol and the code
"07" on the remote control display (if mounted).
It can be interrupted by pressing the main button (
off position or after 15 minutes have passed.
System deaeration function.
To activate the "DEAERATION" function, press buttons "A
and B" at the same time for 5 seconds with boiler in stand-
by. The function consists in the cyclic activation of the pump
(100 s ON, 20 s OFF) and the 3-way valve (120 s domestic
hot water, 120 s central heating).
The function ends after 18 hours or by switching the boiler
on using the ignition button (
43
) in the
).
HERCULES Condensing Export