3.8 Automatic operating mode
The control automatically activates the heat pump or the alter-
native source to heat pump according to the comparison be-
tween the intake air temperature (S02) and the external air val-
ue set for the activation of the alternative source to heat pump
(parameter H05).
Whereas the electric heating element activation is possible
for all models, the boiler activation is possible only for model
NexPro 300 CS Plus where a suitably dimensioned auxiliary ex-
changer is present.
To activate AUTO mode, press and hold [FUNCTION] key until LED
L19 ashes, then press [SET] key to conrm. LED L19 remains
steady on.
The reference setpoint Ut1 displayed can be changed by pressing
[UP] and [DOWN] keys.
In heat pump mode the following warnings occur:
−if S02 ≥ H05, domestic hot water is produced through the
heat pump. In this case if water temperature ≤setpoint
- differential, i.e. in terms of parameters: S01 ≤ (Ut1-H26),
the heat pump can start. When the setpoint Ut1 is reached
and is kept for a time equal to H22, the heat pump turns
off. LED L19 is steady on
−if the temperature detected by probe S01 is lower than
setpoint Ut1, but the delays set through parameters H20
(minimum time between compressor switching on and
off) and H21 (minimum time between two consecutive
compressor activations) are active, LED L2 will ash to in-
dicate that the compressor is respecting the delay times
−if the heat pump is active and the temperature detect-
ed by probe S01 is lower than setpoint Ut1, LED L2 will be
steady on
−if setpoint Ut1 is reached or exceeded, LED L2 will be off.
If S02 < H05, domestic hot water is produced through the heating
element or the boiler, while the heat pump is forced to switch
off. LEDs L3 or L4 turn on to indicate that the electric heating el-
ement or the boiler, respectively, is operating.
The heat pump is reactivated (with subsequent heating element
or boiler switching off) after 20 minutes, if S02 ≥ H05.
NOTE: in the navigation diagram, near parameter Ho2, it is
possible to see the electric heating element runtime whereas,
near parameter Ho4, it is possible to see the boiler runtime.
3.9 Choice of the alternative energy source to the
heat pump
The activation of the alternative energy source to the heat pump
depends on parameter H50 (default value=0). In automatic
mode, the adjustment is made according to the parameters of
the hot water setpoint Ut1 and the heat pump activation differ-
ential H26. In manual mode, the adjustment is made according
to the parameters of the hot water setpoint Ut2 and the alter-
native energy source to the heat pump activation differential
H28. If parameter H50 = 0, the electric heating element acti-
vates when required. LED L3 is steady on. When the setpoint is
reached, LED L3 is OFF.
If parameter H50 = 1, the boiler activates when required. LED L4 is
steady on. When the setpoint is reached, LED L4 is OFF.
NOTE: in the navigation diagram, the heating element status is
indicated by parameter r2 (1 = active, 0 = not active) whereas
the boiler status is indicated by parameter r7 (1 = not active,
0 = active).
3.10 Manual operating mode
The control activates the electric heating element or the boiler,
according to the value of parameter H50 previously seen. To ac-
tivate MANUAL mode, press and hold [FUNCTION] key until LED
L18 ashes, then press [SET] key to conrm. LED L18 remains
steady on.
Whereas the electric heating element activation is possible
for all models, the boiler activation is possible only for model
NexPro 300 CS Plus where a suitably dimensioned auxiliary ex-
changer is present.
The adjustment is made according to setpoint (Ut2) and heating
element/boiler activation differential (H28) parameters.
If S01 ≤(Ut2-H28) i.e water temperature ≤ (setpoint - differential)
the heating element or the boiler is activated.
If S01 > (Ut2-H28) i.e water temperature > (setpoint - differen-
tial) the heating element or the boiler is switched off.
The reference setpoint Ut2 can be changed by pressing [UP]
and [DOWN] keys.
NOTE: in the navigation diagram, near parameter Ho2, it is
possible to see the electric heating element runtime whereas,
near parameter Ho4, it is possible to see the boiler runtime.
3.11 Fast heating Function
It allows to obtain hot water as quick as possible, but with a
higher energy consumption, by activating simultaneously the
heat pump and the supplementary source selected with param-
eter H50 until the setpoint set is reached.
To activate the FAST HEATING function, press [FUNCTION] key
until LED L17 ashes, then press [SET] key to conrm. LED L17
remains steady on.
The activation is possible only in AUTO mode, whereas it cannot
be activated if ANTI-LEGIONELLA or HIGH TEMPERATURE FUNCTIONS
ARE ALREADY ACTIVE.
The reference setpoint, Ut3, can be changed by pressing [UP]
and [DOWN] keys.
The activation of FAST HEATING function is intended for a single
cycle, therefore when setpoint Ut3 is reached the unit goes back
to AUTO mode.
3.12 Anti-legionella function
This mode performs an antibacterial treatment, that consists in
increasing and keeping the temperature of the water contained
in the tank to the thermal shock temperature (65-70°C) for a
preset time.
To activate ANTI-LEGIONELLA function, press and hold [FUNC-
TION] key until LED L16 ashes, then press [SET] key to conrm.
LED L16 remains steady on.
9 IT is possible to activate/deactivate the antibacterial treat-
ment through parameter H32.
The anti-legionella treatment is controlled through the follow-
ing parameters:
−H07 thermal shock setpoint (increase of water tempera-
ture)
−H08 treatment frequency (monthly, weekly, etc.)
−H09 number of cycles for each treatment
−H10 duration of each cycle (permanence period at the
thermal shock temperature)
−H11 time interval between two consecutive cycles (e.g.
24h).
When the preset time expires (parameter H08) the control
warns, through LED L16 ashing and beeper activation (two au-
dible warnings) that the antibacterial treatment must be per-
formed. By pressing [SET] key, the temperature starts increas-
ing through the heating element (LED L3 steady on) or the boiler
(LED L4 steady on) according to the value of parameter H50. Dur-
ing the treatment LED L16 is steady on, while the cycle count is
displayed.
If you do not want to perform the treatment, simply press [UP]
key: LED L16 turns off and the counter is reset. [UP] key oper-
ates with the machine in Stand by and not during OFF status.
With the unit ON, it is possible to manually force the antibacterial
treatment at any time, through [FUNCTION] key rst and then
[SET] key, for conrmation.