69
COMMISSIONING AND MAINTENANCE
3.1.5
Setting the domestic hot water parameters
The parameter 35 defines the various operation modes of the
thermal module for DHW production
Mode 0
(No production of domestic hot water)
In this mode the thermal module will work only for the heating
circuit (see paragraph "Setting the heating parameters")
Mode 1
(DHW production with storage tank and storage cylinder probe)
In this mode, the thermal module is activated when the tem-
perature recorded by the storage cylinder probe falls below the
DHW setpoint by an amount equal to the hysteresis value and is
deactivated when the temperature rises above the DHW setpoint
by the value of the hysteresis.
The parameters that control DHW production are the following:
Par.
No. Description
36
Defines the hysteresis to initiate the domestic hot
water demand.
37
Defines the hysteresis to stop the domestic hot water
demand.
38
Defines the primary circuit's set-point increase in de-
grees compared to the temperature set for the domes-
tic hot water tank.
39
Defines the primary circuit's restart hysteresis in modes
1 and 2 of DHW (valid both for cascade and stand-
alone applications).
40
Defines the primary circuit's shut-off hysteresis in
modes 1 and 2 of DHW (valid both for cascade and
stand-alone applications).
41
Defines the value referred to the Delta T of the tank for
maintenance purposes. E.g.: if it is set on 3, when the
tank has a set point lowered of 3 degrees, the module
turns on at the minimum to allow maintenance till the
set point plus hysteresis. If this parameter is equal to
36, this function is inactivated and the thermal mod-
ule starts at the maximum sanitary power.
48
Establishes the DHW storage tank set-point.
The setpoint value can be set directly, without entering the list
of the parameters:
− Press MENU and select "Domestic Hot Water" using the
▲
/
▼
keys.
“
Menu
”
“
Central Heating (CH)
”
“
Domestic Hot Water (DHW)
”
“
Information
”
“
Settings
”
− Press the
●
key to confirm.
“
Domestic Hot Water (DHW)
”
“
DHW Setpoint
”
45.0
“
°C
”
− Use the
►
key to highlight the value, and use the
▲
/
▼
keys to change the selected value. Press the
●
key to con-
firm/save the new settings..
the DHW value can be changed only when the "domestic hot
water" function is enabled. See paragraph "Password access"
for instructions about outdoor recovery.
Mode 2
(DHW production with storage tank controlled by a thermostat)
In this case the thermal module is activated when the contact in
boiler's thermostat is closed and is deactivated when the latter
is opened.
The parameters that control DHW production are the following:
Par.
No. Description
38*
Defines the primary circuit's set-point increase in de-
grees compared to the temperature set for the domes-
tic hot water tank.
39
Defines the primary circuit's restart hysteresis in modes
1 and 2 of DHW (valid both for cascade and stand-
alone applications).
40
Defines the primary circuit's shut-off hysteresis in
modes 1 and 2 of DHW (valid both for cascade and
stand-alone applications).
48
Establishes the DHW storage tank set-point.
(*)
Parameter 38 is active on such mode even if the
tank probe is not installed and it influences the flow
temperature of the module.
It can be used to limit the difference between the flow and set
temperature on the tank thermostat so that the system efficien-
cy is maximized.
Also in this case,the setpoint value can be set directly, without
entering the parameters list, by accessing the “Domestic Hot
Water” menu, as already earlier for mode 1.
