15
INTRODUCTION
4.11
Setting the domestic hot water parameters
Parameter 35 defines the various operation modes of the boiler for
DHW production
Mode 0
(No production of domestic hot water)
In this mode the boiler will work only for the heating circuit (see
section "Setting the heating parameters and outdoor reset")
Mode 1
(DHW production with indirect storage tank and indirect tank sen-
sor)
In this mode, the boiler is activated when the temperature record-
ed by the indirect tank sensor 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 hys-
teresis.
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 degrees
compared to the temperature set for the domestic 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 5.4 °F (3 °C),
when the tank has a set point lowered of 5.4 °F (3 °C), the
boiler turns on at the minimum to allow maintenance
until the set point plus hysteresis. If this parameter is
equal to parameter 36, this function is inactivated and the
boiler 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
parameters:
− Press MENU and select "Domestic Hot Water" using the
▲
/
▼
buttons.
“
Menu
”
“
Central Heating (CH)
”
“
Domestic Hot Water (DHW)
”
“
Information
”
“
Settings
”
− Press the
●
button to confirm.
“
Domestic Hot Water (DHW)
”
“
DHW Setpoint
”
113.0
“
°F
”
− Use the
►
button to highlight the value, and use the
▲
/
▼
buttons to change the selected value. Press the
●
button to
confirm/save the new settings.
The DHW value can be changed only when the "domestic hot wa-
ter" function is enabled. See section "Password access" for instruc-
tions about outdoor recovery.
Mode 2
(DHW production with indirect storage tank controlled by a ther-
mostat)
In this case the boiler is activated when the boiler's thermostat
contact 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 degrees
compared to the temperature set for the domestic 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 indirect
tank sensor is not installed and it influences the supply
temperature of the boiler.
It can be used to limit the difference between the actual supply
and set temperature on the indirect tank sensor so that the system
efficiency is maximized.
Also in this case,the setpoint value can be set directly, without en-
tering the parameters list, by accessing the “Domestic Hot Water”
menu, as mentioned earlier for mode 1.
