"Dhw Comfort" Function - Riello Vokera EASI-HEAT i User Instructions

TYPE OF BUILDING (parameter 432)
It is indicative of the frequency with which the value of the cal-
culated outdoor temperature for thermoregulation is updated, a
low value for this value will be used for buildings that have little
insulation.
SENSOR REACTIVITY (parameter 433)
It is an indication of the speed with which variations of the
measured outdoor temperature affect the calculated outdoor
temperature value for thermoregulation, low values indicate high
speeds.
CHOICE OF THE THERMOREGULATION CURVE (para-
meter 419)
The thermoregulation curve for heating maintains a theoreti-
cal temperature of 20°C indoors, when the outdoor tempera-
ture is between +20°C and -20°C. The choice of the curve de-
pends on the minimum outdoor temperature envisaged (and
therefore on the geographical location) and on the delivery
temperature envisaged (and therefore on the type of system).
It is carefully calculated by the installer on the basis of the
following formula:
KT = T. delivery envisaged - Tshift
20- T. min. design external
Tshift = 30°C standard system
25°C floor system
If the calculation produces an intermediate value between two
curves, you are advised to choose the thermoregulation curve
closest to the value obtained.
Example : if the value obtained from the calculation is 1.3, this
is between curve 1 and curve 1.5. Choose the nearest curve,
i.e. 1.5. The settable KT values are as follows:
ƒ standard system: 1,0÷3,0
ƒ floor system: 0,2÷0,8.
Parameter 419 can be used to set the required thermoregu-
lation curve:
THERMOREGULATION CURVES
100
90
T HT
80
70
60
50
T LT
40
30
20
20 15 10
External temperature (°C)
T HT maximum heating setpoint temperature (standard systems)
T LT maximum heating setpoint temperature (free-standing systems)
Offset on the reference ambient temperature
In any case, the user can indirectly modify the HEATING
setpoint value by defining, for the reference temperature
(20°C), an offset that can vary within the range -5 to +5 (offset
0 = 20°C). For the correction of the offset, refer to paragraph
"5.14 Setting the heating setpoint with an external probe".
CLIMATIC CURVE CORRECTION
90
80
70
60
50
40
30
+5°C
20
20°C
-5°C
10
30 25 20 15
External temperature (°C)
NIGHT-TIME COMPENSATION (parameter 420)
If a timer is connected to the AMBIENT THERMOSTAT input,
parameter 420 can be used to enable night-time compensation.
ƒ Set parameter 420 = 1
3,0 2,5 2,0
1,5
1,0
0,8
0,6
0,4
0,2
5 0 -5 -10 -15 -20
10 5 0 -5 -10 -15 -20
In this case, when the CONTACT is CLOSED, the heat re-
quest is made by the flow sensor, on the basis of the outdo-
or temperature, to obtain a nominal ambient temperature on
DAY level (20 °C). The OPENING OF THE CONTACT does
not produce a switch-off, but a reduction (parallel translation)
of the climatic curve on NIGHT level (16 °C).
PARALLEL NIGHT TIME REDUCTION
90
80
70
DAY TEMPERATURE CURVE
60
50
40
30
20
10
20 15 10
External temperature (°C)
In this case too, the user can indirectly modify the HEATING
setpoint value by defining an offset on the reference DAY
temperature (20°C) or the reference NIGHT temperature (16°C)
that can vary within the range [-5 to +5]. NIGHT COMPENSATION
is not available if OT+ chrono is connected. For the correction of the
offset, refer to paragraph "5.13 Setting the heating setpoint".

5.17 "DHW COMFORT" FUNCTION

1
+
>2 sec
2
P H 1
Function Scrolling message
PH0 NO function active
PH1 PRE-HEATING function active
PH1 PRE-HEATING function
Set PH1 to activate the DHW pre-heating function on the
boiler. This function keeps the water in the domestic hot water
exchanger hot, to reduce standby times when a request is
made. The function is not active when the boiler is OFF.
5.18 DHW SPECIAL FUNCTIONS
Parameter 511 is used to activate special functions during the
modulation phase in DHW mode. These functions improve the
boiler performance in particularly hard operating conditions
(such as very high inlet water temperatures, very low flow ra-
tes, use in combination with solar storage tanks).
0 No special function active (default value)
3 Absolute DHW thermostats
4 Smart DHW anti-oscillation function
5 All previous functions active
ABSOLUTE THERMOSTATS function (3)
If this function is activated, the DHW thermostats for burner ON/
OFF switch from the relative value to the absolute one.
ANTI-OSCILLATION function (4)
If this function is activated, the boiler self-configures to ABSO-
LUTE THERMOSTATS if the burner is OFF due to DHW over-
temperature (with a request in progress). When the burner is
OFF, the fan is kept at the minimum speed. The thermostats
go back to being "correlated" at the end of the request.
NIGHT TEMPERATURE CURVE
5 0 -5 -10 -15 -20
P H O
P H 1
25