Immergas 3.028358, Instructions And Recommendations

Page: 35 / 80

35
INS
TALLER
U
SER
M
AINTEN
AN
CE
TECHNI
CI
AN
TECHNI
CAL
D
AT
A
1.29 CIRCULATION PUMP
During central heating mode, the Auto and Fixed operating
modes are available.
-
Auto (A5 = 0):
automatic circulator pump speed and propor-
tional head: the circulator pump speed varies according to the
power supplied by the burner, the greater the power the greater
the speed. Moreover, within the parameter, one can also adjust
the circulator pump operating range by setting the maximum
speed “A3” parameter (adjustable from 6 to 9) and the “A4” min-
imum speed parameter (adjustable from 6 to max set speed).
- ∆T Constant (A5 = 5 ÷ 25 K): the pump speed varies to main-
tain the ∆T constant between the system flow and return ac-
cording to set value K
(A5 = 15 Default).
-
Fixed (6 ÷ 9):
by setting parameters “A3” and “A4” at the same
value, the pump operates at constant speed.
For the boiler to work properly, it is not allowed to drop
below the speed minimum value.
In domestic hot water mode, the circulator pump always
runs at full speed.
Pump release.
If after a long period of inactivity, the circulator is blocked, adjust
the screw in the centre of the head in order to manually release the
motor shaft.
Take great care during this operation to avoid damage to the mo-
tor.
Bypass Adjustment (Parag. 1.32).
The boiler leaves the factory with the bypass open.
If necessary, the by-pass can be regulated to system requirements
from minimum (by-pass closed) to maximum (by-pass open).
Adjust using a flat head screwdriver, turn clockwise and open the
by-pass, anticlockwise it is closed.
The by-pass ensures minimum circulation of the water
in the boiler and correct operation of the appliance if the
systems are divided into more than one zone.
Total head available to the system.
H
ea
d (
kPa
)
v6
v9
v9
A
B
C
D
Ci
rc
ul
at
or
pu
m
p a
bs
or
be
d p
ow
er
(W
)
Flow rate (l/h)
35
Key (Fig. 35):
A+B = Head available with by-pass closed
B = Head available with by-pass open
C+D = Power absorbed by the pump with by-pass closed (dotted area)
D = Power absorbed by the pump with by-pass open (dotted area)
Speed (Fig. 35):
v6 = Speed 6
v9 = Speed 9