–Disconnect the electric supply of the
modulator.
–With the D.H.W. potentiometer knob on
the maximum value, the hot water cock
open and the burner alight, holding the
nut (3) blocked, turn the screw (2) to find
the minimum pressure value as shown in
Table 4
: to decrease the pressure turn
the nut anti-clockwise and to increase
the pressure turn the nut clockwise.
–Turn on and turn off the burner a few
times whilst keeping the hot water cock
constantly open and verify that the pres-
sure corresponds to the values fixed.
–Reconnect the electrical supply of the
modulator.
–Replace the plastic cap (1)
4.2.2
Maximum and minimum
pressure adjustment
HONEYWELL VK 4105M
(fig. 30)
To set the maximum pressure, proceed as
follows :
– Connect the pressure column to the pres-
sure inlet downstream of the gas valve.
–For the
“BF”
models connect the pressu-
re column as shown in fig. 28.
–Remove the plastic cap on the modula-
tor (1).
–Set the knob of the D.H.W. potentiome-
ter to the maximum value.
–Ignite the boiler and open the D.H.W. cock.
–Using a ø 9 spanner, turn the nut (3) to
achieve the maximum pressure value
given in
Table 4
: to reduce the pressure,
turn the nut counterclockwise; to increa-
se the pressure, turn it clockwise.
– Operate the main switch a number of
times, keeping the D.H.W. cock open all the
time, and check that the pressure corre-
sponds to the values given in
Table 4
.
After adjusting maximum pressure, pro-
ceed to calibrate minimum pressure:
– Disconnect the electric power supply
from the modulator.
– With the hot wat er pot entiomet er
knob set t o t he maximum, t he ho t
water tap turned on and the burner lit,
hold nut (3) locked in place and simulta-
neously turn nut (2) using a fixed ø 7
wrench to identify the minimum pres-
sure value shown in
Table 4
: turn the
nut anti-clockwise to reduce pressure
or clockwise to increase it.
–Turn the boiler on and of f repeatedly
while keeping the hot water tap turned
on, checking that pressure corresponds
to the values shown in
Table 4.
–Connect up the power supply to the
modulator again.
–Replace the plastic cap (1).
4.3
ADJUSTMENT OF
HEATING OUTPUT
To regulate the heating output, modifying
the factory settings whose power value is
around 16 kW, it is necessary to work with
a screwdriver on the trimmer of the heating
power (1 fig. 22).
To increase the operating pressure turn the
trimmer in a clockwise direction, to decrea-
se the pressure turn the trimmer in an anti-
clockwise direction. To facilitate the search
for the adjusting of the heating power the
diagrams pressure/ heat output for natu-
ral gas (methane) and butane or propane
gas are available (fig. 31).
4.4
CONVERSION TO ANOTHER GAS
For the functioning with butane (G30) or
propane (G31) gas, a kit with that needed
for the conversion is supplied.
To convert from one gas to another carry
out the following operations (fig. 32):
88
3
2
1
Fig. 29
KEY
1
Plastic cap
2 Minimum pressure
adjusting screws
3 Maximum pressure
adjusting nut
Fig. 30
KEY
1
Plastic lid
2 Minimum pressure
regulating nut
3 Maximum pressure
regulating nut
11
10
9
8
7
6
5
4
3
2
1
8,1 (7.000) 11,6 (10.000)
17,4 (15.000)
23,2 (20.000)
POTENZA TERMICA kW (kcal/h)
PRESSIONE UGELL
O mbar
29,0 (25.000)
12
25
30
Fig. 31/a
Pressure/heat output diagram for natural gas (methane)
HEAT OUTPUT kW (kcal/h)
N
OZZLE
PRESSURE
mbar
