89
–With the domestic hot water potentio-
meter knob on maximum, the domestic
hot water tap open and the burner igni-
ted, turn the screw (2) keeping locked
the nut (3) to achieve the minimum pres-
sure value given in
Table 4
: to reduce the
p r e s s u r e , t u r n t h e s c r e w c o u n t e r -
clockwise; to increase the pressure, turn
it clockwise.
– Operate the main switch a number of
times, keeping the D.H.W. tap open all the
time, and check that the pressure corre-
sponds to the values given in
Table 4
.
–Restore electric power to the modulator.
–Replace the plastic cap (1) in position.
4.3.3
Maximum pressure adjustment
valve HONEYWELL
(fig. 28/a)
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. 27/b.
–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
.
4.3.4
Minimum pressure adjustment
valve HONEYWELL
(fig. 28/a)
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).
4.4
ADJUSTMENT OF HEAT
OUTPUT FOR HEATING
To adjust boiler heat output for heating pur-
poses, i.e., modifying the setting made at the
factory which is approximately 16 kW, use a
screwdriver to adjust the heating heat output
trimmer (1 fig. 21). To increase working pres-
sure, turn the trimmer clockwise; to reduce
pressure, turn the trimmer counterclockwise.
To facilitate the operations of adjusting heat
output, see the pressure/heat output dia-
grams for natural gas (methane) and butane
or propane gas (figg. 29 - 29/a - 29/b).
KEY
1
Plastic cap
2
Minimum pressure adjusting screw
3
Maximum pressure adjusting nut
Fig. 28
Fig. 28/a
KEY
1
Plastic cap
2
Minimum pressure adjusting nut
3
Maximum pressure adjusting 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)
25
30
Fig. 29
Pressure/heat output diagram for natural gas (methane)
25
20
15
10
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
30
5
29,0 (25.000)
25
30
Fig. 29/a
Pressure/heat output diagram for butane gas (G30)
HEAT OUTPUT kW (kcal/h)
N
OZZLE
PRESSURE
mbar
HEAT OUTPUT kW (kcal/h)
N
OZZLE
PRESSURE
mbar
