4
USE AND MAINTENANCE
4. 1
D.H.W. TEMPERATURE
ADJUSTMENT
The sistem with a potentiometer for adju-
sting the temperature of D.H.W. with a set-
ting range from 30° to 60°C offers a dou-
ble advantage:
1) The boiler adapts perfectly to any type of
D.H.W. system, whether the mixing
system is a mechanical or a thermostat-
controlled type.
2) The thermal output is dosed according
to the temperature required, which
means a considerable saving in fuel.
NOTE: In order to avoid any misunderstan-
ding please remember that the value obtai-
ned by the product of temperature diffe-
rence (in °C) between D.H.W. output and
input into the boiler by the hourly flow rate
measured on the tap, where hot water is
drawn off (l/h), cannot be higher than the
useful output developed by the boiler.
For measurements and checks on flow
rate and temperature of D.H.W., use sui-
table instruments, taking into considera-
tion any heat dispersion along the stretch
of piping between the boiler and the mea-
suring point.
4.2
ADJUSTMENT OF
D.H.W. FLOW RATE
To adjust the D.H.W. flow rate, use the flow
rate adjuster (5 fig. 5).
Remember that the flow rates and corre-
sponding temperatures of use of hot water,
given in section 1.3, have been obtained by
positioning the selector of the circulation
pump on the maximum value.
Should there be any reduction in the
D.H.W. flow rate, the filter installed on the
inlet to the divertor valve (3 fig. 5) will
need cleaning.
4.3
ADJUSTMENT OF HEAT OUTPUT
FOR C.H. MODE
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 C.H. heat output
trimmer (1 fig. 15).
To increase working pressure, turn the trim-
mer 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 buta-
ne or propane gas (figg. 19 - 19/a - 19/b).
4.3. 1
Measuring gas pressure at nozzles
To measure pressure at the nozzle, con-
nect a manometer to the intake down-
stream of the gas valve.
In "25 BF" models, connect the manome-
Pressure/heat output diagram for natural gas (methane)
14
13
12
11
10
9
8
7
6
5
4
3
2
1
8, 1 (7.000) 11,6 (10.000)
17,4 (15.000)
Pressure/heat output diagram for butane gas (G30)
30
25
20
15
10
5
8, 1 (7.000) 11,6 (10.000)
17,4 (15.000)
Pressure/heat output diagram for propane gas (G31)
35
30
25
20
15
10
5
8, 1 (7.000) 11,6 (10.000)
17,4 (15.000)
35
30
25
23,2 (20.000)
29,0 (25.000)
HEAT OUTPUT kW (kcal/h)
POTENZA TERMICA kW (kcal/h)
25
30
35
23,2 (20.000)
29,0 (25.000)
HEAT OUTPUT kW (kcal/h)
POTENZA TERMICA kW (kcal/h)
25
30
35
23,2 (20.000)
29,0 (25.000)
HEAT OUTPUT kW (kcal/h)
POTENZA TERMICA kW (kcal/h)
IT
ES
PT
GB
GR
RO
RUS
Fig. 19
Fig. 19/a
Fig. 19/b
81