Ferroli PREXTHERM N Serie Instrucciones De Uso página 8

3.4 Maintenance
To ensure the maximum reliability of the heating system and minimum running costs, the boiler must be cleaned regularly, at least once a year.
These maintenance operations must be performed by qualifi ed and specialist personnel.
In any case, it is good practice to check the condition inside the boiler once a week, by opening the front door, so as to avoid anomalous ope-
ration for extended periods. During this operation, all the turbulators should be removed longitudinally, so as to prevent them from becoming
clogged due to the inevitable deposits of soot.
Cleaning the boiler
1 Disconnect the power supply to the boiler
3 Open the door by undoing the 2 nuts (see 2.6).
4 Carefully clean the tube bundle: open the front door of the boiler completely, and remove all the turbulators from the tubes. Thoroughly
clean the tube bundle using the brush. Remove the soot deposits from the rear smokebox, through the door. Brush and scrape the furnace
to remove the deposits of sulphur and other solid substances. Check the nozzles and the position of the burner combustion head, in the
event where carbon deposits are formed (to clean the burner, always refer to the instructions provided by the manufacturer).
5 Close the door again, and fasten it using the knob.
Descaling the boiler
It is extremely important, above all in areas where the water is very hard, to periodically de-scale, or better still, to inhibit the formation of
lime-scale deposits in the system. These periodical or continuous operations are indispensable for extending the life of the boiler and pre-
venting localised overheating of the metal plate, differential expansion or thermal shock. Therefore, after the fi rst operating season at the
latest, thorough descaling should be performed This operation must be repeated at the end of the heating period. If continuous descaling is
practiced, it is essential to use a safe and absolutely non-corrosive product. In addition, it is essential to periodically remove the slime that
deposits inside the boiler, through the special fi tting.
4. TECHNICAL SPECIFICATIONS
Model Ø
mm
Prextherm N 107 400
Prextherm N 145 400
Prextherm N 180 400
Prextherm N 240 450
Prextherm N 300 450
8
Heat input
gas+oil (NHV)
kW
Model
Max
Prextherm N 107 116
Prextherm N 145 158
Prextherm N 180 196
Prextherm N 240 251
Prextherm N 300 326
Combustion chamber
Combustion
chamber
load loss
Lenght Volume A
∆p mbar
mm m3 mm
804 0,10 0,38 760
944 0,12 0,90 760
1144 0,14 1,60 760
1214 0,19 1,85 850
1304 0,21 2,09 850
Heat
Water
output
content
kW
Min Max Min dm3
75 107 70 112
102 145 95 131
140 180 130 156
172 240 150 272
210 300 196 239
Dimensions
B C D E F
mm mm mm mm mm
420 482 873 860 1000
420 482 1023 1010 1000
420 482 1223 1210 1000
465 525 1323 1310 1100
465 525 1423 1410 1100
PREXTHERM N
Water
Operating
pressure drop
pressure
∆t 10°C ∆t 20°C
∆p mbar ∆p mbar
bar
6 2,5 1
6 3,5 1,5
6 4,5 2
6 6,5 3
6 8,0 4
Connections
G H Ø1 Ø2 Ø3
mm mm mm mm mm
80 900 DN50 DN50 180
80 900 DN50 DN50 180
80 900 DN50 DN50 180
90 1000 DN65 DN65 250
90 1000 DN65 DN65 250
Ø4
Ø5
Ø6
Boiler weight
with no load
kg
340
360
400
430
450
Ø4 Ø5 Ø6
1" 3/8" 1"
1" 3/8" 1"
1" 3/8" 1"
1" 3/8" 1"
1" 3/8" 1"
fi g. 5