GASTER N 119 ÷ 289 AW
2.3 Plumbing connections
The heating capacity of the unit must be previously established by
calculating the building's heat requirement according to the current
regulations. To ensure proper operation and long boiler life, the
plumbing system must be adequately sized and complete with all
the necessary accessories.
If the system delivery and return pipes follow a path where air
pockets can form in certain places, it is advisable to install vent
valves at these points. Also, install a discharge device at the lowest
point in the system to allow complete emptying.
If the boiler is installed at a lower level than the system, it is advis-
able to install a flow-stop valve to prevent the natural circulation
of water in the system.
The temperature difference between the delivery manifold and the
return to the boiler should not exceed 20°C.
Do not use the water system pipes to earth electrical
appliances.
Before installation, flush all the pipes of the system thoroughly to
remove any residuals or impurities that could affect proper opera-
tion of the unit.
Carry out the relevant connections as indicated in fig. 2.
It is advisable to install shutoff valves between the boiler and
heating system allowing the boiler to be isolated from the system
if necessary.
Make the boiler connection in such a way that its internal
pipes are free of stress.
Water system characteristics
With water harder than 25° Fr, the use of suitably treated water is recommended in order to avoid possible scaling in the boiler, caused
by hard water, or corrosion produced by aggressive water. Due to its low thermal conductivity, scaling even just a few mm thick causes
significant overheating of the boiler walls, with consequent serious problems.
Water treatment is indispensable in the case of very large systems (containing large amounts of water) or with frequent introduction of
replenishing water in the system. If partial or total emptying of the system becomes necessary in these cases, it is advisable to refill with
treated water.
System and boiler filling
The filling pressure with system cold must be approx. 1 bar. If, during operation, the system pressure falls (due to the evaporation of gases
dissolved in the water) to values below the minimum described above, the user must bring it to the initial value. For correct operation of
the boiler when hot, its pressure must be approx. 1.5÷2 bar.
2.4 Gas connection
Before carrying out the connection, make sure the unit is arranged for operation with the type of fuel available and carefully clean
all the pipes of the gas system to remove any residues that could affect proper boiler operation.
The gas must be connected to the relevant connection (see fig. 2) in conformity with the current regulations, with a rigid metal pipe or with
a continuous flexible s/steel tube, installing a gas cock between the system and boiler. Make sure that all the gas connections are tight.
The capacity of the gas meter must be sufficient for the simultaneous use of all units connected to it. The diameter of the gas pipe leaving
the boiler is not decisive for choosing the diameter of the pipe between the unit and the meter; it must be chosen according to its length
and pressure losses, in conformity with the current regulations.
Do not use the gas pipes to earth electrical appliances.
EN
E
a1
a3
D
E
a2
Type and model
GASTER N 119 AW
GASTER N 136 AW
GASTER N 153 AW
GASTER N 170 AW
GASTER N 187 AW
GASTER N 221 AW
GASTER N 255 AW
GASTER N 289 AW
cod. 3541F272 - Rev. 00 - 06/2018
C
A
fig. 2 - Rear view
a1
A
C
D
E
Heating
delivery
930 220
50
42
2"
1020 250
53
45
2"
1100 250
58
43
2"
1190
30
60
46
2"
1270 300
58
44
2"
1440 300
57
45
2"
1610 350
62
46
2"
1780 350
66
49
2"
a2
a3
Heating
Gas
return
inlet
2"
1"
2"
1"
2"
1" 1/2
2"
1" 1/2
2"
1" 1/2
2"
1" 1/2
2"
1" 1/2
2"
1" 1/2
23