GASTER N 67 ÷ 107 AW
10
EN
cod. 3541A180 - 03/2011 (Rev. 00)
3. INSTALLATION
3.1 General Instructions
B
This unit must only be used for its intended purpose.
This unit is designed to heat water to a temperature below boiling point at at-
mospheric pressure and must be connected to a heating system and/or a water
supply system for domestic use, compatible with its performance, characteris-
tics and its heating capacity. Any other use is considered improper.
THE BOILER MUST ONLY BE INSTALLED BY QUALIFIED PERSONNEL, IN AC-
CORDANCE WITH ALL THE INSTRUCTIONS GIVEN IN THIS TECHNICAL MANUAL,
THE PROVISIONS OF CURRENT LAW, ANY LOCAL REGULATIONS AND THE
RULES OF PROPER WORKMANSHIP.
The Manufacturer declines any liability for damage or injury caused by incorrect installa-
tion.
3.2 Place of installation
This unit is an “open chamber” type and can only be installed and operated in perma-
nently ventilated rooms. An insufficient flow of combustion air to the boiler will affect its
normal operation and fume evacuation. Also, the fumes forming in these conditions (ox-
ides) are extremely harmful to the health if dispersed in the domestic environment.
Therefore the place of installation must be free of dust, flammable materials or objects
or corrosive gases. The room must be dry and not subject to freezing.
When positioning the boiler, leave sufficient space around it for normal maintenance ac-
tivities.
3.3 Plumbing connections
Important
The heating capacity of the unit must be previously established by calculating the build-
ing'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 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 its complete emptying.
If the boiler is installed at a lower level than the system, it is advisable to provide a flow-
stop valve to prevent the natural circulation of water in the system.
The temperature drop between the delivery manifold and the return to the boiler should
not exceed 20°C.
B
Do not use the water system pipes to earth electrical appliances.
Before installation, carefully wash all the pipes of the system to remove any residuals or
impurities that could affect proper operation of the unit.
Carry out the relevant connections as indicated in fig. 11.
It is advisable to install shutoff valves between the boiler and heating system, allowing
the boiler to be isolated from the system if necessary.
B
Make the boiler connection in such a way that its internal pipes are free of
stress.
Water system characteristics
In the presence of water harder than 25° Fr, it is advisable to use suitably treated water,
in order to avoid possible scaling in the boiler caused by hard water, or corrosion pro-
duced 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 prob-
lems.
Water treatment is indispensable in case of very large systems (containing large
amounts of water) or with frequent introduction of replenishing water in the system. If par-
tial or total emptying of the system becomes necessary in these cases, it is advisable to
refill with treated water.
Filling boiler and system
The filling pressure with system cold system must be approx. 1 bar. If, during operation,
the system pressure falls (due to the evaporation of gases dissolved in the water) to val-
ues 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.
3.4 Gas connection
B
Before carrying out the connection, make sure the unit is arranged for using the
type of fuel available and carefully clean all the pipes of the gas system to re-
move any residues that could affect proper boiler operation.
The gas must be connected to the relevant connection (see fig. 11) in conformity with
current standards, with a rigid metal pipe or with a continuous surface flexible s/steel
tube, installing a gas cock between the system and boiler. Make sure all the gas connec-
tions are tight.
The capacity of the gas meter must be sufficient for the simultaneous use of all equip-
ment connected to it. The diameter of the gas pipe leaving the boiler does not determine
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.
B
Do not use the gas pipes to earth electrical appliances.
3.5 Electrical connections
Connection to the power supply
The boiler must be connected to a single-phase, 230 Volt-50 Hz electric line.
B
The unit's electrical safety is guaranteed only when it is correctly connected to
an efficient earthing system in conformity with the current safety regulations.
Have the efficiency and suitability of the earthing system checked by profes-
sionally qualified personnel; the Manufacturer declines any liability for damage
caused by failure to earth the system. Also make sure the electrical system is
adequate for the maximum power absorbed by the unit, as specified on the boil-
er dataplate, in particular ensuring that the section of the system's cables is
suitable for the input.
The boiler is prewired and supplied with a connector located inside the control panel, ar-
ranged for connection to an electronic thermostatic controller (see wiring diagrams in
sec. 5.5). It is also equipped with a three-core cable for connection to the electric line.
The connections to the power supply must be made with a permanent connection and
equipped with a double-pole switch with contact gap of at least 3 mm, interposing fuses
of max. 3A between the boiler and line. It is important to respect the polarities (LINE:
brown wire / NEUTRAL: blue wire / EARTH : yellow/green wire) when making the con-
nections to the electric line.
Accessing the electrical terminal block and components inside the control panel
To access the electrical components inside the control panel, follow the sequence in
fig. 2. The layout of the terminals for the various connections is given in the wiring dia-
grams in the technical data section.
fig. 2 - Accessing the terminal block
Key
A
Undo the 2 self-tapping screws securing the boiler cover.
B
Lift by pressing upwards and remove the cover held to the sides of the boiler by
pins.
C
Undo and remove the two screws and the two plates holding the control panel.
D
Turn the control panel forwards.
Any additional sensitive elements of the system's control and safety devices, tempera-
ture probe, pressure switch, thermostat bulb, etc., must be located on the delivery pipe
within 40 cm of the boiler casing rear wall (see fig. 3).
Key
A
System delivery
B
System return
C
40 cm max.
fig. 3 - Delivery and return
3.6 Connection to the flue
The flue connection pipe diameter must not be less than that of the connection on the
anti-backflow device. Starting from the anti-backflow device it must have a vertical sec-
tion at least 50 cm long. Comply with the current regulations regarding installation and
sizes of the flues and connection pipe.
The diameters of the anti-backflow device collars are given in table 1.
A
B
C
