GASTER N 67 ÷ 107 AW
11
EN
cod. 3541A180 - 03/2011 (Rev. 00)
4. SERVICE AND MAINTENANCE
4.1 Adjustments
All adjustment and conversion operations must be carried out by Qualified Personnel.
The manufacturer declines any liability for damage or injury caused by unqualified and
unauthorised people tampering with the unit.
Burner gas pressure adjustment
The boilers
GASTER N 67 ÷ 107 AW
are arranged to run on natural or liquefied gas. The
pressure setting and test are performed in the factory.
However, at first lighting, as there may be supply pressure variations, check and if nec-
essary adjust the pressure at the nozzles, respecting the values given in the technical
data table in sec. 5.3.
Pressure adjustment operations must be carried out with the boiler working, using the
pressure regulator on the 2-stage gas valves (see fig. 4)
Preliminary operations:
1.
Light the boiler and turn the control thermostat knob to minimum.
2.
Connect a pressure gauge to the pressure point on the gas manifold pipe of the
burner assembly (see part 14 of fig. 12).
3.
Remove the protection cap of the pressure regulator 4 of fig. 4.
Minimum power (1st stage) adjustment
1.
Turn the control thermostat knob slowly clockwise to the 1st click; the gas valve will
thus be supplied only on connections A and B (see fig. 4).
2.
Turn the screw 6 of fig. 4, checking that the pressure matches the values given in
the technical data table in sec. 5.3.
Maximum power (2nd stage) adjustment
1.
Turn the control thermostat knob to maximum; the gas valve will now be supplied
only on connections A, B and C (see fig. 4).
2.
Turn the screw 5 of fig. 4, checking that the pressure matches the values given in
the technical data table in sec. 5.3.
The adjustment operations must be performed uniformly on the pressure regulators of
all the valves.
B
The gas pressures measured at the burner gas manifold must be read at least
30 seconds after making the adjustments, i.e. when the flame has stabilised.
On completing the adjustment operations, turn the burner on and off 2 - 3 times with the
control thermostat and check that the pressure values are those just set; otherwise, it is
necessary to make another adjustment to bring the pressures to the correct values.
Gas conversion
The unit can work with Natural gas (G20-G25) or liquefied gas (G30-G31) and is factory-
set for use with one of the two gases, as clearly shown on the packing and dataplate.
Whenever the unit has to be used with a different gas, a conversion kit will be required,
proceeding as follows.
From natural to liquefied gas
1.
Replace the nozzles at the main burner and pilot burner, fitting the nozzles specified
in the technical data table in sec. 5.3.
2.
Remove the small cap 3 (fig. 4) from the gas valve, screw the ignition "STEP" regu-
lator 2 (contained in the conversion kit) onto the valve and refit the cap 3 on the reg-
ulator.
3.
Adjust the burner gas pressures for minimum and maximum power as described in
the previous section, setting the values given in the technical data table of section
sec. 5.3.
4.
Operations 2 and 3 must be performed on all the valves.
5.
Apply the sticker contained in the conversion kit, near the dataplate as proof of the
conversion.
From liquefied to natural gas
Carry out the same operations described above, making sure to remove the ignition
"STEP" regulator 2 of fig. 4 of the gas valve; the cap 3 of fig. 4 must be fitted directly on
the valve.
fig. 4 - Gas conversion
Key of main components
1
Pressure point upstream
2
Ignition "STEP" regulator for liquefied gas
3
Plug
4
Protection cap
5
Pressure adjustment screw for max. power
6
Pressure adjustment screw for min. power (1st stage)
7
O-ring
8
Decrease
9
Increase
V
Honeywell valve VR 4601 CB
Key of electrical connections
A + B =
Connections fed for min. power (1st stage)
A + B + C =
Connections fed for max. power (2nd stage)
4.2 Commissioning
B
Commissioning must be carried out by Qualified Personnel.
The following operations and checks must be made at first lighting, and after all mainte-
nance work involving disconnection from the systems or work on safety devices or parts
of the boiler.
Before lighting the boiler
•
Open any shutoff valves between the boiler and the system.
•
Check the tightness of the gas system, proceeding with caution and using soapy wa-
ter to check for any leaks in connections.
•
Fill the water system and make sure all air contained in the boiler and the system
has been vented by opening the air valve on the boiler and any vent valves in the
system.
•
Make sure there are no water leaks in the system or boiler.
•
Make sure the electrical system is properly connected.
•
Make sure the unit is connected to an efficient earthing system.
•
Make sure the pressure and gas flow values are those required for heating.
•
Make sure there are no flammable liquids or materials in the immediate vicinity of
the boiler.
8
9
5
4
6
V
