15
Externa 30 O
Cod. 3540T540 - 04/2009 (Rev. 00)
In the case of power failures while the boiler is in operation, the burners will switch off. When
mains power returns, the burners will automatically re-ignite.
Checks during operation
• Check the fuel circuit and the water system for tightness.
• Check the efficiency of the flues and air-flue gas pipes during the operation of the boiler.
• Check that the water circulation between the boiler and the systems is correct.
• Ensure that the gas valve modulates correctly both in the central heating phase and the production
of domestic hot water.
• Check the correct ignition of the boiler, by performing a series of ignition and shut-down tests using
the room thermostat or the remote control.
• Ensure that the consumption of fuel indicated by the counter corresponds to the values shown in the
technical data table in Chap. 4.
• Check that there is the correct flow rate of domestic hot water with the
¨
t declared in the table: do
not rely on measurements effected using empirical systems. The measurements should be made using
special instruments at a point as close as possible to the boiler, considering the dispersion of heat
from the piping.
• Ensure that without the request for heating the burner ignites correctly when opening a hot water
tap. Check that during operation in central heating mode, when opening a hot water tap, the heating
pump switches off, the domestic hot water pump starts and there is regular production of domestic
hot water.
Shut-down
Close the gas cock upstream of the boiler and disconnect the appliance from the mains power supply.
For extended periods of inactivity during the winter months, in order to avoid damage due to
freezing, all the water should be drained from the boiler, both the domestic hot water and the
central heating system; alternatively, drain only the domestic hot water and place the special
antifreeze fluid in the central heating system.
3.3 Maintenance
The following operations must only be performed by Qualified Personnel, such as personnel from
our sales organisation or local Customer Service Centre.
Seasonal checks on the boiler and the stack
The following checks should be made on the appliance at least once a year:
• The control and safety devices (gas valve, flow-meter, thermostats, etc.) must be working properly.
• The pipes and the air-flue gas terminals must be free of obstacles and not have any leaks.
• The gas and water systems must be perfectly tight.
• The burner and the heat exchanger must be clean. Follow the instructions in the next paragraph.
• The electrodes must be free of deposits and positioned correctly.
• The pressure of the water in the system when cold must be around 1 bar; if not, restore this value.
• The expansion vessel must be full.
• The gas rate and the pressure must correspond to the values indicated in the corresponding tables.
• The circulation pumps must not be blocked.
