5
Externa 30 O
Cod. 3540T540 - 04/2009 (Rev. 00)
1.3 Ignition and shut-down
Ignition
• Open the gas cock upstream of the boiler.
• Close or insert any switches or power plugs upstream of the boiler
• Place the main switch “A” in the ON position.
• Place knob “B” in the Winter position and set the room thermostat, if fitted, to the required tem-
perature value. At this point, the burner will ignite and the boiler will start operating automatically,
managed by its control and safety devices.
If, after having correctly performed the ignition operations, the burners do not ignite and the
shut-down warning light is on, wait around 15 seconds, then turn knob A to the RESET position
and release it. The control unit will be reset and will repeat the ignition cycle. If, after a number
of attempts, the burners do not ignite, refer to the paragraph on troubleshooting.
Shut-down
Close the gas cock upstream of the boiler, turn knob “A” to OFF and disconnect the appliance from
the mains power supply.
When the boiler is off the boiler anti-freeze protection is not active.
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.
1.4 Settings
Summer/Winter setting and system temperature control
With knob
“B”
Fig. 1 in the position of the symbol
(Summer), the central heating function is deac-
tivated.
Only the production of domestic hot water is activated (with the optional external hot water cylinder
installed).
With the knob
“B”
Fig. 1 in the position of the symbol
(Winter), both the central heating function
and domestic hot water are active.
Turning the knob clockwise increases the central heating water temperature, anticlockwise decreases
it. The temperature can be set from a minimum of 35° to a maximum of 85°. It is not recommended,
however, to operate the boiler below 45°.
Setting the ambient temperature (using the optional room thermostat)
Set, using the room thermostat or remote control, the temperature required inside the rooms. Based
on the command from the room thermostat, the boiler is ignited and heats the system water to the set
central heating outlet temperature. When the required temperature inside the rooms is reached, the
boiler switches off.
If no room thermostat or remote control is available, the boiler will maintain the system at the set central
heating outlet temperature.
Domestic hot water temperature control
Set the storage temperature, using knob “D” (supplied in the optional kit).
