Control And Operation Devices - Baxi LUNA 3 COMFORT AIR 250 Fi Manual Para El Usuario Y El Instalador

21. control and operation devices

The boiler has been designed in full compliance with European reference standards and in particular is equipped with the following:
• air pressure switch for forced draught model
This switch allows the burner to switch on provided the exhaust flue duct efficiency is perfect.
In the event of one of the following faults:
• the flue terminal is obstructed;
• the venturi is obstructed;
• the fan is blocked;
• the connection between the venturi and the air pressure switch is interrupted;
The boiler will stay on stand-by and the display shows error code 03E (see section 9).
• overheat safety thermostat
Thanks to a sensor placed on the heating flow, this thermostat interrupts the gas flow to the burner in case the water contained in
the primary circuit has overheated. under such conditions the boiler is blocked and relighting will only be possible after the cause of
the anomaly has been removed.
See section 9 to rESET normal operating conditions.
It is forbidden to disenable this safety device
• flame ionization detector
The flame sensing electrode, placed on the right of the burner, guarantees safety of operation in case of gas failure or incomplete
interlighting of the burner. The boiler is blocked after 3 relight attempts.
See section 9 to rESET normal operating conditions.
• hydraulic pressure sensor
This device enables the main burner only to be switched on if the system pressure is over 0.5 bars.
• Pump overrun for central heating circuit
The electronically-controlled supplementary running of the pump lasts 3 minutes (F17 - Section 20), when the boiler is in the central
heating mode, after the burner has switched off due to a room thermostat or intervention.
• Pump overrun for domestic hot water circuit
The electronic control system keeps the pump operating for 30 seconds in domestic hot water mode when the D.H.W. request has
cut off.
• frost protection device
Boilers electronic management includes a "frost protection" function in the central heating system which operates the burner to reach
a heating flow temperature of 30°C when the system heating flow temperature drops below 5 °C.
This function is enabled when the boiler is connected to electrical supply, the gas supply is on and the system pressure is as requi-
red.
• lack of water circulation (probable pump jammed or air in the circuit)
If the water inside the primary circuit doesn't circulate, the display shows 25E error (see section 9).
• anti-block pump function
In the event that no heat is required, the pump will automatically start up and operate for one minute during the following 24 hours.
This function is operative when the boiler is powered.
• three-way anti-blockage valve
In the case of no heat is request for a period of 24 hours the three way valve carries out a complete commutation.
This function is operative when the boiler is powered.
• hydraulic safety valve (heating circuit)
This device is set to 3 bar and is used for the heating circuit.
The safety valve should be connected to a siphoned drain. use as a means of draining the heating circuit is strictly prohibited.
note: domestic hot water is guaranteed even if the NTC sensor is damaged. In this case, the temperature control is carried out by the
boiler flow temperature.
inStructionS Pertaining to the inStaller
65
- GB
926.427.1