Adjustment And Safety Devices - Westen Boyler digit 240/40 Fi Manual Del Usuario

22. ADJUSTMENT AND SAFETY DEVICES

This boiler has been designed in full compliance with European reference standards and, in particular, it is fitted with the following:
• Air pressure switch for forced-flow models (240/40 Fi - 240/60 Fi and 280/60 Fi)
This device only allows the main burner to ignite if the exhaust flue duct is in perfect working order.
In the event of one or more of the following faults:
• flue terminal obstructed
• venturi tubes obstructed
• fan blocked
• venturi tube connection - pressure switch tripped
The boiler remains on standby and error code E03 is displayed (see table in section 9).
• Fumes thermostat for natural draught models (240/40 i - 240/60 i and 280/60 i)
This device, the sensor of which is positioned to the left of the fumes hood, interrupts the flow of gas to the main burner if the flue is obstructed and/or
there is no draught.
In these conditions, the boiler is blocked and only after the fault has been eliminated can it be ignited again (section 9).
• Safety thermostat
Thanks to a sensor placed on the heating delivery line, the thermostat interrupts the flow of gas to the burner if the water in the primary circuit ove-
rheats. In these conditions, the boiler is blocked and only after the fault has been eliminated can it be ignited again (section 9).
It is forbidden to disable this safety device
• Flame ionisation detector
The flame sensing electrode guarantees safety of operation in case of gas failure or incomplete ignition of the main burner.
In these conditions, the boiler blocks. To reset normal operations, see section 9.
• Hydraulic differential pressure switch
This device, mounted on the hydraulic unit, only allows the main burner to light if the pump is able to deliver the necessary head. It protects the
water-fumes exchanger if there is no water or if the pump blocks.
• Pump post-circulation
The electronically-controlled pump post-circulation function lasts 3 minutes and is enabled, in the heating mode, if the ambient thermostat causes
the main burner to go out.
• Frost protection device
The electronic boiler management system includes a "frost protection" function for the heating system which, when delivery temperature falls below
5°C, operates the burner until a delivery temperature of 30°C is reached. This function is enabled when the boiler is switched on, the gas supply is
open and the system is correctly pressurised.
• Anti-legionellosis function
The anti-legionellosis function is NOT enabled.
To enable this function, set parameter F21=01 (as described in section 21). When the function is enabled, the electronic management of the boiler,
at weekly intervals, heats the water contained in the storage boiler to over 60°C (the function only works if the water has never exceeded 60°C in the
previous 7 days).
• Anti-block pump function
If no heat demand is received in the heating and/or DHW modes for 24 consecutive hours, the pump will automatically start and operate for 10
seconds. This function is operative when the boiler is powered.
• Three-way valve anti-blockage function
If no heat demand is received for a period of 24 hours, the three-way valve performs a complete switching cycle. 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.
• Hydraulic safety valve (DHW circuit)
This device is set to 8 bar and is used for the DHW circuit (storage boiler).
Connect the safety valves to a drain trap. Do not use it to drain the heating and/or DHW circuit.
INSTRUCTIONS FOR FITTERS
49
926.008.2 - EN