Unical Osa S 24, Installation And Servicing Manual, Page: 45 / 52

45
Maintenance instructions
ENGLISH
16
Exchanger Freezing ( 24 )
Exchanger freezing is detected If the heating
sensor detects a temperature below 2° C,
burner ignition is inhibited until the sensor
detects a temperature above 5°C
Disconnect the from the power supply, close the
gas valve, defrost the exchanger carefully.
20 Parasite Flame
Flame detected after swtich-off
Check the wiring and for any leaks from the
gas valve (3), if needed replace the gas valve.
24 Speed out of control
Check fan operation (18) and the con -
nections
Check fan operation (18) and the connections
25
Exhaust smoke overheating
26
Speed out of control
Alteration of the fan speed; the speed is
above that requested
Check fan operation (18) and the connections
28 Scambiatore Ostruito
30 Service Parameter
Service parameters altered due to possible
electromagnetic interferences.
Reset and via Ufly restore the altered parameters
31
System configuration invalid or
corrupted
32
Low line voltage Correction: if the line voltage is <190 Vac: the
line voltage is really below the minimum limit,
otherwise the line monitor error: replace BMM
38
Factory Parameters
Alteration of the factory parameters due to
possible electromagnetic interferences.
Press RESET; if the anomaly persists, replace
the board.
44 water sensor pressure
detected if the pressure Transducer is
present
Wait for the values to return to default limits / Re -
place the Transducer
45
water Overheater
detected if the H
2
O pressure Transducer is
present with pressure > 2.5 bar; it is reset
automatically when H
2
O pressure < 2 bar
Wait for the values to return to default limits /
Replace the Transducer
47 Communication error
49
HCM, SHC: host controller missing
50
Room1: temperature sensor
56
Host controller missing
57
Burners NOT detected
58 Global flow temperature sensor
60 Date and Time not valid
62 Actuators SGV
66 Missing calibration
74 Temp. sensors swap
75 Temperature slope exceeds the limit