Troubleshooting Service Faults - Baxi NUVOLA DUO-TEC GA Series Instruction Manual For Users And Fitters

15. TROUBLESHOOTING SERVICE FAULTS

The faults shown on the display are identified with the symbol
following table.
If appears on the display the fault must be RESET by the user.
To RESET the boiler, press and hold down
Description of fault
09
Gas valve connection error
10
External probe sensor faulty
12
Hydraulic differential pressure switch switching failure
13
Hydraulic differential pressure switch contacts stuck
15
Gas valve control error
18
Hydraulic circuit automatic filling in progress
19
Fault in system filling phase
20
NTC flow sensor faulty
28
NTC fumes sensor faulty
40
NTC return sensor faulty
NTC domestic hot water sensor faulty
50
(only for heating-only model with storage boiler)
53
Fumes outlet obstructed
55
Electronic board not calibrated
Communication problem between boiler board and control unit.
83...87
Probable short circuit on wiring.
92
Fumes fault during calibration (probable fumes recirculation)
Air in boiler circuit
109
(temporary fault)
Safety thermostat tripped due to overtemperature (pump
110
probably blocked or air in heating circuit).
117
Pressure in hydraulic circuit too high (> 2,7 bar)
118
Pressure in hydraulic circuit too low
No circulation safety trip
125
(control performed via a temperature sensor)
128
No flame
129
Loss of flame at ignition
130
Fumes NTC tripped due to overtemperature
and a number (fault code). For a complete list of faults, see the
for 2 seconds. If faults are displayed frequently, call the Authorised Service Centre.
Service Action
Check the connections between the gas valve and the
electronic board.
Check the sensor (*).
Check correct operation of the pressure switch and the wiring.
See the actions indicated in E12
Check the connections between the gas valve and the
electronic board. If necessary, replace the electronic board.
Wait for the end of the filling cycle.
Check the filling tap.
Check the sensor (**).
Check the continuity of the probe wiring.
Make sure the wiring has not shorted.
Check the fumes NTC probe (***).
Check the continuity of the probe wiring.
Make sure the wiring has not shorted.
See the actions indicated in E20
See the actions indicated in E20
Check that the drainage pipe is free from obstructions. Switch
off the electric power supply to the boiler for a few seconds.
Activate the automatic calibration function described in the
spare parts instructions sheet.
Check the wiring between the Ambient Unit and the electronic
board or RF link.
Check for any recirculation of fumes. Activate the automatic
calibration function described in the paragraph YEARLY
MAINTENANCE – REPLACING COMPONENTS.
Check pump operation (unscrew the front cap and release the
pump impeller with a screwdriver).
Check the pump power input wiring.
Check pump operation (unscrew the front cap and release the
pump impeller with a screwdriver).
Check the pump power input wiring.
Check that the limit thermostat is undamaged and replace it if
necessary.
Check the continuity of the limit thermostat wiring.
Check that the pressure in the system is correct; See the
FILLING THE SYSTEM section.
If the pressure in the CH circuit is < 0.5 bar, perform filling (see
the FILLING THE SYSTEM section).
Check the hydraulic pressure switch works correctly .
See the actions indicated in E109
Check the flame sensing electrode is in good condition
and correctly positioned (see the ANNUAL SERVICING -
POSITIONING THE ELECTRODES section).
Check the wire is uninterrupted and makes good contact with
the flame sensing electrode and the ignition switch.
See the actions indicated in E92
Check the flame sensing electrode is in good condition
and correctly positioned (see the ANNUAL SERVICING -
POSITIONING THE ELECTRODES section).
Check the wire is uninterrupted and makes good contact with
the flame sensing electrode and the ignition switch.
Check for any recirculation of fumes.
Check the heat exchange of the water/ fumes exchanger:
insufficient circulation or presence of scale.
Check the fumes NTC probe (***).
35 7114043.01 (1-06/13)