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M a i n t e n a n c e . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
T e c h n i c a l T r a i n i n g
Fault diagnosis help:
Description
Fault
code Cause
Solution
Heating temperature sensor fault
(NTC2,NTC5)
F00
Flow sensor (NTC2) disconnected
• Check the sensor connections.
• Check the sensor cables
• check the sensor (characteristics
in this chapter at “Measurements”)
F01
Return sensor (NTC5) disconnected
F10
Flow sensor short-circuit (NTC2)
F11
Return sensor short-circuit (NTC5)
Storage tank temperature sensor
fault (NTC1)
F13
Sensor short-circuit : a shunt as been
connected instead of a sensor on X16
Overheating fault
(97°C measured by
the Heating flow sensor)
(NTC2,NTC5)
F20
No water flow
• Check that the pump is working correctly.
• Un-stick the pump.
• Check that the heating taps are open.
• Check the condition of the plate exchanger
if the fault appears in hot water mode.
• Check the condition o the heating filter.
• Bleed the primary circuit.
No water in the installation
(< 0.3 bar) (Cp)
F22
Leak in the installation
Leak in the Pressure relief valve
Expansion tank defective
• Refill and bleed the installation
• Check the expansion tank.
• Check that there are no leaks.
Maximum difference in
temperature between heating
output and return reached (35K).
(NTC2,NTC5)
F23
Water circulation problem
• Check the connections of the heater output
and return sensors.
• Check the pump speed.
• See also solution for fault F20.
Water circulation fault
(temperature rise greater than
10 K/s). (NTC2,NTC5)
F24
Bad pump operation or low water
• See fault 20 or:
• Heating taps closed.
• Pump disconnected or stuck.
Smoke overflow (only for open
flue versions) (K11)
F25
The safety device (K11) on the draught
diverter has detected a smoke overflow.
• Check the exhaust (connection, lenght,
diameter, no blocking,...)
• Check the air intakes on the building
• Check the termostat
note : no electric hood allowed on the same
room than the boiler.
Gas valve stepper motor current
incorrect
F26
Stepper motor disconnected or defective
• Check the stepper motor connection
• Check the motor
Wrong flame detection.
F27
Flame detection in spite of switched off
gas valve.
• Check the flame detection electrode
• Check the main circuit board.
• Check the igniter.
Ignition failure
F28
No or insufficient gas.
Bad gas valve setting.
Gas valve defective
Igniter defective.
Bad earth connection.
ignition and flame control electrode
defective.
• Check the gas supply circuit (gas tap open).
• Check the gas valve.
• Check the adjustment of the gas valve.
• Check the igniter connection.
• Check the electrode condition (corrosion).
Flame failure during burner operation
(FL)
F29
Air pressure switch failure (Pr)
F33
Pressure switch doesn’t switch OFF
when fan is OFF.
• Check the air pressure switch
Coding resistor fault
F42
The coding resistor is not at the
expected value
• Check the coding resistor (R1) on the wiring
N.B: fault 42 can appear alternately with fault 70 if an erroneous product code has been entered in the installer menu.
EBUS voltage error
F49
EBUS line fault
Short circuit in EBUS connector
• Check the EBUS line voltage