3
Failures / Errors
GB012 - 25K
8
3.2
Failure / Error Codes Overview
Failure
Code on
Display
Failure Descripton
Steps
MAP not selected (Fan speed adjustment
according the flue pipe length).
Check the adjustment /selection via service func-
tion 2.b.d).
1H
Combustion chamber NTC failure (behind
burner) : - when the temperature by CC NTC
reached to limit or
- when NTC not detected or open circuit
Check the and the heat exchanger surface,
whether is blocked or not. And check the sensor
and the connections.
2P
Gradient limit : Temperature rises too rapidly
in heating mode.
Check the pump, system pressure and by-pass
circuit.
3A
Fan sensor not detected.
Check the fan.
3C
Fan speed can not reached to target speed.
Check the fan for the blockage and the electrical
supply.
4C
Overheat lock-out by temperatur limiters
(STBs) (Flue gas + prim. Heatexchanger). In
this case ; Heat demands is blocked and
pump stops 3 min. later.
Check the system presseure, temperature sensor,
pump and fuses on board. Discharge the air in
system. Check also the flue gas pipe and heatex-
changer.
4Y
Flow temperature sensor failure (pump is run-
ning).
Check the flow temperature sensor and the con-
nection.
6A
Ignition lock-out (flame not detected) (pump is
running).
Check the gas cock, gas pressure, electrode and
the cable connection.
6C
Safety valve leaks.
Check the gas valve, the cable connection and
electrode set.
B3
Short circuit / failure in water level switch.
Check the condensate water drain and recuperator
(condens-heatexchanger).
CL
Domestic hot water temperature sensor not
correct installed or failure.
Check the sensor and cable connection.
d7
Modulator coil failure (regulator valve on gas
valve)
Check the cable connection.
Tab. 4
Failure codes
