Fault finding and diagnosis
81
Greenstar 2000 – 6 721 820 552 (2021/02)
2927 B
Flame failed during burner operation
▶ Check the gas supply to the property and the inlet on the gas valve (check drop on inlet)
and replace if required.
▶ Check the flame sense probe and the earth to the heat exchanger.
▶ Check the voltage to the gas valve and the continuity of harness and replace if required.
▶ Check the condition of the bearing plate.
▶ Check the flame sense plug is connected and the continuity of harness and replace if
required.
▶ Check the fan pressure.
▶ Check the siphon trap and the discharge route.
▶ Check the flue integrity test.
2928 –
Internal error
▶ Restart the appliance to see if the problem re-occurs.
▶ If the fault remains after resetting: the burner controller (PCB) is defective.
2930 V
System fault boiler electronics / basic
controller
▶ If the fault persists following a reset, the burner control unit is faulty and must be
replaced.
2931 –
Illegal instruction executed by
microcontroller
▶ Restart the appliance to see if the problem re-occurs.
▶ If the fault remains after resetting: the burner controller (PCB) is defective.
2932 –
System fault boiler electronics / basic
controller
▶ Perform factory reset.
▶ If problem persists, replace PCB
2940 V
Low voltage
▶ Restart the appliance to see if the problem re-occurs.
▶ If the fault remains after resetting: the burner controller (PCB) is defective.
2941 B
Insuff. flow rate in boiler
▶ Check plug of flow temperature sensor, connect correctly if required.
▶ Check flow temperature sensor, replace if necessary.
▶ Check pump for blockage, clear if required.
▶ Check pump settings, correct if required.
▶ Check water pressure, if necessary top up until the pre-set pressure is reached.
2942 –
No speed feedback signal from fan
▶ Connect plug for speed control to the fan.
▶ Connect plug for power supply to the fan.
▶ Check fan harness.
▶ Check and replace control unit.
2943 –
Mains voltage too low
▶ Establish supply voltage of at least 196 VAC.
2945 V
Too many short heat demands in short time
period
▶ Reset appliance - factory reset.
▶ Increase restart blocking time.
▶ Make sure that at least one thermostatic valve is open.
▶ Check and replace faulty heating pump.
▶ Check diverter valve functionality, replace if necessary.
2946 V
Incorrect code plug detected
If code plug is present:
▶ Check that correct plug is inserted.
▶ Check the code plug is not damaged.
▶ Check code plug against the part number.
▶ Replace the code plug if required.
If code plug is not present:
▶ Check appliance electronics (PCB), replace if necessary.
2947 R
Incorrect code plug detected
The function stops automatically.
2948 B
No flame signal with low output
The burner starts automatically after purging. It may cause strong winds.
▶ If the fault occurs repeatedly: check the settings of the CO
2
values.
▶ Check the flue integrity.
▶ Check the flue terminal.
2949 B
No flame signal with high output
It may cause strong winds or flue gas recirculation. The burner starts automatically after
purging.
▶ Check the flue integrity.
▶ Check the flue terminal position.
▶ Check the CO
2
settings and adjust.
▶ Check the burner and the heat exchanger gaskets and the inner flue gaskets.
▶ Check the gas pressure during burning at full load (working pressure, dropping low).
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