Fault finding and diagnosis
75
Greenstar 4000 – 6 720 891 162 (2020/09)
1065 W
System pressure sensor faulty or not
connected
▶ Check the plug is connected correctly to the pressure sensor.
▶ Check pressure sensor connecting leads for breaks or short circuits, replace if
necessary.
▶ Check the pressure sensor, replace if necessary.
1068 W
Outside temp. sensor or lambda probe
faulty.
▶ Check the plug to the temperature sensor, connect correctly.
▶ Check connecting lead for break or short circuit, replace if required.
▶ Check temperature sensor, replace if necessary.
▶ Check appliance electronics, replace control unit if necessary.
1070 W
Maintenance is due on <dd.mm.yyyy>
please call your service engineer
Advanced service reminder warning.
▶ Check the maintenance menu.
▶ Reset the maintenance code via the reset menu.
1071 W
Maintenance is now due please call your
service engineer
▶ Check the maintenance menu.
▶ Reset the maintenance code via the reset menu.
1072 W
Maintenance is overdue please call your
service engineer
▶ Check the maintenance menu.
▶ Reset the maintenance code via the reset menu.
1073 W
Short-circuit at flow temp. sensor
▶ Check the flow temperature sensor plug is connected.
▶ Check the resistance of the flow temperature sensor and replace if required.
▶ Check the continuity of harness and replace if required.
▶ Replace the flow temperature sensor.
1074 W
No signal from flow temperature sensor
▶ Check the flow temperature sensor plug is connected.
▶ Check the resistance of the flow temperature sensor and replace if required.
▶ Check the continuity of harness and replace if required.
▶ Replace the flow temperature sensor.
▶ Replace the PCB.
1075 W
Heat exchanger temp sensor short circuit
▶ Check the flow temperature sensor plug is connected.
▶ Check the resistance of the flow temperature sensor and replace if required.
▶ Check the continuity of harness and replace if required.
▶ Replace the flow temperature sensor.
▶ Replace the PCB.
1076 W
Heat exchanger temp sensor disconnected ▶ Check the flow temperature sensor plug is connected.
▶ Check the resistance of the flow temperature sensor and replace if required.
▶ Check the continuity of harness and replace if required.
▶ Replace the flow temperature sensor.
▶ Replace the PCB.
2085 V
Internal fault
▶ Reset the appliance.
▶ Switch off the appliance for 30 seconds and then turn back on.
▶ Check the incoming mains voltage.
▶ Check the polarity.
▶ Replace the PCB.
2908 V
System fault boiler electronics / basic
controller
▶ Restart the appliance to see if the problem re-occurs.
▶ If the fault remains after resetting: the burner controller (PCB) is defective and must
be replaced.
2910 V
Fault in flue system
▶ Check the flue for obstructions and remove any found.
▶ Check the flue integrity test.
▶ Check for water in the sump and check the siphon operation, clean if required.
2914
–
Boiler electr. system fault
▶ Restart the appliance to see if the problem re-occurs.
▶ If the fault remains after resetting: the burner controller (PCB) is defective and must
be replaced.
2915 V
Boiler electr. system fault
The fan keeps running after the post purge.
▶ Reset the appliance.
▶ Create a heat demand to test the boiler's ignition sequence.
▶ Check the voltage to the fan and the continuity of the fan harness.
▶ Check the power modulation on the fan.
▶ PCB may be defective.
Fa
ult
co
de
Fa
ult
ca
te
go
ry Fault text on the display, description
Remedy
