Fault finding and diagnosis
Greenstar 4000 – 6 720 891 161 (2020/09)
72
233
V
Boiler identification module or device
electronics faulty
▶ Wrong code plug is inserted.
▶ Check the code plug is not damaged.
▶ Replace the code plug if required.
234
V
Gas valve electrical fault
▶ Check the gas supply to the property and the inlet on the gas valve (check drop on
inlet).
▶ Check the connections on the gas valve and the board (loose connection).
▶ Check the continuity down harness and replace if required.
▶ Check the voltage to the gas valve (19‒24 V DC approx. when demand).
▶ Check for water on the gas valve connections.
▶ Check the resistance on the gas valve (pins 1‒2 approx. 69.5 Ohms).
▶ Replace the gas valve if resistances are incorrect.
▶ If all tests are correct: replace the PCB.
235
V
Conflicting versions of boiler electr. and
boiler identification
▶ Replace the code plug or the burner control.
237
V
System fault
▶ Check the code plug is not damaged.
▶ Replace the code plug if required.
▶ Replace the control unit (PCB).
238
V
Boiler electronics faulty
▶ Check the gas supply to the property and the inlet on the gas valve (check drop on
inlet).
▶ Check the connections on the gas valve and the board (loose connection).
▶ Check the continuity down harness and replace if required.
▶ Check the voltage to the gas valve (19‒24 V DC approx. when demand).
▶ Check for water on the gas valve connections.
▶ Check the resistance on the gas valve (pins 1‒2 approx. 69.5 Ohms).
▶ If all tests are correct: replace the PCB.
242
V
Boiler electr. system fault
▶ Reset appliance electronics (factory reset).
▶ Check the electrical connections on the board (check for loose wires etc.).
▶ Replace the control unit.
245
V
System fault boiler electronics / basic
controller
▶ Reset appliance electronics (factory reset).
▶ Check the electrical connections on the board (check for loose wires etc.).
▶ Replace the control unit.
249
V
System fault boiler electronics / basic
controller
▶ Reset appliance electronics (factory reset).
▶ Check the electrical connections on the board (check for loose wires etc.).
▶ Replace the control unit.
250
V
System fault boiler electronics / basic
controller
▶ Reset appliance electronics (factory reset).
▶ Check the electrical connections on the board (check for loose wires etc.).
▶ Replace the control unit.
251
V
System fault boiler electronics / basic
controller
▶ Reset appliance electronics (factory reset).
▶ Check the electrical connections on the board (check for loose wires etc.).
▶ Replace the control unit.
252
V
System fault boiler electronics / basic
controller
▶ Reset appliance electronics (factory reset).
▶ Check the electrical connections on the board (check for loose wires etc.).
▶ Replace the control unit.
253
V
System fault boiler electronics / basic
controller
▶ Reset appliance electronics (factory reset).
▶ Check the electrical connections on the board (check for loose wires etc.).
▶ Replace the control unit.
254
V
System fault boiler electronics / basic
controller
▶ Reset appliance electronics (factory reset).
▶ Check the electrical connections on the board (check for loose wires etc.).
▶ Replace the control unit.
258
V
System fault boiler electronics / basic
controller
▶ Reset appliance electronics (factory reset).
▶ Check the electrical connections on the board (check for loose wires etc.).
▶ Replace the control unit.
259
V
System fault boiler electronics / basic
controller
▶ Reset appliance electronics (factory reset).
▶ Check the electrical connections on the board (check for loose wires etc.).
▶ Replace the control unit.
Fa
ult
co
de
Fa
ult
ca
te
go
ry Fault text on the display, description
Remedy
