Worcester Bosch Greenstar 4000 System fault codes

53 codes from the Worcester Bosch manual for the Greenstar 4000 System gas boiler. Pick one for what it means, the likely causes and where to start.

Code	What it means
1010	No communication via EMS BUS connection
1013	Max. combustion point reached
1021	Cylinder charging or hot water temperature sensor faulty
1022	Cylinder temp. sensor faulty or contact problems
1037	Outside temp. sensor faulty - heating backup operation active
1065	System pressure sensor faulty or not connected
1068	Outside temp. sensor or lambda probe faulty
1073	Short-circuit at flow temp. sensor
1074	No signal from flow temperature sensor
1075	Heat exchanger temp sensor short circuit
1076	Heat exchanger temp sensor disconnected
208	Post-purge/pump run-on after chimney sweep mode exit
2085	Internal fault
224	Maximal flue gas thermostat or heat exchanger maximal thermostat has activated
228	Flame signal without flame present
233	Boiler identification module or device electronics faulty
234	Gas valve electrical fault
235	Conflicting versions of boiler electr. and boiler identification
237	System fault
238	Boiler electronics faulty
269	Flame monitoring
281	Operation of burner and fan interrupted
283	Burner starting
284	Opening air/gas ratio control valve/oil solenoid valves
2910	Fault in flue system
2915	Boiler electr. system fault
2916	Boiler electr. system fault
2923	Boiler electr. system fault
2927	Boiler electr. system fault
2928	Internal fault
2931	System fault boiler electronics / basic controller
2940	System fault burner control unit
2948	No flame signal with low output
2949	No flame signal with high output
2950	No flame signal following starting procedure
2951	Loss of flame too many times
2957	Boiler electr. system fault
2961	No fan signal available
2962	No fan signal available
2963	The heat exchanger sensor or both supply and heat exchanger sensors are defect
2964	Flow rate in heat exchanger too low
2965	Flow temperature too high
2966	Flow temperature rise in heat exchanger too rapid
2967	The temperature difference between supply temperature sensor and temperature sensor at...
2970	Pressure drop in heating system too rapid
2972	Mains voltage too low
306	Flame signal after closing the fuel supply
3071	Comfort + II RF communication fault
358	Anti-seizing function active
360	System fault boiler electronics / basic controller
363	System fault boiler electronics / basic controller
810	Hot water remains cold
811	Hot water heating: thermal disinfection failed