Worcester Bosch Greenstar 8000 Boiler Error Codes

Worcester Bosch Greenstar 8000 Boiler Error Codes

Fault DescriptionSystem Behaviour
200 OBoiler in heating mode
201 OBoiler in hot water mode
202 OBoiler in anti-cycle mode
203 0Boiler in standby – no heat energy demand
204 OCurrent primary water temperature higher than set value
208 0Chimney sweep demand
224 VSafety temperature limiter has tripped – top-up water until the reset pressure is reached
227 VNo flame signal after ignition burner control unit could need replacing
228 VFlame signal without flame present – air/gas ratio control valve may need replacing as might the ionisation cable
305 0Boiler in hot water anti-cycle mode
306 VFlame signal after closing the fuel supply – the air/gas ratio control valve might need replacing
360 VIncompatible code plug – check if a correct code plug is installed and exchange or reconnect code plug
815 W/BLow loss header temperature sensor faulty – check the sensor port or check the differential sensor for incorrect installation position or breakage
1010 ONo BUS communication cable, EMS-Bus isn’t connected or damaged – connect the cable for the EMS-Bus or replace the damaged cable exchange fuse
1017 WWater pressure too low – the water needs topping up and the vent system or pressure sensor may need replacing
1021 BHot water temperature sensor is defective – the plug to the hot water temperature sensor may not be connected
1022 BHot water storage temperature sensor is defective – connect the plug to the hot water temperature sensor correctly, mount the hot water temperature sensor correctly or replace the hot water temperature sensor
1037 WOutside temperature sensor is defective – check the connecting lead
1065 BPressure sensor defective or not connected – check pressure sensor connection as it may need replacing
1068 WOutside temperature sensor defective – check the connecting lead
1073 WShort circuit of the flow temperature sensor – the temperature sensor may need replacing
1074 WNo signal from the flow temperature sensor available – connect the plug to the flow temperature sensor correctly or temperature sensor could need replacing
1075 WShort circuit of the temperature sensor at the heating block – temperature sensor may need replacing
1076 WNo signal from the temperature sensor at the heating block available – replace the temperature sensor, the connecting lead or the control unit
2920 VError with the flame monitoring
2924 VNo feedback from the modulating gas valve. The gas valve relay is defective – press the reset button and apply burner start, wait to see if fault reoccurs, if it does the gas valve needs replacing
2925 VFeedback from the modulating gas valve is too low
2927 BFlame failed during burner operation. Open the main shut off valve, shut down the appliance and check gas line, replace the ionisation electrode, set burner correctly and minimum rated load, check the integrity flue system and if the interconnected room air supply is too small, or the size of the ventilation opening is too small, clean the heating block on the flue gas side or replace the control unit/burner control unit
2946 VIncorrect code plug detected – the code plug needs replacing
2948 BNo flame signal. With low output the burner starts automatically after cleaning. If the fault occurs repeatedly, the setting of the CO2 valves need checking
2950 BNo flame signal. Following starting procedure the burner starts automatically. After cleaning set the correct gas / air ratio correctly
2963 BSignal from flow and heat exchanger temperature sensor outside the permissible range – the connecting lead needs connecting correctly
2964 BFlow rate in heat exchanger is too low
2965 BFlow temperature too high
2966 BFlow temperature rise in heat exchanger too rapid
2967 BFlow / heat exchanger temperature sensor differential too great
2970 BPressure drop in heating system too rapid
2971 BSystem pressure too low – the heating system needs venting or water needs topping up until the preset pressure is reached. Replace the cable to the pressure sensor replace the pressure sensor

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