Worcester Bosch Greenstar boilers show a two-character fault code such as EA, E9 or C6. Newer Greenstar 8000 models can show numbered faults instead, such as 2980. Find your code below.
EA is the Worcester code people search for most. Worcester says it can mean no gas supply, a blocked or frozen condensate pipe, or a blocked flue.
| Code | What it means | Models | Can you fix it? |
|---|---|---|---|
| EA | Flame not detected. | Greenstar CDi Classic | Checks first |
| E9 | The safety temperature limiter in the heating flow has tripped. | Greenstar CDi Classic | No, engineer only |
| C6 | Fan speed too low. | Greenstar CDi Classic | No, engineer only |
| A8 | Lost communication with the boiler's controls. | Greenstar CDi Classic | No, engineer only |
| F7 | Flame detected even though the boiler is switched off. | Greenstar CDi Classic | No, engineer only |
| FA | Flame detected after the gas was shut off. | Greenstar CDi Classic | No, engineer only |
| 2980 | Fault 2980 on Greenstar 8000 models. | Greenstar 8000+ | No, engineer only |
| 214 | Fan shut down during safety time. | Greenstar 4000 | No, engineer only |
| 224 | Varies by model: maximum flue gas thermostat or heat exchanger maximum thermostat has activated (Greenstar 4000); safety temperature limiter has tripped (Greenstar 8000 Life). | Greenstar 4000, Greenstar 8000 Life | No, engineer only |
| 227 | No flame signal after ignition. | Greenstar 4000, Greenstar 8000 Life | Checks first |
| 228 | Flame signal without flame present. | Greenstar 4000, Greenstar 8000 Life | No, engineer only |
| 229 | Flame failed during burner operation. | Greenstar 8000 Life | Checks first |
| 232 | Boiler locked by external switching contact. | Greenstar 4000 | No, engineer only |
| 306 | Flame signal after closing the fuel supply. | Greenstar 8000 Life | No, engineer only |
| 360 | Incompatible code plug. | Greenstar 8000 Life | No, engineer only |
| 815 | Low loss header temperature sensor faulty. | Greenstar 8000 Life | No, engineer only |
| 1010 | No BUS communication: EMS bus cable not connected correctly or damaged. | Greenstar 8000 Life | No, engineer only |
| 1017 | Water pressure too low. | Greenstar 8000 Life | Usually yes |
| 1021 | Hot water temperature sensor defective. | Greenstar 8000 Life | No, engineer only |
| 1037 | Outside temperature sensor defective. | Greenstar 8000 Life | No, engineer only |
| 1065 | Pressure sensor defective or not connected. | Greenstar 8000 Life | No, engineer only |
| 1068 | Outside temperature sensor defective. | Greenstar 8000 Life | No, engineer only |
| 1073 | Short circuit of the flow temperature sensor. | Greenstar 8000 Life | No, engineer only |
| 1074 | No signal from the flow temperature sensor. | Greenstar 8000 Life | No, engineer only |
| A7 | Hot water temperature sensor defective. | Greenstar CDi Classic | No, engineer only |
| b1 | Code plug not detected. | Greenstar CDi Classic | No, engineer only |
| E2 | Central heating flow temperature sensor defective. | Greenstar CDi Classic | No, engineer only |
| F0 | Internal error. | Greenstar CDi Classic | No, engineer only |