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Worcester Bosch Greenstar 30i Boiler Error Codes

Fault code Fault

226

Service tool has been connected in the blocking error history menu

FD 231

The power has been interrupted during a lockout

C7 214

Fan does not run during the start up phase – fan harness connector needs checking

C6 215

Fan speed too high – check the fan harness and connector

C7 216

Fan speed too low – check the fan harness and connector

C7 217

Fan has stopped during appliance operation

C1 264

Fan stopped during operation

C4 273

Continuous fan operation for the last 24 hours – appliance temporarily blocked

E2 222

Flow temperature sensor shorted

E2 233

Flow temperature sensor disconnected

E9 276

Primary flow temperature exceeded 95°c

E2 350

Flow temperature sensor shorted

E2 351

Flow temperature sensor disconnected

FA 306

Ionisation detected after the gas valve closed

EA 227

No ionisation detected after ignition

F7 228

Isioniation current detected before burner start

EA 229

Loss of ionisation signal during operation

EA 261

Heat control module (HCM) potentially defective – reset the appliance

9U 233

Control box or heat control module (HCM) is defective or loose, the HCM needs to be checked

C4 237

Control box or heat control module (HCM) is defective

F0 238

Gas valve or control box error – gas valve coils need checking

F0 239

Control box or the heat control module (HCM) is defective – the control box connections need checking

F0 242

Control box or the heat control module (HCM) is defective – the HCM and control box connections need to be checked

B7 257

Control box or the heat control module HCM) is defective- the HCM and control box connections need to be checked

F0 258

Control box or the heat control module (HCM) is defective – HCM or control box connections need to be checked

EH 258

Control box or the heat control module (HCM) is defective – HCM or control box connections need to be checked

F1 259

Control box or the heat control module (HCM) is defective – HCM or control box connections need to be checked

F0 262

Control box or the heat control module (HCM) is defective – HCM or control box connections need to be checked

F1 263

Control box or the heat control module (HCM) is defective – HCM or control box connections need to be checked

F0 272

Control box or the heat control module (HCM) is defective – control box and connections need checking or HCM might not be inserted properly and need replacing

F0 280

Control box or the heat control module (HCM) is defective – control box and connections need checking or HCM might not be inserted properly and need replacing

F0 290

Control box is defective – HCM needs checking as it might not be inserted properly or need replacing

328

Internal error with the mains voltage – frequency may be inconsistent

235

Incompatible heat control module (HCM) software versions – control box needs latest software

356

Low mains voltage – the voltage may be interrupted or inconsistent and needs checking

360

Heat control module (HCM) invalid – the inserted HCM does not correspond with the control box

A8 362

Low mains voltage – the voltage may be interrupted, inconsistent or heat control module (HCM) invalid

CC 800

Outdoor sensor defect available when accessory outdoor sensor is connected

A1 281

Pump stock or running dry

E9 224

Flue or high limit thermostat activated

D4 341

Primary flow temperature rising too fast

Worcester Bosch Highflow 440 & 550 Combi Boiler Error Codes

Fault code Fault

A1

Service tool has been connected in the blocking error history menu

A5

The power has been interrupted during a lockout

A7

Fan does not run during the start up phase – fan harness connector needs checking

A8

Fan speed too high – check the fan harness and connector

B1

Fan speed too low – check the fan harness and connector

B2, B3, B4, B5, B6

Fan has stopped during appliance operation

B7

Fan stopped during operation

C6

Continuous fan operation for the last 24 hours – appliance temporarily blocked

D3

Flow temperature sensor shorted

D5

Flow temperature sensor disconnected

D6

Primary flow temperature exceeded 95°c

EA

Flow temperature sensor shorted

E2

Flow temperature sensor disconnected

E9

Ionisation detected after the gas valve closed

F0

No ionisation detected after ignition

F1

Isioniation current detected before burner start

F7

Loss of ionisation signal during operation

FA

Heat control module (HCM) potentially defective – reset the appliance

FD

Control box or heat control module (HCM) is defective or loose, the HCM needs to be checked

Worcester Bosch Greenstar 18 & 24Ri Boiler Error Codes

Fault code Fault

No light

No power at control board

Light on

Appliance on but not operating during demand

Slow flash (mostly off flashes on)

Ignition lockout

Slow flash (mostly on flashes off)

Flue overheat or heat exchanger overheat

Fast flash

Volatile lockout sensor fan or code plug

2 pulses

Check service mode switch is in minimum position

5 pulses

Check service mode switch is in max position

Worcester Bosch Greenstar 8000 life Boiler Error Codes

Fault code Fault

200 O

Boiler in heating mode

201 O

Boiler in hot water mode

202 O

Boiler in anti-cycle mode

203 O

Boiler in standby – no heat energy demand

204 O

Current primary water temperature higher than set value

208 O

Chimney sweep demand

224 V

Safety temperature limiter has tripped – top-up water until the reset pressure is reached

227 V

No flame signal after ignition burner control unit could need replacing

228 V

Flame signal without flame present – air/gas ratio control valve may need replacing as might the ionisation cable

305 0

Boiler in hot water anti-cycle mode

306 V

Flame signal after closing the fuel supply – the air/gas ratio control valve might need replacing

360 V

Incompatible code plug – check if a correct code plug is installed and exchange or reconnect code plug

815 W/B

Low loss header temperature sensor faulty – check the sensor port or check the differential sensor for incorrect installation position or breakage

1010 O

No 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 W

Water pressure too low – the water needs topping up and the vent system or pressure sensor may need replacing

1021 B

Hot water temperature sensor is defective – the plug to the hot water temperature sensor may not be connected

1022 B

Hot 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 W

Outside temperature sensor is defective – check the connecting lead

1065 B

Pressure sensor defective or not connected – check pressure sensor connection as it may need replacing

1068 W

Outside temperature sensor defective – check the connecting lead

1073 W

Short circuit of the flow temperature sensor – the temperature sensor may need replacing

1074 W

No signal from the flow temperature sensor available – connect the plug to the flow temperature sensor correctly or temperature sensor could need replacing

1075 W

Short circuit of the temperature sensor at the heating block – temperature sensor may need replacing

1076 W

No signal from the temperature sensor at the heating block available – replace the temperature sensor, the connecting lead or the control unit

2920 V

Error with the flame monitoring

2924 V

No 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 V

Feedback from the modulating gas valve is too low

2927 B

Flame 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 V

Incorrect code plug detected – the code plug needs replacing

2948 B

No 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 B

No flame signal. Following starting procedure the burner starts automatically. After cleaning set the correct gas / air ratio correctly

2963 B

Signal from flow and heat exchanger temperature sensor outside the permissible range – the connecting lead needs connecting correctly

2964 B

Flow rate in heat exchanger is too low

2965 B

Flow temperature too high

2966 B

Flow temperature rise in heat exchanger too rapid

2967 B

Flow / heat exchanger temperature sensor differential too great

2970 B

Pressure drop in heating system too rapid

2971 B

System 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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Safety Warning

When your Worcester boiler error codes or fault lights flash, don’t do any repair work that involves working with gas as you are required to be Gas Safe Registered by law.

Here at Boiler Plan all our engineers are Gas Safe Registered and will do an amazing job with any Worcester Bosch boiler repair work you may need.

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