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boiler service, boiler repair, emergency repair
Worcester 2000 25C Boiler Fault Codes
| Code | Category | Description | Remedy |
| 200 | O | The device is in central heating mode. | - |
| 201 | O | The appliance is in DHW mode. | - |
| 202 | O | The appliance is in optimised switching mode: the interval for restarting the burner has not yet expired ( service function 3-b2). | - |
| 203 | O | The appliance is on standby, there is no heat demand. | - |
| 204 | O | The current flow temperature is higher than the set flow temperature. The burner has been switched off. | - |
| 207 | - | Operating pressure too low. |
▶ Fill and vent the system, check the system for leaks. ▶ Replace pressure sensor if necessary. |
| 208 | O | The appliance is in chimney sweep mode. Chimney sweep mode is deactivated automatically after 30 minutes. | - |
| 212 | - | Temperature increase for safety or flow temperature sensor too fast. | ▶ Open the shut-off valves. |
| 214 | V | The fan stops during the safety time. | ▶ Check fan, replace if necessary. ▶ Check mains voltage. |
| 215 | V | Fan too fast. |
▶ Replace fan. ▶ Mains voltage must correspond to the default value. ▶ Check PCB and fan harness, replace if necessary. |
|
224 224 |
B V |
Flue gas temperature limiter or heat exchanger temperature limiter has tripped. |
If the blocking fault persists for a prolonged period, it becomes a locking fault. ▶ Check position of isolation valve in heating circuit, open if required. ▶ Check water pressure, if necessary top up until the preset pressure is reached. ▶ Check the temperature limiter and connecting lead of the heat exchanger for breaks, replace if required. ▶ Check the flue gas temperature limiter and the connecting lead for breaks, replace if required. ▶ Vent appliance with service function 4-A1 ( page 48). |
|
227 227 |
B V |
No flame detected. |
After the 5th ignition attempt, the blocking fault becomes a locking fault. ▶ Check whether the gas isolator is open. ▶ Check the gas supply pressure. ▶ Check ionisation signal. ▶ Check the power supply. ▶ Check the electrodes with cable, replace if required. ▶ Check the flue system, clean or repair if required. ▶ Check gas/air ratio, adjust if necessary. ▶ Clean heat exchanger. ▶ Check the gas valve, replace if required. ▶ Check burner setting, correct if necessary. |
| 228 | V | Flame signal is present although burner is switched off. |
▶ Check if there is a flame present. ▶ Check electrodes and connecting leads, replace if required. ▶ Check the gas valve, replace if required. ▶ Check appliance electronics, replace if necessary. |
| 229 | B | Flame lost during burner operation. |
▶ Check the main shut-off valve, open if necessary. ▶ Check the appliance isolation valve, open if necessary. ▶ Measure the gas supply pressure at the rated heat input. If necessary, shut down the appliance and check the gas line. ▶ Check flame sense electrode and connecting lead, replace if required. ▶ Check venturi/injector for potential blockage. ▶ Measure the ionisation current. ▶ Check the protective conductor connection in the control unit. ▶ Check the ignition cable for damage, replace if necessary. ▶ Check functionality of gas valve and replace if necessary. ▶ Check burner setting value at rated heat input. ▶ Check burner setting value at the lowest output. ▶ Check flue system. ▶ Check combustion air supply. ▶ Check the heat exchanger on the flue gas side for deposits, clean if necessary |
| 232 | B | Heat source locked by external switching contact. |
▶ Connect the plug for the external switching contact. ▶ Install jumper/check condensate pump according to manufacturer's specifications. ▶ Adapt switching point of the external temperature switch to the system. ▶ Replace connecting lead to the external temperature switch. ▶ Replace external temperature switch. |
| 233 | V | Fault in code plug or appliance electronics. |
▶ Check whether code plug is installed. ▶ Check appliance electronics, replace if necessary. |
| 234 | V | Electrical fault in gas valve. |
▶ Check the connecting lead, replace if required. ▶ Check the gas valve, replace if required. |
| 235 | V | Version conflict between appliance electronics and code plug. |
▶ Check software version of appliance electronics and code plug. ▶ Replace appliance electronics or code plug. |
| 237 | V | System fault. |
▶ Check and replace code plug. ▶ Check and replace the appliance electronics. |
| 238 | V | Appliance electronics faulty. | ▶ Check and replace the appliance electronics. |
| 242 | V | System fault, appliance electronics. |
▶ Reset control appliance / burner control unit - factory reset. ▶ Reconnect electrical connections at control unit / burner control unit correctly. ▶ Replace the control unit/burner control unit. |
| 244 | V | System fault, appliance electronics / basic controller. |
▶ Reset control unit / burner control unit - factory reset. ▶ Reconnect electrical connections at control unit / burner control unit correctly. ▶ Replace the control unit/burner control unit. |
|
246 247 257 |
- |
Internal burner control fault. |
▶ Reset burner control - factory reset. ▶ Check electrical connections of burner control. ▶ Replace burner control. |
|
245 249 250 251 252 253 254 |
V V V V V V |
System fault, appliance electronics. |
▶ Reset appliance electronics - factory reset. ▶ Check electrical connections. ▶ Replace the appliance electronics. |
| 256 | V | System fault, appliance electronics / basic controller. |
▶ Reset control unit / burner control unit - factory reset. ▶ Reconnect electrical connections at control unit / burner control unit correctly. ▶ Replace the control unit/burner control unit. |
| 258 | V | Internal fault in control unit. |
▶ Reset control unit - factory reset. ▶ Reconnect electrical connections at control unit correctly. ▶ Replace control unit. |
|
259 262 263 |
V V V |
System fault, appliance electronics. |
▶ Reset appliance electronics - factory reset. ▶ Check electrical connections. ▶ Replace the appliance electronics. |
| 264 | B | Air feed failed during operating phase. |
▶ Reconnect the fan plug properly, perform reset. ▶ Replace fan. ▶ Mains voltage must correspond to the default value. ▶ Remove any blockages in the flue system. ▶ Check venturi/injector for potential blockage. |
| 265 | BC | Heat energy demand lower than energy supplied. | - |
| 268 | - | Component test mode. | Not applicable, is status message. |
| 269 | V | Flame monitoring. |
▶ Reset appliance electronics - factory reset. ▶ Replace the appliance electronics. ▶ Check flame sense electrodes and connections. ▶ Check earth connections. |
| 270 | BC | The heat source has started up. | - |
| 273 | O | Operation interrupted: safety inspection following 24 hours of continuous operation. | - |
| 275 |
O |
Test code plug detected. | - |
| 281 | - | Pump stuck or running dry. |
▶ Replace the pump. ▶ Vent the system. ▶ Check operating pressure. ▶ Check low pressure switch. ▶ Check pump connections (hydraulic and electrical). |
| 305 | BC | Boiler cannot start temporarily following DHW priority. | System appliance only. |
| 306 | V | After switching gas off: Flame is detected. |
▶ Check the gas valve, replace if required. ▶ Check electrodes and connecting leads, replace if required. ▶ Replace the appliance electronics |
| 323 | - | Control communication fault. | - |
| 328 | V | Mains voltage briefly interrupted. | ▶ Check for voltage interruption between electrical wiring system of the building and the appliance |
| 341 | B | Heat source temperature increase too rapid. |
▶ Open isolation valves. ▶ Connect plug to pump. ▶ Replace pump. ▶ Ensure circulating pump is set on Constant speed mode - curve III. |
| 342 | BC | Temperature increase in DHW mode too rapid. |
▶ If the water pressure is too low, top up with water and vent the system. ▶ Open service valves in the cylinder charging circuit. ▶ Replace the diverter valve / cylinder primary pump. |
| 350 | B | Flow temperature sensor short circuit. |
▶ Check and replace flow temperature sensor and harness Section 13.2.1. ▶ Check and replace the connecting lead to the flow temperature sensor. ▶ Check and replace control unit/burner control unit. |
| 351 | B | Flow temperature sensor failure. |
▶ Connect the plug to the flow temperature sensor. ▶ Check and replace flow temperature sensor and harness Section 13.2.1. ▶ Check and replace the connecting lead to the flow temperature sensor. ▶ Check and replace control unit/burner control unit. |
| 356 | B | Supply voltage for heat source too low. | ▶ Establish supply voltage of at least 196 VAC. |
| 357 | BC | Venting program | - |
| 358 | BC | Active anti-seizing function. | Blocking protection for the heating pump and diverter valve active |
| 360 | V | Incorrect code plug | ▶ Check code plug, replace if necessary. |
| 362 | V | Service code plug detected. | ▶ Check code plug, replace if necessary. |
| 363 | V | System fault, appliance electronics: fault when testing the ionisation signal. |
▶ Check earthing connections. ▶ Reset appliance electronics, replace if necessary. |
| 364 | V | Solenoid valve EV2 leaking. |
▶ Check the gas valve, replace if required. ▶ Check electrodes and connecting leads, replace if required. ▶ Check and replace the appliance electronics. |
| 365 | V | Solenoid valve EV1 leaking. |
▶ Check the gas valve, replace if required. ▶ Check electrodes and connecting leads, replace if required. ▶ Check and replace the appliance electronics. |
| 604 | V | System fault, burner control unit. |
▶ Reset appliance - factory reset. ▶ If the fault persists following a reset, the burner control unit is faulty and must be replaced. |
| 810 | - | DHW temperature has not increased for 2 hours. |
▶ Prevent water from escaping. ▶ Position DHW temperature sensor correctly. ▶ If no voltage can be measured, then the MC10 control panel is faulty and must be replaced. ▶ If power is being supplied to the DHW cylinder charge pump but it is still not running, it is faulty and must be replaced. ▶ If power cannot be supplied to the DHW cylinder charge pump, then there is a problem in the cable between the control panel and pump. Check screw terminals and cables. ▶ If current is not being supplied to the 3-way valve, there is a problem in the cable between the control panel and valve. Check screw terminals and cables. ▶ If current is being supplied to the 3-way valve but it is still not working, the valve is faulty and must be replaced. ▶ If a voltage of approx. 230 V is measured at the terminals and the pump is not running, the pump is faulty and must be replaced. ▶ Eliminate all faults in the cables. Vent if necessary. ▶ Replace the pump if there are any deviations whatsoever. ▶ Set the DHW heating to “Priority”. ▶ If readings are different to the values in the table, replace the sensor. |
| 815 | R | Faulty low loss header temperature sensor. |
▶ Check the sensor port. ▶ Check the temperature sensor for incorrect installation position or breakage. |
| 1013 | R | Maximum combustion point reached. |
▶ Check plausibility of displayed cylinder temperature. ▶ Check plug-in connectors and cable harness for contact. ▶ Replace cylinder temperature sensor. |
| 1014 | - | Ionisation current is too low. | - |
| 1017 | R | Water pressure too low. |
▶ Check water pressure, if necessary top up until the preset pressure is reached. ▶ Check pressure sensor, replace if required. |
| 1018 | W | Service time expired. | ▶ Carry out maintenance. |
| 1021 | R | DHW temperature sensor faulty |
▶ Check plug, connect correctly. ▶ Check installation position of temperature sensor, mount correctly if required. ▶ Check temperature sensor, replace if necessary ( Tab. 36, page 75). ▶ Check connecting lead for breaks or short circuits, replace if required. ▶ Check and replace the appliance electronics. |
| 1022 | - | DHW temperature sensor is faulty | - |
| 1023 | R | Maximum operation time including standby is reached. | ▶ Perform inspection. |
| 1065 | R | Pressure sensor faulty or not connected. |
▶ Check plug, connect correctly. ▶ Check pressure sensor, replace if required. ▶ Check connecting lead for breaks or short circuits, replace if required. ▶ Check and replace the appliance electronics. |
| 1068 | R | Outside temperature sensor faulty. |
▶ Remedy contact problem. ▶ Replace the sensor. |
| 1073 | R | Flow temperature sensor short circuit |
▶ Check flow temperature sensor, replace if necessary. ▶ Check connecting lead for short circuits, replace if required. ▶ Check and replace the appliance electronics. |
| 1074 | R | No signal from the flow temperature sensor. |
▶ Check plug, connect correctly. ▶ Check flow temperature sensor, replace if necessary. ▶ Check connecting lead for breaks, replace if required. ▶ Check and replace the appliance electronics. |
| 1075 | R | Short circuit in heat exchanger temperature limiter. |
▶ Check heat exchanger temperature limiter, replace if required. ▶ Check connecting lead for short circuits, replace if required. ▶ Check and replace the appliance electronics. |
| 1076 | R | No signal from heat exchanger temperature limiter. |
▶ Check plug, connect correctly. ▶ Check heat exchanger temperature limiter, replace if required. ▶ Check connecting lead for breaks, replace if required. ▶ Check and replace the appliance electronics. |
| 2051 | - | Internal fault. |
▶ Disconnect power from the system for 30 seconds. ▶ Check and replace control unit. ▶ Notify customer service. |
|
2085 2908 |
V V |
Internal fault in burner control unit. |
▶ Reset appliance. ▶ If the fault persists following a reset, the burner control unit is faulty and must be replaced. |
| 2909 | - | System fault, appliance electronics / basic controller | ▶ If the fault persists following a reset, the burner control unit or Key (including interconnecting leads) is faulty and must be replaced. |
| 2910 | V | Fault in flue system. |
▶ Check whether a flue system is connected, install if required. ▶ Check for unobstructed cross-section of flue system, remove deposits if required |
| 2911 | - | Calibration failed. | ▶ Replace faulty component. |
| 2912 | - | No flame signal during calibration. | ▶ Replace faulty component. |
| 2913 | - | Flame signal too low during calibration. | ▶ Check and replace flame sense electrodes (and interconnecting leads). |
| 2914 | - | System fault, appliance electronics. | ▶ If the fault persists following a reset, the appliance control unit is faulty and must be replaced. |
| 2915 | V | System fault, appliance electronics. |
▶ Reset appliance. ▶ If the fault persists following a reset, the control unit is faulty and must be replaced. |
| 2916 | V | System fault, appliance electronics. |
▶ Reset appliance. ▶ Trigger heat demand. ▶ End heat demand. If the fault persists, the control unit is defective and must be replaced. |
| 2917 | V | No flame signal when checking the combustion control. |
▶ Disconnect power and then reconnect. ▶ Trigger heat demand. ▶ Wait 5 minutes. ▶ If the fault re-occurs within that time, reset the appliance without disconnecting the supply voltage. This triggers a calibration of the ionisation circuits. ▶ If the fault is still present after the calibration, the control unit is faulty and must be replaced. |
| 2918 | - | Fault in the flue. | ▶ Clean the siphon and drain water out of the appliance (gas side). |
| 2920 | V | Flame monitoring fault. |
▶ Check electrodes and connecting leads, replace if required. ▶ Check earthing connections. ▶ Check appliance electronics, replace if necessary. |
| 2921 | B | The appliance is in test mode ( Menu 5, page 49). | - |
| 2922 | - | Internal burner control fault. | ▶ Check and replace control unit. |
|
2923 2924 |
V V |
System fault, appliance electronics. |
▶ Reset appliance - factory reset. ▶ If the fault persists following a reset, the appliance electronics are faulty and must be replaced. |
|
2925 2926 |
V V |
System fault, appliance electronics. |
▶ Check the gas valve, replace if required. ▶ Check appliance electronics, replace if necessary. |
| 2927 | B | No flame detected during ignition. |
▶ Check the main shut-off valve, open if necessary. ▶ Check the appliance isolation valve, open if necessary. ▶ Measure the gas supply pressure at the rated heat input. If necessary, shut down the appliance and check the gas line. ▶ Check flame sense electrode and connecting lead, replace if required. ▶ Check venturi/injector for potential blockage. ▶ Measure the ionisation current. ▶ Check the protective conductor connection in the control unit. ▶ Check the ignition cable for damage, replace if necessary. ▶ Check functionality of gas valve and replace if necessary. ▶ Check burner setting value at rated heat input. ▶ Check burner setting value at the lowest output. ▶ Check flue system. ▶ Check combustion air supply. ▶ Check the heat exchanger on the flue gas side for deposits, clean if necessary |
| 2932 | - | Internal fault. | ▶ Restart the appliance. |
|
2928 2930 2931 2940 |
V V V V |
Internal fault in burner control unit. |
▶ Reset appliance - factory reset. ▶ If the fault persists following a reset, the burner control unit is faulty and must be replaced. |
| 2941 | B | Insufficient flow rate in heat source. |
▶ Check plug of flow temperature sensor, connect correctly if required. ▶ Check flow temperature sensor, replace if necessary. ▶ Check pump for blockage, clear if required. ▶ Check pump settings, correct if required. ▶ Check water pressure, if necessary top up until the preset pressure is reached. |
| 2942 | - | No fan speed feedback. |
▶ Connect plug for speed control to the fan. ▶ Connect plug for power supply to the fan. ▶ Check fan harness. ▶ Check and replace control unit |
| 2943 | - | Mains voltage too low | ▶ Establish supply voltage of at least 196 VAC. |
| 2945 | V | Too many short heat demands in a short time. |
▶ Reset appliance - factory reset. ▶ Increase restart blocking time. ▶ Make sure that at least one thermostatic valve is open. ▶ Check and replace faulty heating pump. ▶ Check diverter valve functionality, replace if necessary. |
| 2946 | V | Incorrect code plug. | ▶ Check code plug, replace if necessary |
| 2947 | R | Anti-seizing function is activated. | The function stops automatically. |
| 2948 | B | No flame signal with low output. |
The burner restarts automatically after purging. ▶ Check CO2 settings. |
| 2949 | B | No flame signal with high output. |
The burner restarts automatically after purging. ▶ Check burner gaskets, replace if required. ▶ Check CO2 settings. |
| 2950 | B | No flame signal following starting procedure. |
▶ Check CO2 settings, adjust if necessary. ▶ Check Burner and heat exchanger gaskets ▶ Check gas pressure during burning at full load ▶ Burner restarts automatically after purging |
| 2951 | V | Loss of flame too frequent. |
▶ Refer to the blocking error(s) that lead to this locking error. Check the fault history on appliance. ▶ Possible purging of gas pipe incomplete. ▶ Could also indicate a wide variety of issues such as pipework undersized or gas pressure dropping off, incorrectly routed condense drains, incorrectly sited flues, incorrectly wired etc. |
| 2952 | V | Internal fault when testing the ionisation signal. |
▶ Restart appliance to see if problem re-occurs. ▶ If the fault remains after resetting, the burner controller (PCB) is defective |
| 2953 | B | No flame signal with low output. |
The burner starts automatically after cleaning (purge).Possible cause high winds. ▶ If the fault occurs repeatedly, check the settings of the CO2 values. ▶ Check Flue integrity. ▶ Check flue terminal. |
| 2954 | B | No flame signal with high output. |
Burner restarts automatically after purging. ▶ Check and replace burner gaskets. ▶ Reduce burner load. ▶ If the fault occurs repeatedly, check the settings of the CO2 values. ▶ Check Flue integrity. ▶ Check flue terminal. |
| 2955 | B | The heat source does not support the specified parameters for the hydraulic configuration. |
▶ Check hydraulic configuration, correct if necessary. ▶ Check menu L2, default setting 0 required. |
| 2956 | O | Hydraulic configuration at the heat source is activated. | - |
|
2957 2958 |
V V |
System fault, appliance electronics. |
▶ Reset appliance electronics. ▶ Check electrical connections. ▶ Check and replace the control unit. |
|
2959 2960 |
B B |
System fault, appliance electronics. | ▶ Check and replace the control unit and code plug. |
|
2961 2962 |
V V |
No signal from fan. |
▶ Check mains voltage to fan. ▶ Check fan harness for continuity, replace if required. ▶ Check the Pulse width modulation (PWM). ▶ Check and replace the fan. ▶ Check and replace the PCB. |
| 2963 | R | The signal from the heat exchanger temperature limiter and flow temperature sensor is outside the permissible range. |
▶ Check flow through appliance and system is filled. ▶ Check for air locks in the system. Purge if required. ▶ Check Heat exchanger sensor (primary thermistor) and plug connected to stat. ▶ Check resistance of stat. Replace if required. ▶ Check continuity of harness. Replace if required. |
| 2964 | B | Insufficient flow rate in heat exchanger. |
▶ Supply sensor is not assembled on the supply pipe. ▶ Supply sensor does not make proper contact to the supply pipe. ▶ System is not filled with water. ▶ No water flow, because CH system is closed. ▶ No water flow, because pump is not operating correctly. |
| 2965 | B | Flow temperature too high. |
▶ Check flow through appliance and system pressure. ▶ Check for air locks in the system. Purge if required. ▶ Check isolation valves. |
| 2966 | B | Flow temperature increase in heat exchanger too rapid. |
▶ Check flow through appliance and system pressure. ▶ Check for air locks in the system. Purge if required. ▶ Check isolation valves. ▶ Check pump is operating freely, check voltage to pump |
| 2967 | B | Temperature differential between flow temperature sensor and heat exchanger temperature limiter is too great. |
▶ Check flow through appliance and system filled. ▶ Check for air locks in the system. Purge if required. ▶ Check isolation valves. ▶ Check pump is operating, check voltage to pump. ▶ Check heat exchanger sensor and flow sensor are making contact with the pipe work. ▶ Check heat exchanger sensor and resistance of stat. replace if required. ▶ Check continuity of harness. Replace if required. |
| 2968 | - | Refilling of system in progress. | Not applicable in the UK/IE |
| 2969 | - | Maximum number of refills reached. | Not applicable in the UK/IE |
| 2971 | V | Operating pressure too low. |
▶ Vent the heating system. ▶ Check water pressure, if necessary top up the system pressure. ▶ Check pressure sensor, replace if required. |
| 2972 | V | Mains voltage too low | ▶ Check mains supply voltage on appliance L and N connections. |
| 2973 | - | System fault, appliance electronics / basic controller |
▶ Perform reset - factory reset. ▶ Check and replace control unit. |
| 2974` | - | Internal error |
▶ Restart the appliance and check if fault remains. ▶ Check and replace control unit. |