BoilerFaultCodes.com

Worcester Bosch Greenstar CDi Compact Fault Codes

Combi Natural GasLPG 28-36 kW 2012-present
GC Numbers: 47-114-9247-114-9347-114-94

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Most common fault codes

1.C
Your boiler is struggling to pump water around your home correctly because it cannot find the right speed setting for your heating system.
Gas Safe engineer required · £250-450
1.d
Your boiler has detected that the internal pump is not rotating at the correct speed to circulate water through your heating system.
Gas Safe engineer required · £220-450
1.E
Your boiler's internal pump is detecting a communication error or is set to the wrong operating mode, meaning it cannot circulate water properly.
Gas Safe engineer required · £180-350

All 132 fault codes

Code Severity Plain English
1.A Low Your boiler is temporarily running at its maximum power level, which is usually a normal setting used by engineers during testing or after a reset.
1.b Low Your boiler is currently running at its maximum power level to provide hot water and this code is often just an operational status indicator rather than a breakdown.
1.C High Your boiler is struggling to pump water around your home correctly because it cannot find the right speed setting for your heating system.
1.d High Your boiler has detected that the internal pump is not rotating at the correct speed to circulate water through your heating system.
1.E High Your boiler's internal pump is detecting a communication error or is set to the wrong operating mode, meaning it cannot circulate water properly.
2.b High Your boiler has sensed that the water inside is getting too hot too quickly and has shut down as a safety precaution.
2.C Low Your boiler is currently running an automated sequence to remove trapped air from the system, which typically occurs after you first turn the power on or restart the unit.
2.F Low Your boiler is in a normal operating mode, likely a service mode or a temporary state where it is monitoring its internal temperature sensors.
3.b Low Your boiler is taking a short, programmed rest to prevent itself from switching on and off too frequently, which helps protect the internal components from unnecessary wear.
3.C Medium Your boiler is heating up too quickly and has paused itself to prevent over-heating, which often suggests there is a problem with the water circulating through the system.
3.E High Your boiler is struggling to provide hot water because it is overheating and shutting down too quickly during its operation cycle.
3.F Medium Your boiler has detected an error while turning off the burner after you used your hot water taps, which may prevent it from firing up again.
4.F Low Your boiler is performing a routine automatic cleaning and filling cycle of its internal drainage system, which is a normal process and not actually a fault.
5.A Low Your boiler is simply reminding you that its annual service is now due, and it does not indicate a breakdown or a safety fault.
5.b Medium Your boiler's fan is running longer than it should after the heating has turned off, which is usually a sign of a communication error between internal components.
6.A High Your boiler has failed to ignite properly, meaning it cannot create a flame to provide heating or hot water.
6.d High Your boiler has detected an issue with the sensor that tracks the flow of hot water, which may cause your hot water to stay cold or run inconsistently.
6.E High Your boiler is having trouble communicating with the internal clock or plug-in timer, preventing it from knowing when to turn on.
8.A High Your boiler's internal computer has lost its identity because the memory chip is either loose or failing.
8.b High Your boiler's internal configuration chip has been disconnected or is not being recognised correctly by the control board.
8.C High Your boiler has detected an internal communication error between its electronic control components and is unable to start for safety reasons.
8.d High Your boiler has detected an internal electronics communication error, which has caused it to stop working for safety.
8.E High Your boiler's internal memory has encountered an error and has reverted to its factory default settings, meaning it needs reconfiguring to work with your heating system.
8.F Emergency Your boiler has detected a flame when there shouldn't be one, which usually means a internal component is stuck or damaged.
9.A Low Your boiler's control panel has been set to stay on permanently, which means it isn't following your usual heating schedule or thermostat settings.
9.b High Your boiler's fan is not spinning at the correct speed, which prevents the system from safely starting the combustion process.
9.C Low Your boiler is displaying its current power level because a technician is likely testing the system or a specific testing mode has been left on.
9.d High Your boiler is failing to start because the internal fan is not spinning at the speed required to clear waste gases.
9.E High Your boiler is struggling to detect when you turn on a hot tap, meaning you might have inconsistent or no hot water.
9.F Low Your boiler's internal pump is running longer than it should after the heating has switched off, which often indicates a communication error or a trapped signal.
9A High Your boiler has stopped working because the internal pump that moves water around your heating system has become stuck or failed.
51122 Medium Your boiler is confused because the wrong type of temperature sensor has been plugged into the system, meaning it can't accurately monitor your hot water cylinder.
51123 Low The system has detected that the wrong type of temperature sensor has been installed for your solar heating circuit.
51132 Medium Your boiler has lost communication with the temperature sensor that monitors your hot water cylinder, meaning it may not know when to stop heating your water.
51133 Low Your boiler has detected a fault with the solar collector temperature sensor, meaning it cannot correctly monitor heat coming from your solar panels.
52124 High Your boiler's internal temperature sensors have likely been plugged into the wrong sockets or have developed a wiring fault, meaning the system cannot accurately track how hot the water is.
53125 Medium Your boiler's solar heating sensor has detected an unusually high temperature or a technical fault, causing the system to stop as a precaution.
54145 Low Your boiler’s solar hot water system hasn't reached the high temperature needed to properly disinfect the cylinder, often because a cleaning cycle was interrupted or a pump is struggling.
55146 Low Your boiler's built-in solar water heating software has been activated, but the solar system hasn't been set up or configured correctly for use.
56147 Medium Your boiler's internal pump or a control valve has been accidentally switched to a manual setting and is no longer being controlled automatically by the boiler.
59201 Low Your solar heating system is circulating liquid too quickly, which usually means a sensor is misreading or the pump speed needs adjusting.
59202 Low Your solar heating system is not circulating fluid quickly enough between the roof panels and your boiler setup.
A1 High Your boiler is struggling to move water because there is air trapped in the system or the water pressure has dropped too low.
A5 High Your boiler's temperature sensor responsible for monitoring the hot water storage is faulty or has lost connection, meaning the system cannot safely heat your water.
A6 Medium Your boiler has lost communication with the safety sensor that prevents your underfloor heating system from getting too hot.
A7 Medium Your boiler has lost the ability to measure the temperature of your hot water properly, which usually means your taps will only run stone cold or may fluctuate wildly in temperature.
A8 High Your boiler has lost its connection with the thermostat, meaning they are no longer speaking to each other to control your heating.
b1 High Your boiler’s internal computer has lost contact with a small identification chip that tells it how to operate correctly.
C6 High Your boiler has detected that the internal fan is spinning too fast, causing the system to shut down for safety.
CC Low Your boiler has lost its connection to the sensor that monitors the temperature outside, which helps it run more efficiently.
E2 High Your boiler has detected a faulty internal temperature sensor, which means it cannot accurately measure how hot the water is and has stopped running for safety.
E9 High Your boiler is overheating because the water inside is heating up too quickly, causing the system to shut down temporarily for safety.
EA High Your boiler has stopped working because it cannot detect a flame, meaning there is likely a disruption to the gas supply or an issue with the ignition process.
F0 High Your boiler's internal computer has encountered a critical electronic glitch that is preventing it from running safely.
F7 High Your boiler thinks there is still a flame burning even though it has commanded the system to turn off, causing it to shut down for safety.
FA Emergency Your boiler thinks it still sees a flame even though it has commanded the gas to turn off, which is a safety conflict.
Fault 01 / 200 High Your boiler's internal computer has lost communication with its control components, meaning it cannot receive or send the signals needed to operate.
Fault 01 / 201 High Your boiler's internal computer is having trouble communicating with an external control or smart thermostat connected to it.
Fault 02 / 40 High Your boiler's computer brain has become confused and is no longer recognising its own internal components.
Fault 02 / 42 High Your boiler's main control chip is not making a proper connection, meaning the 'brain' of the appliance cannot communicate correctly.
Fault 02 / 43 High Your boiler's main control unit is confused because a small internal configuration plug has moved or is failing, causing the system to lock out for safety.
Fault 02 / 100 High Your boiler's main control unit is having a communication breakdown with its internal safety components, meaning it cannot operate safely and has shut down.
Fault 02 / 205 High Your boiler's internal memory has encountered a glitch, causing some of its important settings to reset themselves to the factory defaults.
Fault 02 / 255 High Your boiler's internal computer has encountered a critical error and can no longer communicate with the heating controls, causing the system to stop working.
Fault 03 / 20 Medium Your boiler is having trouble communicating with the temperature thermostat built into its control panel, which means it doesn't know how warm your home is.
Fault 03 / 21 Medium Your boiler's built-in thermostat controls has developed an electrical fault and can no longer tell how warm your room is.
Fault 11 / 131 High Your boiler has detected a new internal electronic component or communication device and requires a manual reset to confirm and sync the system.
Fault 11 / 132 High Your boiler has detected a change in its internal electronic communication system or a new part, and it needs to be officially acknowledged before it will start again.
Fault 12 High Your hot water tank has overheated and a safety switch has shut the system down to prevent damage.
Fault 12 / 170 High Your boiler's internal computer has lost communication with a central safety component or an external controller, causing the system to shut down for safety.
Fault 12 / 171 High Your boiler has lost communication with its internal electronic controls or a safety switch has triggered to prevent overheating.
Fault 13 / 157 High Your boiler's computer system has detected a change in its connected parts or settings and needs to be told how to recognize them again.
Fault 13 / 158 High Your boiler's computer is confused because it thinks a new component has been plugged in or a setting has changed, and it needs to be told how to work with the updated system.
Fault 13 / 159 High Your boiler's computer is confused because it has detected a change in its connected control components and needs to be told how to work with them again.
Fault 14 / 117 Medium Your boiler is having trouble communicating with an external control or thermostat that isn't compatible with it.
Fault 14 / 118 High Your boiler's internal computer has lost communication with its connected hot water or smart control components due to a settings mismatch.
Fault 14 / 119 High Your boiler's internal computer is having trouble communicating with an external plug-in control or a hot water cylinder component.
Fault 15 / 30 Low Your boiler has lost communication with its outdoor weather sensor, meaning it cannot automatically adjust your heating based on the temperature outside.
Fault 19 / 202 High Your boiler's internal computer is trying to communicate with a part or an external controller that it can no longer find or recognize.
Fault 20 / 193 High Your boiler's computer and its remote control are having trouble speaking the same language, causing the system to stop working correctly.
Fault 29 / 202 High Your boiler's internal computer has lost communication with one of its key control modules, meaning it cannot save or follow its programmed settings.
Fault 29 202 High Your boiler is having trouble 'talking' to its internal controls or external thermostat, meaning it cannot receive the correct instructions to heat your home.
Fault 30 / 7 High Your boiler has detected a problem with a temperature sensor that controls the heat of your water, which might cause your heating or hot water to stop working correctly.
Fault 30 7 High Your boiler is having trouble managing the temperature of its internal water circuits, which will likely stop your heating and hot water from working correctly.
Fault 33 / 22 High Your boiler's computer is confused because it thinks internal temperature sensors are plugged into the wrong place, preventing the unit from operating safely.
Fault 33 22 High Your boiler has stopped working because its internal control board has detected that some wiring or sensors have been plugged into the wrong ports during a service or repair.
Fault 40 / 101 High Your boiler has detected an electrical fault with one of its internal temperature sensors, which is preventing it from monitoring heat levels safely and will likely stop it from working.
Fault 40 / 102 High Your boiler has detected a broken wire or a faulty connection to one of the internal temperature sensors, which is preventing it from heating properly.
Fault 40 101 High Your boiler has detected an electrical fault with its main temperature sensor, causing the system to shut down safely to prevent overheating.
Fault 40 102 High Your boiler has lost connection with a temperature sensor, which means it cannot accurately monitor the water temperature to operate safely.
Fault 41 / 103 Low Your boiler has detected an electrical problem with the sensor that measures the temperature at the bottom of your solar hot water cylinder.
Fault 41 / 104 Medium Your boiler's hot water system has lost communication with the temperature sensor in your solar cylinder, meaning it cannot accurately monitor the water temperature.
Fault 41 103 Medium Your boiler has stopped providing hot water correctly because a temperature sensor connected to your solar heating system has developed an electrical fault.
Fault 41 104 Medium Your boiler is struggling to read the temperature of the water in your solar cylinder due to a broken or faulty sensor or connection.
Fault 50 Medium Your solar heating system has stopped circulating fluid properly, likely due to a blockage or trapped air bubbles within the pipes.
Fault 50 / 121 Low Your solar heating system is unable to move water because the pump is stuck or there is an air bubble trapped inside the pipes.
Fault 50 121 Medium Your solar heating pump has stopped moving because something is physically blocking it from spinning internally.
Fault 50 126 Low Your solar heating system has stopped working properly because either air is trapped in the pipes or the circulation pump has become stuck.
Fault 50 140 Medium Your solar heating system is unable to move water because the pump is stuck or there is an air pocket trapped in the pipes.
Fault 51 / 122 Medium Your boiler has detected that the wrong type of temperature sensor has been plugged into the system control board.
Fault 51 / 123 Medium Your boiler has detected that an incorrect or incompatible temperature sensor has been installed, meaning it cannot properly monitor the system's heat levels.
Fault 51 / 132 Medium Your boiler has detected that the wrong type of sensor has been installed or connected for your hot water system, causing a communication error within the internal electronics.
Fault 51 / 133 High Your boiler has detected that an incorrect or incompatible internal sensor has been fitted, preventing it from reading temperatures accurately.
Fault 51 122 Medium Your boiler has detected that the wrong type of temperature sensor has been installed or configured for your hot water cylinder.
Fault 51 123 Medium Your boiler has detected that the wrong type of temperature sensor has been installed or configured for your hot water system.
Fault 51 127 Medium Your boiler's control system has detected that the wrong type of temperature sensor has been installed or configured for your hot water system.
Fault 51 132 Medium Your boiler has lost communication with the temperature sensor that monitors your hot water cylinder, meaning it cannot accurately heat your water.
Fault 51 133 Low Your boiler's internal sensor has detected a communication issue with your solar heating system, meaning the solar panels aren't currently helping to heat your water.
Fault 52 / 124 High Your boiler has detected that its internal temperature sensors are reading heat in the wrong order, causing the system to shut down for safety.
Fault 52 124 High Your boiler has become confused because its internal temperature sensors appear to have been plugged into the wrong ports or are reading backwards.
Fault 53 / 125 High Your boiler has detected that a temperature sensor is installed in the wrong place, meaning the system cannot accurately monitor the heat coming from your solar panels or heating circuit.
Fault 53 125 Low Your boiler's solar heating sensor has detected an issue, likely meaning your solar panels aren't assisting with your hot water production as they should.
Fault 53 128 High Your boiler has detected that a temperature sensor is sending an unusual reading, suggesting it may have been knocked out of place or is reporting a sudden, impossible heat spike.
Fault 54 Low Your boiler's automatic routine to heat your solar hot water tank to a safe, bacteria-killing temperature has failed to complete.
Fault 54 / 145 Low Your boiler is warning you that your solar-heated water tank hasn't reached a high enough temperature to safely kill off any potential bacteria.
Fault 54 145 Low Your solar hot water system hasn't reached the high temperature needed to kill bacteria, usually because the solar pump is struggling or the settings are incorrect.
Fault 55 / 146 Low Your boiler is displaying an advisory message stating that its built-in solar heating controls have not been set up or activated.
Fault 55 146 Low Your boiler is trying to communicate with solar heating equipment that hasn't been set up yet or has had its settings lost.
Fault 56 / 147 High Your boiler's internal pump settings have been switched to a manual override mode, preventing it from operating automatically as it should.
Fault 56 147 High Your boiler's internal pump has been left in a manual testing mode, meaning it isn't responding correctly to your heating demands.
Fault 56 154 High Your boiler's internal pump has been manually overridden or is stuck in a manual operation mode, which is preventing it from working automatically to heat your home.
Fault 59 / 201 Low Your solar heating system is moving water too quickly or too slowly, which means it cannot heat your water efficiently.
Fault 59 / 202 Low Your boiler has detected an issue with the speed at which liquid is moving through your solar heating panels, meaning the solar water heating system is not working efficiently.
Fault 59 201 Low Your solar heating system is moving fluid too quickly through the roof collectors, which may indicate a settings error or a faulty sensor.
Fault 59 202 Medium Your solar heating system isn't circulating fluid properly, which means the sun's energy isn't being transferred to your water tank as it should.
Fd Low Your boiler's reset button has been pressed incorrectly or held down for too long, causing a temporary communication error.
P1 Low Your boiler is stuck in a low-power service mode, meaning it will provide heat but won't reach full power or respond to normal temperature demands.
P2 Medium Your boiler is stuck in a service mode where it runs at maximum power constantly, which is usually triggered during maintenance or testing.
P3 Low Your boiler is currently running a self-cleaning routine to remove trapped air bubbles from the internal pipes and pump.
P4 Low Your boiler is currently running a routine internal cleaning cycle to fill up its condensation trap and is not actually broken.
PC Low Your boiler is working normally, but it is displaying a reminder that its annual service is now due because the programmed operating hours have been reached.
SE Low Your boiler is simply displaying a reminder that its annual service is due soon or is now overdue.

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