Worcester Bosch Greenstar 12i System Fault codes & diagnostics

Your boiler has detected a general internal fault and has automatically stopped running to keep your system safe.

Your boiler's internal computer has suffered a critical failure and can no longer control the heating system.

Your boiler's computer has experienced an internal crash, meaning it can no longer safely operate or heat your home.

Your boiler has detected an internal safety issue and has shut itself down to prevent damage, meaning you currently have no heating or hot water.

Your boiler has encountered a general error and needs to be restarted to see if the system can clear the fault itself.

Your boiler has detected that it is getting too hot too often and has locked itself down as a safety precaution to prevent damage.

Your boiler's computer module does not match the specific model of your unit, preventing the system from starting up or operating correctly.

Your boiler's computer is reporting that an incompatible or incorrect internal control part has been installed, preventing it from functioning correctly.

Your boiler's main control unit has encountered a communication error and is unable to operate safely.

Your boiler's computer system is failing to communicate correctly, which has caused the unit to shut down for safety.

Your boiler's internal computer is failing to communicate with its memory chip, meaning it cannot start because it has forgotten its specific configuration settings.

Your boiler's internal memory key is not correctly recognized, which is preventing the system from starting up safely.

Your boiler is struggling to recognize its specific configuration settings, which is preventing it from starting up correctly.

Your boiler has detected that an incorrect internal identity part has been fitted, preventing it from functioning correctly.

Your boiler has identified an internal configuration mismatch, as the internal chip installed is designed for a different type of heating system than the one you are currently using.

Your boiler's computer components are not talking to each other correctly because one part is running outdated software, preventing the system from starting.

Your boiler is failing to light the flame properly and has safely locked itself out to prevent a gas build-up.

Your boiler has encountered an internal software or communication error that prevents it from operating safely or correctly.

Your boiler has detected that the internal fan is not moving air correctly, so it has safely shut down to prevent unsafe operation.

Your boiler is struggling to detect water moving through the system, which prevents it from heating your home safely.

Your boiler's internal computer has crashed and needs to be restarted to resume normal operation.

Your boiler is failing to ignite because it cannot detect a flame, meaning your heating and hot water will not work until it is fixed.

Your boiler has detected that the water inside is not circulating correctly, so it has safely shut down to prevent internal overheating.

Your boiler has detected an internal software or communication error that is preventing it from starting up correctly.

Your boiler has detected that the water inside has become dangerously hot and has shut itself down to prevent damage or overheating.

Your boiler's computer has detected that one of its internal sensors is sending back confusing or missing information, so it has shut down as a precaution to prevent system errors.

Your boiler’s computer is struggling to read internal electrical signals, which is preventing it from safely starting up.

Your boiler is struggling because the internal water pump is either jammed or trapped air is preventing it from circulating water properly to your radiators.

Your boiler has detected that the water pump responsible for circulating heat around your home has stopped working or is failing to provide a signal.

Your boiler is struggling to ignite the flame reliably, meaning it cannot start the heating cycle.

Your boiler has detected that the water returning to it is dangerously hot, causing it to shut down to prevent damage.

Your boiler has detected an electrical issue with the part that monitors the flame, preventing it from starting safely.

Your boiler is struggling to accurately measure its internal water levels because a wire has likely come loose or a small electronic sensor has failed.

Your boiler's control system has lost its ability to read the water pressure, causing it to stop operating to ensure safety.

Your boiler's internal computer is struggling to read its own sensors, which has caused it to shut down for safety to prevent incorrect heating operations.

Your boiler has detected a false flame signal even though it has switched off, so it has safely locked itself to prevent starting again.

Your boiler's water pump is unable to spin, which is preventing the hot water from circulating around your home.

Your boiler has detected that air is trapped inside the pump, preventing it from circulating water effectively to heat your home.

Your boiler's main control unit has lost its connection to the internal electronic system, which prevents it from operating correctly.

Your boiler's electronic control unit has identified an internal software or configuration lock that prevents it from starting up safely.

Your boiler has detected an issue with the sensor that tracks the water flow or temperature, meaning it cannot safely start your heating or hot water.

Your boiler has detected a communication error between its internal electronic brains, causing it to shut down for safety.

Your boiler has lost its electrical power connection while it was trying to protect itself from an internal error, meaning it needs a manual reset to get back up and running.

Your boiler is struggling to detect the water flowing through its internal pipes, which is causing it to stop heating as a safety precaution.

Your boiler has detected that the exhaust gases are getting too hot and has safely switched itself off to prevent damage.

Your boiler has detected an electrical fault in the sensor that monitors exhaust gases, so it has safely shut down to prevent incorrect operation.

Your boiler has detected that a key safety sensor has lost its connection, so it has safely shut itself down to prevent operation without proper monitoring.

Your boiler is struggling to perform its automatic safety check to ensure exhaust gases are leaving the house correctly.

Your boiler's computer is experiencing a software glitch or a communication failure between its internal control parts.

Your boiler is struggling to talk to its internal control system, which means it has stopped working to prevent any potential operating errors.

Your boiler is struggling to accurately measure the temperature of the water being heated for your taps and shower, so it has stopped producing hot water to prevent overheating.

Your boiler is having trouble communicating with the sensors responsible for heating your hot water, which means it may not be able to provide hot water at this time.

Your boiler's computer is struggling to get a steady power supply from your home's electricity, causing it to stop work to protect its internal parts.

Your boiler's computer module is failing to communicate correctly, which has caused the system to stop working entirely.

Your boiler is failing to detect the flame correctly, so it has safely shut itself down to prevent any issues with gas ignition.

Your boiler is struggling to circulate water, likely because the internal pump is jammed or there is air trapped inside the system.

Your boiler is struggling to circulate water because the internal pump is either jammed or not receiving enough water to function correctly.

Your boiler is struggling to move water around your heating system, which means it has stopped working to prevent itself from overheating.

Your boiler has detected an issue with the sensor that monitors exhaust gases, so it has safely shut down to prevent incorrect operation.

Your boiler's internal computer has lost contact with the main control panel, preventing it from starting up correctly.

Your boiler's internal computer chip does not match the control system it is plugged into, preventing the unit from starting correctly.

Your boiler's main control board has lost communication with an internal plug-in module or sensor, meaning it cannot currently operate.

Your boiler's main internal computer cannot find its unique identity chip, causing the system to stop working for safety.

Your boiler's computer has detected a serious internal fault that prevents it from operating safely, requiring a qualified professional to inspect or replace the electronic control system.

Your boiler's internal computer is malfunctioning and cannot communicate with the rest of the unit to operate your heating or hot water.

Your boiler's computer has encountered an internal communication error and has safely shut itself down to prevent potential issues.

Your boiler has stopped working for safety reasons and is waiting for you to manually restart it to try and clear the fault.

Your boiler's internal fan isn't spinning fast enough to safely clear away exhaust fumes, causing the system to shut down for your protection.

Your boiler has detected that air is not flowing through the system correctly, which is preventing it from running safely.

Your boiler has detected that the internal fan is spinning too slowly to safely clear waste gases, so it has shut down as a precaution.

Your boiler's main electronic brain has encountered a serious internal error and has shut itself down as a safety precaution.

Your boiler has detected that its internal air fan has been running non-stop for a full day, which is preventing the system from heating correctly.

Your boiler's internal fan is spinning faster than it should, which has caused the system to shut down for safety.

Your boiler has detected that the internal exhaust fan is spinning faster than it should, which is preventing the system from starting safely.

Your boiler's air circulation system isn't spinning fast enough to safely vent exhaust gases, so it has stopped working to prevent a risk.

Your boiler has stopped working because the internal component responsible for pushing air through the system is failing to start.

Your boiler's internal air intake system is failing to start, which prevents the unit from igniting to provide heating or hot water.

Your boiler has detected that it cannot move air through its internal system effectively, which has caused it to shut down for your safety.

Your boiler has stopped working because the water pressure inside your heating system has dropped too low to operate safely.

Your boiler has lost communication with the device that tells it how much water is inside, so it has shut down to prevent damage.

Your boiler is struggling because it cannot accurately tell how hot the water is as it flows back into the system.

Your boiler has lost the signal from the sensor that monitors the temperature of the water returning from your radiators, so it has stopped working to prevent damage.

Your boiler has detected that the water returning to it is too hot, causing it to shut down to prevent damage from overheating.

Your boiler is heating up much faster than normal and cannot distribute that heat away effectively, so it has shut down to prevent damage.

Your boiler has detected that the water inside the unit is getting too hot compared to the water travelling to your radiators, causing it to shut down to prevent damage.

Your boiler is shutting down because it cannot move the hot water away from the burner fast enough, causing it to overheat rapidly.

Your boiler's computer is experiencing an internal error and cannot communicate with its components, meaning it has shut down as a safety precaution.

Your boiler has detected a fault with the internal sensor that monitors the temperature of the water heading to your radiators, causing the system to shut down for safety.

Your boiler has detected an electrical fault with the internal sensor that monitors the flow of water, meaning it cannot safely regulate the temperature and has shut down to prevent damage.

Your boiler is struggling to detect water moving through it, meaning it has switched off to protect itself and will not provide heating or hot water until the issue is resolved.

Your boiler has lost the ability to accurately measure the temperature of the water flowing through your heating system, so it has shut down to prevent the system from getting too hot.

Your boiler has lost the connection to the component that monitors the temperature of the water circulating through your heating system, so it has shut down to prevent overheating.

Your boiler has detected that hot water is flowing in the wrong direction or circulating incorrectly, meaning it cannot heat your home properly.

Your boiler is having trouble 'reading' the temperature of the incoming water, which is causing it to stop operating correctly to prevent a potential error.

Your boiler has detected that the water inside the system is getting much hotter than it should be, so it has shut itself down to prevent damage.

Your boiler has detected that the water inside the unit is getting too hot, so it has safely shut itself down to prevent any damage.

Your boiler has sensed that it is getting dangerously hot and has shut itself down to prevent damage or overheating.

Your boiler has detected that it is running too hot or that the exhaust system is blocked, so it has safely shut itself down to prevent damage.

Your boiler has detected that it is running much too hot and has automatically shut itself down to prevent any damage or safety issues.

Your boiler has detected a faulty temperature sensor reading, so it has safely shut itself down to prevent overheating.

Your boiler has detected that a critical safety sensor is disconnected or faulty, so it has safely shut itself down to prevent overheating.

Your boiler has switched itself off because the water inside it has become dangerously hot.

Your boiler has detected that it is overheating and has automatically shut itself down to prevent internal damage.

Your boiler has tried to light several times but has been unable to detect a flame, causing the system to shut down for safety.

Your boiler has attempted to start but could not detect a flame, causing it to shut down for safety reasons.

Your boiler has stopped because it cannot detect a flame, meaning it can no longer produce heat or hot water safely.

Your boiler's internal electronic control center is having trouble communicating with the system, preventing the boiler from starting up safely.

Your boiler has tried to start four times but failed to light, so it has shut down as a safety precaution.

Your boiler has stopped while running because it can no longer detect the flame needed to heat your home.

Your boiler has lost its connection to the component that controls the gas supply, meaning it cannot ignite to provide heat or hot water.

Your boiler is trying to start but cannot detect a flame, so it has safely shut itself down to prevent gas buildup.

Your boiler has detected that the exhaust gases are getting too hot, too quickly, so it has turned itself off to prevent internal damage.

Your boiler has detected that hot gases are building up inside the system while the water meant to be heating your home is staying cold, so it has safely shut down to prevent overheating.

Your boiler has detected that the water inside isn't warming up as expected after it fires up, so it has stopped trying to prevent potential damage.

Your boiler has detected that it cannot move water through your radiators or pipes fast enough, causing the internal temperature to rise dangerously high.

Your boiler's computer has encountered a serious internal error and cannot communicate with its internal parts, meaning the system will remain off until it is reset or repaired.

Your boiler's internal computer has encountered a software or electronic error and can no longer control the heating properly.

Your boiler has detected a problem with the internal mechanism that controls the gas supply, meaning it has safely shut itself down to prevent any risk.

Your boiler's internal computer has suffered a critical failure and can no longer communicate with its own systems to safely run your heating or hot water.

Your boiler's main electronic brain is failing to communicate properly, which means it has safely shut itself down to prevent further damage.

Your boiler's internal computer has encountered a critical system error and is unable to operate safely or effectively.

Your boiler's main computer brain is having a critical error and cannot tell the unit how to operate, causing it to shut down for safety.

Your boiler's main computer brain has encountered a serious internal error and can no longer safely operate the heating system.

Your boiler has developed an internal electrical error and cannot safely operate its main computer system.

Your boiler's internal computer is experiencing an error and cannot process signals correctly, which prevents the unit from operating safely.

Your boiler has detected an internal safety check failure when starting up, meaning it cannot safely begin operation.

Your boiler is repeatedly trying to start but failing because it cannot sense the water flowing through the system properly.

Your boiler's internal computer is experiencing a critical error and can no longer safely control the heating system, meaning the boiler has shut down to prevent further issues.

Your boiler's electronic brain is unable to communicate properly, which means the system has safely shut itself down to prevent damage.

Your boiler thinks it can still see a flame inside even though it has been told to turn off, which is a safety conflict that prevents it from starting up again.

Your boiler has detected an internal software or hardware failure and is unable to operate safely, meaning you currently have no heating or hot water.

Your boiler has lost all electrical power and has shut down completely, so it is currently unable to provide heating or hot water.