Worcester Bosch Greenstar 4000 Fault codes & diagnostics

Your boiler has detected that the internal exhaust fan has failed to start or stopped unexpectedly, so it has safely turned itself off to prevent a buildup of fumes.

Your boiler has detected that it is running dangerously hot and has shut itself down to prevent internal damage.

Your boiler is trying to start but the flame is failing to light or stay lit, so it has safely shut itself down to prevent a gas build-up.

Your boiler has lost the ability to communicate with its internal control system, meaning it has safely shut itself down to prevent operational errors.

Your boiler has detected an electrical issue with its internal gas supply system, meaning it cannot safely ignite to provide heating or hot water.

Your boiler's internal computer chips are failing to communicate correctly because they do not recognise each other as compatible parts.

Your boiler is struggling to detect consistent water flow correctly, preventing it from safely heating your home or water.

Your boiler's internal computer is experiencing a critical error and cannot communicate properly to operate your heating or hot water.

Your boiler has detected an internal electrical communication error, which means it has safely shut down to prevent further damage.

Your boiler's internal computer is experiencing a communication error, meaning it has safely shut itself down to prevent potential damage.

Your boiler's internal computer is experiencing a temporary communication error, causing it to stop operating as a protective measure.

Your boiler's internal computer has encountered a critical communication error, meaning it has safely shut itself down to prevent potential damage.

Your boiler’s internal computer is experiencing a software glitch or a communication error that is preventing it from running safely.

Your boiler's internal computer is experiencing a communication error, meaning it has safely shut down to prevent incorrect operation.

Your boiler's computer has encountered an internal error and cannot operate, which means you currently have no heating or hot water.

Your boiler has detected an internal electrical problem with its main computing brain, preventing it from operating safely.

Your boiler has detected an internal communication error and has safely shut down to prevent potential damage to its electronic components.

Your boiler's internal computer is experiencing a software or communication error and needs to be restarted or investigated by a professional.

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

Your boiler's internal computer has encountered a memory or communication error, which prevents it from operating safely.

Your boiler has performed an internal self-check on its safety switches and identified a mismatch in the relay system.

Your boiler is struggling to detect the flame needed to heat your home, so it has safely shut itself down to prevent any issues with gas flow.

Your boiler has detected that it cannot safely ignite or maintain its flame, so it has automatically shut down to prevent any risk.

Your boiler has detected that the internal components responsible for burning fuel and venting gases have stopped working as expected, causing the system to shut down for safety.

Your boiler is having difficulty managing the internal gas and air supply needed to start a flame, causing it to shut down for safety.

Your boiler has identified an internal system fault that requires a professional to safely reset and verify that it is operating correctly.

Your boiler's internal computer is experiencing a temporary communication error or software glitch that is preventing it from operating correctly.

Your boiler's computer is having trouble recognising its internal configuration, which is preventing the system from starting up safely.

Your boiler's internal computer is experiencing a communication error or technical glitch that is preventing it from operating correctly.

Your boiler is failing to heat your water, which usually points to a sensor or valve issue preventing the hot water mode from activating.

Your boiler's electronic control panel is currently unable to send or receive signals, causing the system to stop operating to prevent errors.

Your boiler has detected that it is running too hot while attempting to fire up and has temporarily shut itself down to prevent damage.

Your boiler has lost the water pressure needed to operate and needs to be topped up to work again.

Your boiler has detected that the water pump is either not communicating properly or is the wrong type for your specific model, which prevents the system from circulating heat effectively.

Your boiler is currently struggling to correctly measure the water pressure in your heating system, which prevents it from operating safely.

Your boiler's temperature sensor is providing an incorrect reading because of a faulty electrical connection, causing the system to stop heating for safety reasons.

Your boiler has lost the ability to read the temperature of the water inside it, so it has shut down as a precaution to prevent overheating.

Your boiler has detected a faulty connection to a temperature sensor, which has caused it to shut down for safety reasons.

Your boiler has lost its connection to the heat sensor, preventing it from knowing how hot it is, so it has stopped working as a safety precaution.

Your boiler's computer has encountered an internal error and cannot operate correctly, so it has shut down as a precaution.

Your boiler's internal computer is experiencing a communication error, meaning it has safely shut down because it cannot correctly manage its own operations.

Your boiler's computer is having trouble communicating with its internal systems, which has caused it to shut down for safety reasons.

Your boiler's internal computer has detected a fault causing the internal fan to run continuously even when the boiler is not trying to heat your home.

Your boiler has attempted to light the flame but cannot detect that it has successfully ignited, so it has shut down as a safety precaution.

Your boiler has detected an internal software or communication error that is preventing it from operating safely.

Your boiler's computer system has encountered a critical processing error and needs to be restarted or reset by a professional.

Your boiler has detected that the electrical power supply is dipping below the level required for safe, stable operation, preventing it from firing up.

Your boiler's internal computer chip has identified that the plug-in electronic key is either missing, faulty, or doesn't match the specific model of your boiler.

Your boiler is struggling to keep its flame lit during start-up,, likely due to external weather conditions affecting the flue.

Your boiler is struggling to keep its flame lit because air or exhaust fumes are being blown back into the system, often due to high winds outside.

Your boiler has attempted to ignite several times but has failed to detect a flame, causing it to shut down for safety reasons.

Your boiler is repeatedly struggling to stay lit and has now shut itself down as a safety precaution while trying to ignite.

Your boiler is repeatedly failing to keep its internal flame lit, so it has safely shut itself down to prevent gas from building up.

Your boiler has detected an internal error while trying to confirm the flame is burning correctly, causing it to shut down for safety.

Your boiler has detected an internal error while trying to confirm it is burning fuel correctly, and it has shut down as a safety precaution.

Your boiler's electronic control system has encountered an internal communication error and has safely shut itself down to prevent further damage.

Your boiler's internal electronic control system has identified a technical failure that requires an expert to reset or replace the faulty circuit board.

Your boiler has stopped working because the mechanical fan responsible for venting combustion gases safely out of your home is not responding or receiving power.

Your boiler has stopped working because it cannot confirm that the internal fan, which is essential for safely exhausting gases, is running correctly.

Your boiler has stopped working because the mechanical fan responsible for venting combustion gases safely out of your home is not communicating with the control system.

Your boiler has stopped working because it cannot confirm that the internal fan, which is essential for safely venting combustion gases, is running correctly.

Your boiler has detected an issue with its internal temperature sensors, causing it to shut down for safety reasons so it can no longer provide heating or hot water.

Your boiler has stopped working because it is unable to accurately read the temperature of the water inside the unit.

Your boiler has detected that water is not circulating through it properly, likely due to a blockage or a pump issue, and has safely shut down to prevent damage.

Your boiler has detected that water is not flowing through its internal heating system quickly enough to operate safely.

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

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 is detecting that the water inside is heating up too quickly, which usually means the system is struggling to circulate heat properly.

Your boiler is overheating because water is not flowing through it properly, so it has shut down to protect itself from damage.

Your boiler has detected that water isn't flowing through its internal heating system as freely as it should, so it has shut down to prevent parts from overheating.

Your boiler has detected that water is heating up unevenly inside the unit, so it has safely shut down to prevent potential damage.

Your boiler has detected that water is escaping from your central heating system much faster than expected, which is preventing it from running properly.

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

Your boiler is struggling because the electricity coming into your home from the mains is weaker than the level required for it to operate safely.

Your boiler is having trouble 'talking' to its wireless thermostat or remote controller, which is preventing it from receiving instructions to turn on your heating or hot water.