105 fault codes with plain-English explanations, severity ratings, DIY guidance, and repair cost estimates.
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The GC number on your boiler's data badge identifies the exact appliance and production years, as recorded in the UK Product Characteristics Database.
| GC number | Appliance (register name) | Produced |
|---|---|---|
| 41-819-52 | VITODENS 100-W Heat Only B1GA-11 | 2021–present |
| 41-819-53 | VITODENS 100-W Heat Only B1GA-16 | 2021–present |
| 41-819-54 | VITODENS 100-W Heat Only B1GA-19 | 2021–present |
| 41-819-55 | VITODENS 100-W Heat Only B1GA-25 | 2021–present |
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Your boiler is unable to read the temperature of your hot water cylinder, meaning your hot water may not heat up correctly to the set temperature.
Your boiler has detected a problem with the sensor that monitors the temperature of your hot water cylinder, meaning it cannot safely tell how hot your water is.
Your boiler has lost its connection to the outdoor weather sensor, which means it may not know how hard it needs to work to heat your home efficiently.
Your boiler is having trouble communicating with the outdoor sensor that detects the weather, which may affect how efficiently it heats your home.
Your boiler has shut down because it can no longer safely monitor the temperature of the exhaust gases leaving the system.
Your boiler has detected a technical fault with the sensor that monitors internal exhaust temperatures, causing the system to shut down for safety.
Your boiler has lost communication with its room thermostat or temperature sensor, meaning it cannot tell how warm your house is.
Your boiler is struggling to understand the current temperature of the room, which may prevent your heating from turning on or off correctly.
Your boiler has stopped working because the electrical voltage being supplied to it is too low to run the unit safely.
Your boiler has shut down because it has detected an unsafe build-up of heat or a lack of water flow, triggering a safety cut-out to prevent damage.
Your boiler has automatically shut down because the exhaust gases have reached a temperature that is too high, which is a safety feature to prevent damage or dangerous operation.
Your boiler has failed to detect a steady flame during operation, which has caused it to shut down for safety purposes.
Your boiler detects a flame when there shouldn't be one, so it has shut down as a safety precaution to prevent an uncontrolled fire.
Your boiler is having trouble detecting the flame used to heat your water, which is causing it to shut down for safety.
Your boiler's main internal computer has developed a communication error or hardware fault, preventing the system from operating safely.
Your boiler has stopped working because the fan that removes waste gases is spinning too slowly or is stuck.
Your boiler's internal computer brain is having trouble communicating with its electronic components, causing the system to stop working.
Your boiler has stopped working because the water pressure in the system has dropped too low to operate safely.
Your boiler's computer memory has encountered a reading error, preventing the system from running safely.
Your boiler has stopped working because the internal pump that moves hot water around your heating system is stuck or blocked.
Your boiler's internal computer system is having trouble communicating with its electronic connection module, preventing the unit from operating correctly.
Your boiler's internal computer parts are struggling to talk to each other, which prevents the system from running safely.
Your boiler has lost communication with your smart thermostat or heating controller and cannot receive instructions to heat your home.
Your boiler has detected an electrical communication problem between its internal components, meaning it cannot send or receive signals correctly to operate.
Your boiler's internal computer brain is having trouble talking to its control screen, meaning the system cannot process your commands or run correctly.
Your boiler has received an 'alert' signal from an external device, such as a smart thermostat or a pump, telling it to stop running.
Your boiler's internal components are struggling to talk to each other, which has caused the system to stop working for safety.
Your boiler's internal computer brains have lost the ability to talk to each other, meaning the system cannot operate for safety reasons.
Your boiler's computer memory has encountered a communication error and can no longer process its operating settings.
Your boiler's main internal computer has encountered a memory processing error and cannot communicate with the control board correctly.
Your boiler has detected a fault with the sensor that monitors the temperature of the water leaving the unit, meaning it cannot safely manage your heating or hot water.
The boiler has detected a faulty internal wiring connection or a broken sensor that monitors the temperature of the water leaving the unit, which prevents it from heating correctly.
Your boiler has detected an electrical fault or overheating issue within its internal sensors and has shut down to protect itself.
The boiler has detected a faulty connection or damaged wiring to a safety sensor, causing it to stop running for your protection.
The boiler has automatically shut down because it became too hot, but it will attempt to restart itself once it has cooled down.
Your boiler has failed to correctly sense its own flame during a startup check, which means it has shut down for safety purposes.
Your boiler has identified a problem with the internal valve that controls the gas flow, which has caused the system to shut down for safety.
Your boiler has stopped working because it cannot properly measure the amount of air flowing through the system to safely burn gas.
Your boiler is having trouble detecting the flame needed to heat your water, so it has shut down as a safety precaution.
Your boiler is failing to detect a steady flame, meaning it cannot stay lit to provide heating or hot water.
Your boiler has shut down because it detected dangerously high levels of carbon monoxide during the combustion process.
Your boiler is not receiving enough gas to run at full power, so it has automatically lowered its performance to stay operational.
Your boiler has detected a technical issue with the internal gas control valve that regulates the fuel supply, causing the system to lock out for safety.
Your boiler has detected an unusual reading from the flame detection system while trying to start, preventing the burner from igniting safely.
Your boiler is not receiving enough gas to light properly, which means it cannot provide heating or hot water.
Your boiler is unable to start the flame needed to heat your water and home.
Your boiler is trying to start but cannot detect a flame, which prevents it from firing up to provide heating or hot water.
Your boiler's internal control board has detected a critical electrical failure where a safety switch for the gas supply has stuck in the open position.
Your boiler has detected an internal electrical safety issue where the gas valve remains powered when it should be shut off.
Your boiler has detected an electrical fault with the gas valve that prevents it from shutting off correctly, which is a safety concern.
Your boiler is starting to ignite but the flame is going out almost immediately, preventing the system from staying on.
Your boiler has detected a safety issue where the gas supply is failing to shut off correctly, causing the system to lock out for your protection.
Your boiler is struggling to keep the flame lit during its automated setup process, meaning it cannot safely run to provide you with heating or hot water.
Your boiler has detected that it is not moving heat efficiently during its internal safety check, causing it to shut down to prevent overheating.
Your boiler's burner is having trouble automatically adjusting itself to ensure the gas is burning safely and efficiently.
Your boiler is attempting to light but is failing to keep the flame burning steadily, causing it to shut down for safety.
Your boiler is attempting to start but cannot detect the flame required to produce heat, causing it to shut down for safety.
Your boiler is failing to stay lit because it cannot reliably detect the flame, so it is shutting down for your safety.
Your boiler has stopped because the flame inside went out while it was trying to heat your water or home.
Your boiler has repeatedly failed to ignite and has now locked itself down for safety to prevent further issues.
Your boiler has detected an internal electrical fault within its main control board which is preventing it from safely lighting the burner.
Your boiler has detected a critical internal failure within its main control computer, preventing it from starting safely.
Your boiler has detected an internal electrical safety issue and has shut down to prevent damage or potential danger.
Your boiler's central control computer has encountered an internal error and has shut itself down as a safety precaution.
Your boiler has detected an internal electrical fault that is preventing it from lighting the burner safely.
Your boiler's main internal control computer has developed a serious hardware fault and is unable to manage the heating process safely.
Your boiler has detected an electrical fault within its main control sensor or the internal circuit board, preventing it from firing up safely.
Your boiler's main control unit has developed an internal electrical fault, meaning the computer that manages the heating system is no longer working correctly.
Your boiler has detected an electrical grounding issue with its internal flame monitoring system, which has caused it to shut down for safety.
Your boiler's main internal computer has developed a serious electronic fault and can no longer control the heating properly.
Your boiler has detected an electrical issue with the internal flame sensor or its main control board, preventing it from heating your home safely.
Your boiler's main control computer has developed a serious internal error and can no longer manage the heating process safely.
Your boiler has detected an internal electrical problem with the sensors that monitor the flame, causing the system to shut down for safety.
Your boiler's main control computer has developed an internal electrical fault and can no longer manage the heating process safely.
Your boiler's main control computer has developed an internal electronic fault and can no longer manage the heating process.
The boiler's main internal computer has developed a serious communication or hardware fault, preventing the unit from operating at all.
Your boiler has shut down because it thinks a safety sensor in the flue pipe is not fitted correctly, preventing the system from monitoring exhaust gases safely.
Your boiler's main control computer has developed an internal electrical fault and is unable to manage the heating process.
Your boiler's main control computer has developed an internal electrical fault and is unable to manage the heating process.
Your boiler is having trouble connecting to the internet to set its internal clock, which may disrupt your heating schedules.
Your boiler has detected a conflicting reading between its internal temperature sensors and has shut down as a safety precaution to prevent overheating.
Your boiler is having trouble controlling the flame correctly, causing it to shut down for safety.
Your boiler is struggling to correctly detect that the flame has ignited, causing it to shut down for safety purposes.
Your boiler's computer system has encountered an internal software timing error that is preventing it from running its startup sequence correctly.
Your boiler's computer has encountered an internal error while trying to process its operating software, causing the system to stop working.
Your boiler's internal computer system has encountered a processing error and cannot follow its normal startup or operating sequence.
Your boiler's internal computer has encountered a software timing error, causing it to stop running for safety.
Your boiler has detected a communication error between its internal controls and the burner, meaning it has safely shut down to prevent incorrect operation.
Your boiler's computer has detected an internal configuration error that is preventing the burner from starting, meaning you currently have no heating or hot water.
The boiler's internal computer has crashed or encountered a software glitch that is preventing it from managing its functions safely.
Your boiler's fan, which safely clears exhaust gases, is struggling to spin correctly or is stuck, causing the system to shut down for safety.
The fan that helps your boiler run safely is having trouble spinning or is stuck, which has caused your heating to stop working for safety reasons.
Your boiler is pulling its own exhaust fumes back into the air intake, which prevents the burner from operating safely and efficiently.
Your boiler is struggling to detect a stable flame because the internal sensor signal is too weak during its setup phase.
Your boiler is struggling to get enough gas to operate properly when it tries to tune itself for efficient burning.
Your boiler's internal self-tuning system is detecting an unusual flame signal, which is preventing it from completing its safety checks and starting up correctly.
Your boiler's internal sensor for measuring water pressure has lost electrical contact or is faulty, causing the system to stop working until it can safely read the pressure level again.
Your boiler's internal computer has encountered a software timing error or a communication glitch while trying to run its pre-set operation sequence.
Your boiler has lost communication with its smart controls or internal sensors, meaning it cannot receive the correct instructions to operate.
Your boiler's internal computer has been set up with the wrong configuration settings and does not know how to operate correctly.
Your boiler's computer system has been configured with the wrong internal settings and cannot operate correctly because it doesn't recognize which model it is supposed to be.
Your boiler has detected that waste water (condensate) is not draining away correctly, which is causing the burner to shut down to prevent damage.
Your boiler has lost the signal from a sensor for a secondary heating zone, so it has safely shut off that specific part of your home's heating to prevent overheating.
Your boiler has detected a faulty connection in a temperature sensor for a secondary heating zone, so it has stopped that zone from heating to prevent potential damage.
Your boiler is connected to a smart heating control that hasn't been set up correctly in the system settings yet, so it is just waiting for the right instructions.
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BoilerFaultCodes