27 fault codes with plain-English explanations, severity ratings, DIY guidance, and repair cost estimates.
Replaced by: Greenstar 25/30i
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Your boiler is struggling to transfer heat to your hot water because a key internal component is likely blocked or damaged.
Your boiler has detected a serious problem with the fan that safely removes exhaust gases, meaning the system has shut down for your safety.
Your boiler has detected a fault with the burner unit, meaning it cannot safely ignite or maintain a flame to provide heat or hot water.
Your boiler has detected a serious internal problem with the gas burner system, causing it to shut down for safety.
Your boiler's main control computer has developed an internal electrical fault and can no longer safely operate the system.
Your boiler has detected a problem with how it moves air and exhaust gases, which has caused it to shut down for safety.
Your boiler's burner has encountered a serious ignition or combustion failure, meaning it cannot safely light to provide heat or hot water.
Your boiler has detected a critical internal fault with the burner system that regulates the fuel supply, meaning the appliance cannot ignite safely.
Your boiler has detected an issue with the internal burner assembly components, likely related to the incorrect gas injection setup for your fuel type.
Your boiler has lost water pressure, and the internal component used to refill it is likely disconnected or faulty.
Your boiler has detected a failure with the internal gas control valve, meaning it cannot safely ignite to provide heating or hot water.
Your boiler has detected a specific internal electronic fault with the valve that controls the gas supply, meaning the appliance cannot ignite safely and will remain shut down.
Your boiler has detected an internal issue with the component meant to release trapped air from the system, which may prevent it from heating properly.
Your boiler has failed to detect a flame and has safely shut down to prevent unburned gas from building up.
Your boiler appears to have lost all electrical power, meaning it cannot start up or provide any heating or hot water.
Your boiler has lost power or has a serious internal electronic failure, meaning it cannot start the ignition process to provide heating or hot water.
Your boiler has lost power or has a major electrical fault, meaning it cannot provide any heating or hot water despite the fuse board appearing normal.
Your boiler is not reacting when you turn on the heating because it isn't receiving the correct signal to start that specific mode.
Your boiler is not detecting that you have turned on a hot water tap, so it isn't starting the burner to heat the water.
Your boiler is trying to run the heating even though you have turned the control knob to the off position, which usually indicates an internal electronic fault or a stuck component.
Your boiler has shut down because it has detected its internal temperature is too hot and is now in a safety lockout.
Your boiler has failed to light the flame or detects that the flame has gone out, causing the system to shut down for safety.
Your boiler is not starting because it cannot successfully ignite the gas flame to heat your water.
Your boiler has detected a problem with one of its internal temperature sensors and has stopped working as a safety precaution.
Your boiler has detected an internal communication problem with its sensors or electrical wiring, causing it to stop operating to ensure your safety.
Your boiler has failed to ignite properly, meaning it cannot create the flame needed to provide you with heat or hot water.
Your boiler has encountered a general electrical failure, likely caused by moisture or damage to the internal brain of the unit.
BoilerFaultCodes