15 fault codes with plain-English explanations, severity ratings, DIY guidance, and repair cost estimates.
Replaced by: Greenstar 24i
This boiler uses LED flash patterns
Count the flashes in one repeating group before the pause. That number is your fault code. Do not reset until you have noted it. How to read fault codes →
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Your boiler has detected an internal communication or airflow issue that has caused it to shut down for safety.
Your boiler has been left in a service mode used for testing, meaning it is currently stuck running at a constant power level instead of operating normally.
Your boiler has stopped working because it has failed to light or has detected a dangerous build-up of heat.
Your boiler has detected an issue with the sensor that manages your hot water, meaning you will likely only have heating or very inconsistent water temperatures.
Your boiler is failing to clear combustion fumes properly and has automatically shut down to keep your home safe.
Your boiler has stopped working because one of its internal electrical safety fuses has blown, preventing the system from powering up.
Your boiler has lost electrical power to its internal control board due to a blown safety fuse, meaning it cannot operate until the circuit is restored.
Your boiler has stopped working because it failed to light the flame, which means your heating and hot water have turned off for safety.
Your boiler is failing to light the flame, which means it has stopped working to keep you safe.
Your boiler has stopped working because it failed to successfully light its internal flame.
Your boiler is providing hot water normally, but is not receiving the signal to turn on the central heating due to a control or wiring issue.
Your boiler is providing central heating but is failing to detect when you turn on a hot tap, meaning you have no hot water.
Your boiler has detected that it is getting too hot and has automatically shut itself down to prevent damage.
Your boiler is struggling to reach the temperature you have set because it is not receiving enough gas or is failing to detect the water flow correctly.
Your boiler has sensed that the water inside it is getting dangerously hot and has shut itself down to prevent damage.
BoilerFaultCodes