11 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 |
|---|---|---|
| 41-094-27 | Synergy 29 | 2003–2010 |
Appliance names and production years are taken from the UK Product Characteristics Database (the SAP/SEDBUK register). Where a GC number is also printed in this model's own manufacturer manual, both sources were checked to agree.
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Your boiler has failed to ignite because it is not receiving gas or has detected an issue with the internal airflow, meaning you currently have no heating or hot water.
Your boiler is failing to circulate water properly because it cannot sense the flow it needs to heat your home.
Your boiler is struggling to clear air and gases away properly because the exhaust pipe or an internal sensor is blocked with debris.
Your boiler has stopped working because the water pressure inside the system has dropped too low.
Your boiler is struggling to talk to your room thermostat or remote control unit, which is preventing it from knowing when to turn the heating on.
Your boiler has detected an internal configuration error with its main electronic brain, which prevents it from operating safely.
Your boiler has stopped working because it is unable to accurately measure the temperature of the water inside the unit.
Your boiler has detected that it is running too hot and has automatically shut down to prevent damage to its internal components.
Your boiler's internal computer has developed an error and can no longer control the heating system correctly.
Your boiler is unable to properly drain away the water it creates during normal operation, which is stopping it from running safely.
Your boiler is struggling to detect that it is safely draining away the water created during its operation, causing it to stop working to prevent internal damage.
BoilerFaultCodes