30 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 |
|---|---|---|
| 41-044-64 | ecoTEC plus 630 VU GB 306/5-5 | 2012–2015 |
| 41-044-83 | ecoTEC plus 630 H system A VU GB 306/5-5 A | 2015–2017 |
| 41-694-25 | ecoTEC plus 630 VU 306/5-5 (H-GB) R6 | 2017–present |
| 41-694-26 | ecoTEC plus 630 VU 306/5-5 (P-GB) R6 | 2017–present |
| 41-694-49 | ecoTEC plus 630 VU 30CS/1-5 (N-GB) | 2023–present |
| 47-044-67 | ecoTEC plus 630 VU GB 306/5-5 | 2005–2015 |
| 41-044-84 | ecoTEC plus 630 LPG system A VU GB 306/5-5 A R4 | 2015–2017 |
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Your boiler's control panel and its internal computer are not talking to each other, meaning the unit cannot receive instructions to provide heat or hot water.
Your boiler has stopped working because it cannot accurately measure the temperature of the water leaving the unit due to a sensor or wiring connection fault.
Your boiler has stopped working because it cannot accurately measure the temperature of the water returning to the unit due to a faulty sensor or wiring.
Your boiler has detected an electrical fault with the internal sensor that monitors the water temperature leaving the unit, causing it to shut down for safety.
Your boiler has stopped working because it thinks the water returning to the unit is much hotter than it actually is, causing it to shut down for safety.
Your boiler has detected an electrical fault with the sensor that monitors your hot water tank, meaning it cannot accurately tell if your water is hot enough.
Your boiler has switched itself off because it has reached an unsafe temperature and needs to cool down.
Your boiler has stopped working because the water pressure inside the system has dropped too low to operate safely.
Your boiler has shut down because there is a significant difference between the water temperature leaving the boiler and the temperature returning to it, usually caused by a circulation problem.
Your boiler has shut down because the internal water temperature is heating up much faster than it can be circulated away, usually meaning the water is stuck or the pump is struggling.
Your boiler has sensed a flame when there shouldn't be one, so it has shut down as a safety precaution to prevent damage.
Your boiler is trying to light itself to provide heat, but it is failing to create a flame, likely because it is not getting enough gas or the spark isn't catching.
Your boiler was working but the flame went out and it cannot manage to light itself back up.
Your boiler's fan is unable to spin at the correct speed, which prevents the boiler from safely clearing exhaust fumes and starting the ignition process.
Your boiler has lost its ability to communicate with its external controls, such as your thermostat, due to an electrical glitch in the internal data wiring.
Your boiler is unable to correctly control the flow of gas, causing it to shut down for safety purposes.
Your boiler has detected that the gas valve is not closing as quickly as it should, preventing the unit from shutting down the burner safely.
Your boiler's internal computer brain is having trouble reading its memory, causing the system to stop working for safety.
Your boiler has detected an internal communication error between its electrical sensors and the main control board, causing it to shut down for safety.
Your boiler's internal control board has become too hot and has shut down the system to prevent damage.
Your boiler's electronic control board has detected a confusing signal from the flame sensor, causing the system to shut down for safety.
Your boiler’s control board has lost its identity settings, meaning the internal computer no longer knows which specific model it is supposed to be operating.
Your boiler is struggling to accurately measure the water temperature leaving the unit, usually because a sensor has failed or become disconnected.
Your boiler has detected that the sensors measuring water temperature going in and out are giving conflicting readings, so it has shut down as a safety precaution.
Your boiler is unable to sense water moving or pressure building when it tries to start up, which has caused it to shut down for safety.
Your boiler's safety sensor has detected that the main heating component is getting too hot, so the system has shut itself down to prevent damage.
Your boiler is struggling to push waste gases out through the flue or is unable to clear internal condensation water properly.
Your boiler is having trouble communicating with an external hot water control component, meaning it doesn't know the temperature of the water heading to your taps.
Your boiler has stopped working because the water pressure is too low for it to operate safely.
Your boiler's computer brains are not talking to each other correctly because a security code needs to be re-entered after a repair.
Not faults — these are normal operating states. Tap to expand.
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BoilerFaultCodes