24 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 |
|---|---|---|
| 47-116-34 | ACO 27 MFFI | 2004–2007 |
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 stopped working because it tried to light three times but failed to detect a flame.
Your boiler has stopped working because it has sensed that there is not enough water or water flow inside the heating system.
Your boiler has automatically shut down because the water inside it has become dangerously overheated.
Your boiler is struggling to stay lit and has failed to maintain a flame multiple times, causing it to lock itself out for safety.
Your boiler's internal mechanism for clearing waste gases is not working correctly, which forces the boiler to shut down for your safety.
Your boiler has detected an internal communication or electronic monitoring error and has safely shut down to prevent potential risks.
Your boiler has detected an internal electronic communication failure, meaning the safety systems cannot properly monitor its operation.
Your boiler's computer is experiencing a communication error or internal glitch, preventing it from operating reliably.
Your boiler has lost the signal from the sensor that monitors the temperature of your hot water, meaning it cannot safely heat the water for your taps.
Your boiler has lost the ability to measure your hot water temperature accurately, which means it will stop heating your taps and shower.
Your boiler has temporarily stopped working because it has lost the signal from the sensor that measures how hot the water is getting.
Your boiler has temporarily stopped working because a sensor that measures the temperature of the water leaving the boiler is sending an incorrect reading.
Your boiler has temporarily stopped working because it cannot properly read the temperature of the water returning from your radiators.
Your boiler has detected an internal temperature sensor issue, which has safely stopped the heating from working to prevent any damage.
Your boiler has temporarily stopped working because it has detected an issue with the sensor connected to your underfloor heating system.
Your boiler has detected that a flame is present even though it has commanded the gas supply to shut off, which indicates a serious safety monitoring fault.
Your boiler has lost connection to its outdoor temperature sensor, but it should still continue to keep your home warm using its backup settings.
Your boiler is receiving an incorrect temperature reading because of a wiring issue with the outside weather sensor, but your heating and hot water should usually still work normally.
Your boiler's internal extraction fan is running when it shouldn't be, which is a safety lockout to prevent the appliance from operating incorrectly.
Your boiler is trying to start its internal fan, but a safety switch is not detecting the airflow needed to let the ignition safely proceed.
Your boiler has lost communication with the wall-mounted room thermostat, meaning it cannot properly read your home's temperature.
Your boiler has detected an internal issue with its main electronic brain, causing it to safely shut down.
Your boiler has temporarily stopped working because it cannot accurately measure the temperature of the water flowing through it.
Your boiler's main computer control panel is experiencing a general communication error, causing the entire system to stop working.
BoilerFaultCodes