43 fault codes with plain-English explanations, severity ratings, DIY guidance, and repair cost estimates.
Replaced by: GENUS PREMIUM EVO SYSTEM
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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 |
|---|---|---|
| 41-116-22 | Clas HE 24 System | 2007–2013 |
| 41-116-23 | Clas HE System 30 | 2007–2013 |
| 41-116-26 | Clas HE 18 System | 2007–2013 |
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Your boiler has detected that it is running too hot and has automatically shut itself down to prevent damage.
Your boiler's water pressure sensor is failing to provide a signal, meaning the system cannot accurately measure how much water is inside, which prevents it from firing safely.
Your boiler is struggling to push water around your heating system because the flow is too slow or blocked.
Your boiler is struggling to move enough water through its system, which is often caused by low pressure or trapped air in the radiators.
Your boiler is struggling to push water around your heating system, usually because there is air trapped inside or the pressure is too low.
Your boiler is struggling to push water around your heating system, likely due to a blockage or a pump issue, which has caused it to stop heating.
Your boiler is struggling to pump water around your heating system correctly, which is likely due to low pressure or a blockage.
Your boiler has detected that the water pressure inside the system has dropped too low to operate safely.
Your boiler has lost the ability to measure the temperature of the water currently heating your radiators due to a broken or disconnected sensor connection.
Your boiler is unable to read the temperature of the water returning to it from your radiators, so it has stopped working as a safety precaution.
Your boiler is struggling to read the outdoor temperature, which means it cannot automatically adjust your heating to match the weather outside.
Your boiler is struggling to accurately measure the temperature of the water circulating through your heating system, so it has stopped working for safety reasons.
Your boiler is struggling to pump water around your heating system correctly, which is preventing it from heating your home properly.
Your boiler is struggling to move water around your heating system effectively, preventing it from heating your home properly.
Your boiler is struggling to move water around your heating system effectively, as if there is a blockage or too much air trapped inside.
Your boiler is struggling to read the temperature of the water in your separate storage tank because the sensor responsible for checking it has a loose connection or a faulty reading.
Your boiler is having trouble communicating with the solar panel sensor, meaning it cannot accurately monitor the temperature of your solar water heating system.
Your solar water heating system has become too hot and has automatically shut down to prevent damage to the equipment.
Your boiler has detected that the temperature inside the system is getting dangerously close to freezing and is running its built-in protection mode to prevent ice damage.
Your boiler's internal computer is experiencing a memory error, meaning it can no longer remember how to operate correctly.
Your boiler has lost the ability for its internal control brains to talk to one another, preventing it from starting up correctly.
Your boiler's central control computer is experiencing a communication fault and cannot operate the system safely.
Your boiler has been manually restarted too many times in a short period, so it has triggered a temporary lockout as a protective measure.
Your boiler's main control computer is experiencing an internal electronic fault and cannot safely manage the heating or hot water processes.
Your boiler's central control computer is experiencing a communication or processing error, which has caused it to shut down for safety reasons.
Your boiler's internal computer is experiencing a communication fault, which prevents the system from starting up or operating your heating and hot water.
Your boiler is struggling to read the room temperature because the connection to the thermostat or temperature sensor has been interrupted or damaged.
Your boiler has stopped working because it cannot light the internal flame needed to heat your water.
Your boiler has detected a flame when it should be turned off, which is a significant safety issue that requires immediate attention from a professional.
Your boiler is struggling to keep the flame lit correctly, causing it to detach from the burner, which prevents the unit from heating your home safely.
Your boiler has tried to start up but failed to light the flame, so it has temporarily locked itself out for safety.
Your boiler has tried and failed to light the gas flame twice, so it has stopped trying to prevent a buildup of gas.
Your boiler has detected that the flame inside has gone out during operation and it is struggling to stay lit.
Your boiler's fan, which is essential for safely venting exhaust gases, is struggling to reach the speed it needs to operate, causing the system to stop as a safety precaution.
Your boiler has detected an interrupted electrical connection in the safety circuit, which has caused it to shut down to prevent potential overheating.
Your boiler is struggling to accurately measure the temperature of the water being sent to your radiators, which may cause your heating system to work less efficiently or stop altogether.
Your boiler is struggling to accurately read the temperature of the water returning from your radiators, which means it cannot heat your home efficiently.
Your boiler is having trouble reading the temperature for one of its heating areas, which may cause that specific part of your home to be colder than it should be.
Your boiler is having trouble reading the temperature in one of the heating zones, which may stop that specific area of your home from heating up properly.
Your boiler is struggling to detect the flow of water correctly because a sensor that measures system pressure or circulation has stopped working properly.
Your boiler has detected that the water temperature in your heating system has risen higher than the safe limit set for your radiators.
Your boiler has detected that the water temperature in one of your heating zones is higher than it should be, causing the system to shut down to prevent damage.
Your boiler has detected that the external thermostat connected to your underfloor heating system has triggered a safety shut-off or is disconnected, meaning the heating will not run until this is resolved.
Not faults — these are normal operating states. Tap to expand.
BoilerFaultCodes