BoilerFaultCodes.com

Johnson Starley Johnson & Starley Boiler Error Codes Fault Codes

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Most common fault codes

1
Your boiler is not firing up properly because it cannot establish a steady flame after several tries.
May be DIY safe · £120-350
2
Your boiler detects a flame when it shouldn't, so it has shut down safety to prevent a gas buildup.
Gas Safe engineer required · £120-280
3
Your boiler has automatically shut down because the water inside the system has become too hot.
May be DIY safe · £120-350

All 48 fault codes

Code Severity Plain English
1 High Your boiler is not firing up properly because it cannot establish a steady flame after several tries.
2 High Your boiler detects a flame when it shouldn't, so it has shut down safety to prevent a gas buildup.
3 High Your boiler has automatically shut down because the water inside the system has become too hot.
5 High Your boiler has stopped working because the internal computer cannot confirm that the fan is spinning at the correct speed to safely clear away exhaust fumes.
7 High Your boiler has shut down because the exhaust gases are getting too hot, which is a safety feature to prevent internal damage.
8 High Your boiler is struggling to detect the flame it needs to stay lit, which means it is shutting down for safety.
9 High Your boiler's internal computer is unable to communicate with the valve that controls the gas flow, usually due to a wiring or circuit board failure.
11 High Your boiler's temperature sensors are giving conflicting readings and cannot accurately tell how hot the water is.
12 High Your boiler has shut itself down for safety because it failed to light or detected a general system failure.
13 High Your boiler has tried and failed to light too many times, so it has locked itself out for safety.
21 High Your boiler's internal computer has encountered a communication error while reading its own electronic sensors.
25 High Your boiler's internal computer has encountered a memory processing error, causing it to shut down for safety.
26 High Your boiler is struggling to keep a flame lit and has safely shut down after several failed attempts to stay running.
30 High Your boiler has stopped working because its internal temperature sensor has developed an electrical fault and is no longer sending a correct reading to the control system.
31 High The boiler's internal thermometer that monitors water temperature for your radiators has developed a fault and is giving an incorrect reading.
32 Medium Your boiler is struggling to provide hot water because the internal thermometer responsible for measuring its temperature has developed an electrical fault.
33 Medium Your boiler is struggling to measure the temperature of your hot water, which usually means it cannot heat your taps properly.
34 High Your boiler is not receiving enough electrical power from the main supply to operate safely and has shut down as a precaution.
37 High Your boiler has detected that there is not enough water in the heating system to operate safely, causing it to shut down.
40 Emergency Your boiler has too much water in the system, causing the pressure to rise above a safe operating level.
41 High Your boiler has lost communication with the water pressure sensor, meaning it cannot confirm if there is enough water to run safely.
44 High Your boiler has detected a problem with the sensor that monitors the temperature of the water returning from your radiators.
45 High Your boiler has detected an electrical fault with the sensor that monitors exhaust gases, causing the system to shut down for safety.
46 High Your boiler has shut down because it can no longer safely monitor the temperature of the exhaust gases leaving the system.
47 High Your boiler has lost its connection to the sensor that monitors water pressure, meaning it can no longer tell if there is enough water to run safely.
99 High Your boiler's main control panel has lost connection with the internal computer, meaning they can no longer talk to each other to operate the heating.
E01 High Your boiler has tried to light several times but cannot establish a flame, causing the system to shut down for safety.
E02 High Your boiler has detected a flame when there shouldn't be one, so it has shut down for safety purposes.
E03 High Your boiler has switched itself off because it has reached a temperature that is too high and needs to cool down and be checked.
E05 High Your boiler has detected a problem with the fan that safely removes exhaust gases, and it has shut down for safety.
E08 High Your boiler is failing to detect the flame it has lit, causing the system to shut down for safety.
E09 High Your boiler has detected an issue with the internal gas valve's electronic signal, meaning it cannot safely control the fuel flow and has shut down as a precaution.
E12 High Your boiler's internal computer memory has encountered a critical error, causing the system to lock itself down for safety.
E15 High Your boiler has shut down because its internal temperature sensors are giving inconsistent readings and can no longer monitor the heat safely.
E16 High Your boiler has detected that one of its internal sensors is frozen or stuck at a specific reading, causing the system to shut down for safety.
E17 High Your boiler has detected that one of its internal sensors is frozen or stuck at a specific reading, causing the system to shut down for safety.
E18 High Your boiler has detected that one of its internal sensors is frozen or stuck at a specific reading, causing the system to shut down for safety.
E21 High Your boiler has detected an internal electronic signal failure and has shut down as a safety precaution.
E33 High Your boiler has detected a problem with the sensor that monitors the temperature of the water returning to the unit, causing it to stop running for safety.
E34 High Your boiler has shut down because the electricity supply reaching it is too low for it to operate safely.
E35 High Your boiler's temperature sensor is sending incorrect information to the control board, preventing the system from heating up safely.
F07 High Your boiler has detected an issue with the sensor that monitors the temperature of the exhaust fumes, causing it to shut down as a safety precaution.
F13 High Your boiler has shut down because too many reset attempts were made remotely or via the interface, and it now requires a manual reset or investigation to ensure it is safe to run.
F37 High Your boiler has detected that the water pressure in the system is too low to operate safely and has shut down to prevent damage.
F40 Emergency Your boiler has too much water inside its system, which can put unnecessary stress on the pipes and seals.
F47 High Your boiler has lost its connection to the sensor that monitors water pressure, meaning it cannot confirm there is enough water to run safely.
F52 High Your boiler is having trouble measuring the temperature of your hot water, which usually means your taps will only run cold.
F53 High Your boiler has shut down because a sensor has detected that the exhaust gases are getting too hot, which is a safety feature to prevent damage.

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