BoilerFaultCodes.com

Worcester Bosch Greenstar Si Combi / i System Fault Codes

CombiSystem Natural GasLPG 25-30 kW 2013-2022 Discontinued

Replaced by: Greenstar 4000

All 30 fault codes

Code Severity Plain English
9A 362 High Your boiler’s internal computer chip is unrecognized or has been installed incorrectly, causing the system to stop working for safety reasons.
9U 233 High Your boiler's internal computer memory chip is having trouble communicating, which has caused the system to shut down for safety.
A1 281 High Your boiler's internal pump is either jammed or struggling to move water because there is too much trapped air in the system.
B7 257 High Your boiler's internal computer has encountered a critical communication error and cannot operate safely.
C1 264 High Your boiler has switched itself off because it detected that the internal fan stopped moving the air needed for safe combustion around while it was running.
C4 273 High Your boiler has detected that the fan was running or air was moving when it shouldn't have been, causing the system to lock out for safety.
C6 215 High Your boiler's fan is spinning faster than it should, which means the system has stopped running to prevent internal damage.
C7 214 High Your boiler has stopped working because the internal fan, which safely exhausts fumes, is not spinning or starting up.
D1 240 High Your boiler has detected a fault with the sensor that monitors the temperature of the water returning to the unit, causing it to stop the heating system for safety.
D1 240 High Your boiler has stopped working because its internal temperature sensor has developed an electrical fault and can no longer monitor the water returning to the unit.
D4 271 High Your boiler is overheating because water is not moving through the system quickly enough to carry heat away.
E2 222 High Your boiler has detected an electrical fault with the internal sensor that monitors water temperature, causing the system to shut down for safety.
E5 218 High Your boiler has shut down because the internal water temperature has become too hot, likely due to a lack of water flow or a circulation problem.
E9 219 High Your boiler has sensed that it is getting too hot and has shut down as a safety precaution to prevent damage.
E9 224 High Your boiler has shut down because a safety sensor detected that the internal exhaust gases have reached a dangerously high temperature.
EA 227 High Your boiler is failing to light the gas burner or is losing the flame while it is running, meaning you will have no heating or hot water.
EA 227 High Your boiler is failing to stay alight because it cannot detect a flame, which means your heating and hot water will not work.
EF 349 Medium Your boiler is overheating because water isn't moving through the system quickly enough, forcing it to run at its lowest power to prevent damage.
F0 237 High Your boiler's computer has experienced a system failure and has entered a safety mode to prevent damage.
F7 228 High Your boiler thinks it sees a flame when there shouldn't be one, causing it to shut down for safety purposes.
FA 306 High Your boiler thinks it can still see a fire inside even though it has commanded the burner to turn off.
FA 364 Emergency Your boiler has detected a potential internal gas leak during its safety checks and has shut down to keep your home safe.
FB 365 Emergency Your boiler has detected a potential internal gas leak during its safety checks and has shut down to keep your home safe.
FD 231 High Your boiler has lost its connection to the main electrical supply or has detected a significant power interruption.
NO CODE 212 High Your boiler is shutting down because it is heating up much faster than it should, usually due to water not flowing through the system properly.
T1 Low Your boiler is currently running a self-diagnostic check to ensure the ignition system is sparking correctly before it starts up.
T2 High Your boiler is failing a self-test of its internal fan, which is preventing the system from starting up safely.
T3 Low Your boiler is performing a routine check of its internal pump and may temporarily pause normal operation while it completes the test.
T4 High Your boiler is struggling to switch between providing heating and hot water because of an internal valve check failure.
T6 High Your boiler has detected an internal safety electronic error and has stopped working to prevent a malfunction.

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