BoilerFaultCodes.com

Worcester Bosch Greenstar Si Combi / i System Fault Codes

CombiSystem Natural GasLPG 25-30 kW 2013-2022 Discontinued
GC Numbers: 47-311-9247-311-9341-311-8441-311-8541-311-8641-311-8741-311-8841-311-89

Replaced by: Greenstar 4000

The fault code is already on your display

Note it down before pressing reset — resetting clears the code immediately. How to read fault codes →

Most common fault codes

9A362
Your boiler’s internal computer chip is unrecognized or has been installed incorrectly, causing the system to stop working for safety reasons.
Gas Safe engineer required · £180-350
9U233
Your boiler's internal computer memory chip is having trouble communicating, which has caused the system to shut down for safety.
Gas Safe engineer required · £180-£350
A1281
Your boiler's internal pump is either jammed or struggling to move water because there is too much trapped air in the system.
May be DIY safe · £120-£350

All 28 fault codes

Code Severity Plain English
9A362 High Your boiler’s internal computer chip is unrecognized or has been installed incorrectly, causing the system to stop working for safety reasons.
9U233 High Your boiler's internal computer memory chip is having trouble communicating, which has caused the system to shut down for safety.
A1281 High Your boiler's internal pump is either jammed or struggling to move water because there is too much trapped air in the system.
B7257 High Your boiler's internal computer has encountered a critical communication error and cannot operate safely.
C1264 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.
C4273 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.
C6215 High Your boiler's fan is spinning faster than it should, which means the system has stopped running to prevent internal damage.
C7214 High Your boiler has stopped working because the internal fan, which safely exhausts fumes, is not spinning or starting up.
D1240 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.
D4271 High Your boiler is overheating because water is not moving through the system quickly enough to carry heat away.
E2222 High Your boiler has detected an electrical fault with the internal sensor that monitors water temperature, causing the system to shut down for safety.
E5218 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.
E9219 High Your boiler has sensed that it is getting too hot and has shut down as a safety precaution to prevent damage.
E9224 High Your boiler has shut down because a safety sensor detected that the internal exhaust gases have reached a dangerously high temperature.
EA227 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.
EF349 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.
F0237 High Your boiler's computer has experienced a system failure and has entered a safety mode to prevent damage.
F7228 High Your boiler thinks it sees a flame when there shouldn't be one, causing it to shut down for safety purposes.
FA306 High Your boiler thinks it can still see a fire inside even though it has commanded the burner to turn off.
FA364 Emergency Your boiler has detected a potential internal gas leak during its safety checks and has shut down to keep your home safe.
FB365 Emergency Your boiler has detected a potential internal gas leak during its safety checks and has shut down to keep your home safe.
FD231 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.

Worcester Bosch Greenstar Si Combi / i System is discontinued — time for a new one?

Parts for discontinued models can be hard to find and expensive. A new A-rated boiler could save you money on both repairs and energy bills.

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