BoilerFaultCodes 2.4
Your boiler is currently taking a mandatory rest period to prevent the system from overheating, which is a normal safety feature after it has been running for a while.
Worcester Bosch Greenstar R29 40 HE Fault codes & diagnostics
17 fault codes with plain-English explanations, severity ratings, DIY guidance, and repair cost estimates.
Regular Natural Gas 40 kW 2003-2006 Discontinued
GC Numbers 41-311-6041-311-61
Download the Worcester Bosch Greenstar R29 40 HE manual
PDF
Versions & GC numbers
The fault code is already on your display
Note it down before pressing reset — resetting clears the code immediately. How to read fault codes →
Severity at a glance
Each cell = one fault code. Hover to identify. 2 Emergency
9 High
5 Low
1 Unrated
Which version do you have?
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 |
|---|---|---|
| 41-311-60 | Greenstar R 29 HE Conventional | 2003–2006 |
| 41-311-61 | Greenstar R 40 HE Conventional | 2003–2006 |
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.
Just want the most common Worcester Bosch Greenstar R29 40 HE faults?
The top 6 problems in plain English — with causes, DIY checks and repair costs.
Fault codes
All 17 documented codes
Tap any card for details
5.2 Your boiler is failing to light the flame, which means your heating and hot water have stopped working.
Your boiler is failing to light the flame, which means your heating and hot water have stopped working.
Parts commonly replaced
- Ignition electrode
- Ignition lead
- Gas valve
- Printed Circuit Board (PCB)
Related codes
9.3 Your boiler's electronic control system responsible for safely lighting the gas flame has developed a fault and cannot start the heating process.
Your boiler's electronic control system responsible for safely lighting the gas flame has developed a fault and cannot start the heating process.
Parts commonly replaced
- Printed Circuit Board (PCB)
- Wiring harness
Related codes
b1 Your boiler has lost its connection to an internal system component, meaning it cannot properly communicate with its own controls to function.
Your boiler has lost its connection to an internal system component, meaning it cannot properly communicate with its own controls to function.
Parts commonly replaced
- Keyed plug / Coding plug
- PCB
Related codes
C1 Your boiler is struggling to push air through its internal system, which prevents it from safely igniting and providing heating or hot water.
Your boiler is struggling to push air through its internal system, which prevents it from safely igniting and providing heating or hot water.
Parts commonly replaced
- Fan assembly
- Printed Circuit Board (PCB)
- Flue sensor
Related codes
d3 Your boiler is failing to start because it is not receiving a signal from your thermostat or internal control link to turn on the heating.
Your boiler is failing to start because it is not receiving a signal from your thermostat or internal control link to turn on the heating.
Parts commonly replaced
- External controls/thermostat
- Wiring harness
- PCB
Related codes
E2 Your boiler's internal thermometer is not sending a signal, so the system is shutting down to prevent overheating because it doesn't know how hot the water is.
Your boiler's internal thermometer is not sending a signal, so the system is shutting down to prevent overheating because it doesn't know how hot the water is.
Parts commonly replaced
- NTC Flow Temperature Sensor
- Wiring harness / Sensor connector
Related codes
E9 Your boiler has detected that it is getting too hot and has automatically shut itself down to prevent any damage or safety issues.
Your boiler has detected that it is getting too hot and has automatically shut itself down to prevent any damage or safety issues.
Parts commonly replaced
- NTC temperature sensor
- Central heating pump
- Heat exchanger
Related codes
EA Your boiler is trying to start but the flame is failing to light or stay on, so it has shut down as a safety precaution.
Your boiler is trying to start but the flame is failing to light or stay on, so it has shut down as a safety precaution.
Parts commonly replaced
- Ignition electrode
- Gas valve
- Condensate trap
- Printed Circuit Board
Related codes
F0 Your boiler's computer system has encountered a critical internal error and can no longer safely control your heating or hot water.
Your boiler's computer system has encountered a critical internal error and can no longer safely control your heating or hot water.
Parts commonly replaced
- Printed Circuit Board (PCB)
- Wiring harness
Related codes
F7 Your boiler has detected that the internal flame is still burning even though it should have turned off, which is a significant safety precaution.
Your boiler has detected that the internal flame is still burning even though it should have turned off, which is a significant safety precaution.
Parts commonly replaced
- Gas valve
- Printed Circuit Board (PCB)
Related codes
FA Your boiler has detected that a flame is still burning even though it has tried to turn the gas supply off, which is a safety concern.
Your boiler has detected that a flame is still burning even though it has tried to turn the gas supply off, which is a safety concern.
Parts commonly replaced
- Gas valve
- Printed Circuit Board (PCB)
- Ionisation electrode
Related codes
Fd Your boiler is simply indicating that the reset button has been pressed briefly during normal operation, rather than it being a sign of a broken part.
Your boiler is simply indicating that the reset button has been pressed briefly during normal operation, rather than it being a sign of a broken part.
What to check first
- Wait for the boiler to return to its normal display mode automatically
- If the boiler does not resume, switch it off at the fused spur
- Wait 30 seconds and switch the power back on to clear the notification
P1
Your boiler is currently performing an automatic internal check or scheduled system routine and is temporarily unavailable for normal operation.
P1, P2, P3, P1...
Please wait, initialisation in progress.
P2 Your boiler is currently performing a brief startup check to ensure all internal systems are communicating correctly before it begins normal operation.
Your boiler is currently performing a brief startup check to ensure all internal systems are communicating correctly before it begins normal operation.
Related codes
P3
Your boiler is currently performing an automated internal calibration or maintenance check and will resume normal operation once finished.
Status & diagnostic codes 5 operating states & engineer diagnostics
Not faults — these are normal operating states. Tap to expand.
5 operating states & engineer diagnostics
Not faults — these are normal operating states. Tap to expand.
2.0 Status Your boiler is operating normally and there is no fault present. 2.5 Diagnostic Your boiler has shut down because it is getting too hot and cannot circulate the heat through your radiators effectively. 2.6 Diagnostic Your boiler is struggling to maintain a consistent temperature because the difference between the actual water temperature and the target temperature is outside of the expected range. 3.3 Diagnostic Your boiler is struggling to detect the flame needed to heat your home, so it has safely shut itself down to prevent any gas build-up. 5.0 Diagnostic Your boiler is currently running at its maximum heating capacity and is effectively notifying you that it is working hard to meet a high demand for warmth.