EA 227
No flame detected — ignition failure
Check gas supply and flame sense electrode; often a gas valve, electrode or PCB fault requiring an engineer.
Fault code index
Worcester Bosch Boiler Fault Codes Explained
Every common Worcester Bosch lockout code, what it actually means, and whether it is a simple pressure top-up or a safety fault needing a Gas Safe registered engineer.
Worcester Bosch diagnostic code matrix
C6
Fan speed out of range
Fan bearing or Hall sensor failure. The boiler locks out for safety; the fan assembly usually needs replacing.
E9
Overheat / primary thermostat
Usually poor circulation from a seized pump, blocked heat exchanger or sludge. Needs diagnosis, not a reset.
F0
Internal PCB fault
Sensor wiring or control board failure — engineer diagnosis required.
1017 B
Low system pressure
Top up via the filling loop to 1.0–1.5 bar. Repeated loss means a leak or failed expansion vessel.
D1 286
Return temperature above flow
Reversed pipework or a faulty sensor; commonly seen after a component swap.
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Worcester Bosch fault codes — FAQs
What does EA 227 mean on a Worcester Bosch boiler?
- EA 227 indicates no flame detected — ignition failure. It should be diagnosed by a Gas Safe registered engineer if it returns after a single reset.
Can I clear a Worcester Bosch fault code myself?
- Low pressure codes can usually be cleared by repressurising the system. Ignition, fan, flame and overheat codes need an engineer.
Do you carry Worcester Bosch parts?
- We stock common Worcester Bosch fans, pumps, sensors and electrodes, so many repairs are completed on the first visit.
Will a repair affect my Worcester Bosch warranty?
- No. We fit genuine manufacturer-approved parts and record the work, keeping your warranty intact.
How fast can you attend a Worcester Bosch breakdown in Warrington?
- Same-day or next-morning in most cases — we cover Warrington and the surrounding areas every day.
Worcester Bosch boiler locked out? We can help today.
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