What does the Worcester Bosch EB error code mean?
EB means the burner was running and stopped before the system reached temperature — usually a flame-detection, gas-supply or overheat cause. It's related to EA but happens mid-operation, and needs an engineer.
What causes the Worcester Bosch EB fault?
The EB error on a Worcester Bosch boiler is most commonly triggered by:
- Interruption to the gas supply while running
- A failing flame-sensing electrode or contaminated electrode lead
- Blocked flue or flue-air problem affecting combustion
- Overheat safety trip from poor circulation or air in the system
How to fix the Worcester Bosch EB boiler fault
Follow these steps. If the code returns after you have completed them, stop and call a Gas Safe engineer.
- 1.Check other gas appliances still operate and the gas meter is on.
- 2.Reset the boiler once and observe; if EB recurs, don't keep retrying.
- 3.Book a Gas Safe engineer to inspect the flame electrode, flue and gas valve.
Frequently asked questions about the Worcester Bosch EB
What does EB mean on a Worcester Bosch boiler?
EB means the burner shut down during operation — the flame was lost while the boiler was running. It usually indicates a flame-sensing, gas-supply or flue issue.
What's the difference between EA and EB on a Worcester boiler?
EA is an ignition fault at start-up; EB is the boiler's flame lost mid-operation, after it had already lit. Both need a Gas Safe engineer but point to slightly different causes.