1-Eb Low

Worcester Bosch 1-Eb Fault Code

Also written as 1EB — same fault.

The Worcester Bosch 1-Eb fault code means: your boiler's internal computer components are having trouble communicating because their software versions do not match.. It appears on 3 Worcester Bosch models in our database.

Monitor it

This is a minor fault. Keep an eye on it and mention it at your next annual boiler service. Reset the boiler and see if it clears.

Technical description: Software version of the equipment electronics (ancillary version)

What causes the Worcester Bosch 1-Eb fault?

This fault occurs when the main control board and the display screen are running on different software versions that cannot talk to each other correctly. It most commonly happens after one of these parts has been replaced during a repair, or if a software update has failed to sync across both components. Essentially, the 'brain' and the 'face' of the boiler are speaking different languages.

Typical repair cost £0-120 (including labour)

DIY fix possible

Press the 'Reset' button on the front display panel and wait for the boiler to restart.Switch the boiler off at the main electrical spur, wait 30 seconds, and switch it back on.Check if any external smart controls or accessories have recently been updated or replaced.

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Worcester Bosch models that show the 1-Eb fault code

Click a model for the full fault code list and model-specific repair notes.

Source

Worcester Bosch 1-Eb fault code information on this page is sourced and cross-checked against the official Worcester Bosch service / installation manuals for each affected model.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026