BoilerFaultCodesWorcester Bosch 2927 B Fault Code
Also written as 2927B — same fault.
The Worcester Bosch 2927 B fault code means: your boiler has lost its flame while running and has shut down for safety because it can no longer detect the fire needed to heat your water.. It appears on 10 Worcester Bosch models in our database.
Technical description: Flame failed during burner operation. Open the main shut off valve, shut down the appliance and check gas line, replace the ionisation electrode, set burner correctly and minimum rated load, check the integrity flue system and if the interconnected room air supply is too small, or the size of the ventilation opening is too small, clean the heating block on the flue gas side or replace the control unit/burner control unit
What causes the Worcester Bosch 2927 B fault?
This fault occurs when the boiler’s sensors lose track of the flame while it is trying to heat your home, causing the system to shut down as a safety precaution. The most common reasons are a worn-out component that detects the fire, a temporary drop in gas pressure, or a blockage within the boiler's internal burner or exhaust system.
This fault can be more frequent during extreme cold spells when high gas demand in the local area causes pressure fluctuations or when internal components are working at their maximum capacity.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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Gas Safe Register →Worcester Bosch models that show the 2927 B fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Worcester Bosch 2927 B 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