BoilerFaultCodesWorcester Bosch FAIL POINT J Fault Code
Also written as FAILPOINTJ — same fault.
The Worcester Bosch FAIL POINT J fault code means: your boiler has detected a problem with how air and waste gases are moving through the system, causing it to shut down for safety.. It appears on 4 Worcester Bosch models in our database.
Technical description: Air Pressure Fault (fan, air pressure switch, flue, or venturi).
What causes the Worcester Bosch FAIL POINT J fault?
This fault occurs when the boiler's internal safety sensors detect that the fan isn't moving enough air or that the exhaust gases aren't leaving the building correctly. The most common reason is a buildup of dirt in the small tubes known as the venturi, or a mechanical failure in the fan or air pressure switch. Because the boiler cannot guarantee that harmful fumes are being safely removed, it shuts down immediately as a safety precaution.
This fault is more common during periods of high winds, which can cause pressure fluctuations in the flue that interfere with the air pressure switch readings.
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 FAIL POINT J fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Worcester Bosch FAIL POINT J 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