BoilerFaultCodesChaffoteaux BUBNEB STAYS ON Fault Code
Also written as BUBNEBSTAYSON — same fault.
The Chaffoteaux BUBNEB STAYS ON fault code means: your boiler is failing to ignite properly because debris or trapped air is interfering with the gas or water flow, meaning your heating and hot water will not work.. It appears on 1 Chaffoteaux model in our database.
Technical description: I) Air in pipework; II) Gas valve stays open; III) Venturi blocked; IV) Dirt on gas valve facing; V) Loose jumper on house stop cock tap; VI) Dirt foreign matter is water section; VII) Slow ignition device stuck
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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Chaffoteaux models that show the BUBNEB STAYS ON fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Chaffoteaux BUBNEB STAYS ON fault code information on this page is sourced and cross-checked against the official Chaffoteaux service / installation manuals for each affected model.
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 7 July 2026