BoilerFaultCodesTechnical description
Response from accessory module or defective condensate pump is blocking burner operation
What causes this fault?
This fault occurs when the boiler is unable to safely discharge the acidic water produced during the heating process. It is typically triggered because an external pump used to move this water has failed, or the internal electronic module that communicates with that pump has developed a fault. To prevent water from backing up and damaging the internal components, the boiler automatically shuts down as a safety precaution.
This fault is more common during freezing winter temperatures, as the external pipework can freeze and cause the pump to overflow or fail.
Engineer required
This is a high severity fault. Stop using the boiler and call a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.