BoilerFaultCodesTechnical description
Final fault, e.g.: water pressure switch, condense pressure switch, fan/flue problem, limit thermostat
What causes this fault?
This fault occurs when the boiler's safety sensors detect that the system cannot safely move air or water through the unit. It is most commonly caused by a mechanical failure in the fan or a blockage in the flue and condensate drainage system that prevents the boiler from 'breathing' correctly. In some cases, it can also be triggered if the unit overheats due to a lack of water circulation.
This fault is more frequent during periods of extreme cold, as the external condensate drainage pipe can freeze and cause a backup into the boiler.
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.