BoilerFaultCodesTechnical description
Appears if the condense trap/pipe has become blocked.
What causes this fault?
This fault occurs when the boiler detects that waste water, known as condensate, cannot flow away through the drainage pipe. The most common cause is a physical blockage in the internal trap or the external pipework, which triggers a safety sensor to prevent water from backing up into the boiler's combustion chamber. If the water cannot escape, the boiler will shut down immediately to protect its internal electrical components from water damage.
This fault is extremely common during freezing winter temperatures, as the external portion of the condensate pipe can freeze over and become completely blocked with ice.
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.