BoilerFaultCodesTechnical description
Condensate pipe blockage / Frozen condensate (appliance makes a gurgling noise prior to locking out)
What causes this fault?
This fault occurs when the boiler's sensors detect a blockage that prevents exhaust fumes from leaving the flue or waste water from exiting the condensate pipe. The most common reason is a buildup of debris in the internal trap or an external pipe blockage, causing the system to shut down for your safety. In some cases, a faulty sensor or ignition component may also be incorrectly reporting a blockage.
This fault is significantly more common during freezing winter temperatures, as the external condensate pipe can freeze and cause water to back up 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.