BoilerFaultCodesTechnical description
Fault: Condensate or smoke
What causes this fault?
This fault occurs when the boiler's internal sensors detect a backup of liquid or exhaust gases that cannot escape the system safely. The most common reason is a blockage in the condensate trap or a failure in the external drainage pipe, which causes water to fill up inside the heat exchanger. In some cases, it can also be triggered if the flue becomes obstructed or if the internal seals have perished, allowing smoke to recirculate.
This fault is significantly more common during freezing winter temperatures, as the external condensate pipe can freeze, causing liquid 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.