BoilerFaultCodesYour boiler has detected an issue with the sensor that monitors the drainage of condensation water, which may prevent the unit from running safely.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Appears if a problem exists with the condense sensor.
What causes this fault?
This fault occurs when the boiler's safety sensor detects that the acidic water, known as condensate, is not draining away correctly. The most common reason is a blockage in the internal condensate trap or a buildup of debris around the sensor itself, which triggers the system to stop as a safety precaution. In some cases, the sensor may have failed electronically or the wiring connecting it to the main control board has been damaged.
This fault is more common during extreme cold snaps, as the external portion of the condensate pipe can freeze, causing water to back up into the boiler.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
Find a Gas Safe engineer
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