BoilerFaultCodesTechnical description
Ignition failure/not flame sensed, condense sensor activated
What causes this fault?
This fault occurs when the boiler tries to light but fails to detect a flame, causing the system to shut down for safety. The most common cause is a blockage in the condensation pipe or a build-up of debris in the trap, but it can also be triggered by worn ignition parts or an interrupted gas supply.
This fault is more common during freezing winter temperatures, as the external condensate pipe can freeze and cause a backup that prevents the boiler from firing.
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.
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