BoilerFaultCodesYour boiler has failed to correctly detect its own flame during start-up, likely due to a minor sensor reading inconsistency.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Ion base value differs from the previous value – try resetting the boiler
What causes this fault?
This fault occurs when the boiler's internal sensor detects a change in the electrical signal produced by the flame compared to its last successful start-up. The most common reason is a buildup of carbon or moisture on the sensing probe, which prevents it from reading the flame correctly. It can also be caused by a slight degradation in the ignition cable or a worn burner seal allowing air to interfere with the reading.
DIY fix possible
Locate the Power/Reset button on the front control panelPress and hold the Reset button for 2-3 secondsWait up to 5 minutes for the boiler to complete its restart sequence
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A boiler cover plan would cover faults like 12-68 — no call-out fees, no surprises.
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Could it be time for a new boiler?
If repair costs are adding up, a new energy-efficient boiler could be the smarter long-term choice.
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