BoilerFaultCodesTechnical description
UV sensor defective or dirty oil valve defective fault – ignition transformer badly regulated burner, oil fuel not present
What causes this fault?
This fault happens when the boiler's internal computer can no longer detect a flame, causing it to shut down for safety. The root cause is typically a dirty light sensor that cannot 'see' the fire, or a mechanical failure in the parts that deliver the oil and spark needed to create the flame.
This issue is more frequent during the first cold snap of autumn when settled debris in the fuel tank or a worn nozzle can prevent the burner from firing up after being idle all summer.
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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