BoilerFaultCodesYour boiler's main internal computer has developed a serious fault and is no longer able to manage the heating process safely.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Control failed Control has failed Replace control
What causes this fault?
This fault occurs when the boiler's internal computer chips or electrical circuits suffer a critical hardware failure. The most common reasons are simple component fatigue due to the age of the unit or damage caused by an unexpected electrical power surge.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
Find a Gas Safe engineer
Search the official register for a qualified engineer in your area.
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A boiler cover plan would cover faults like c — no call-out fees, no surprises.
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Potterton Envoy is discontinued — time for a new one?
Parts for discontinued models can be hard to find and expensive. A new A-rated boiler could save you money on both repairs and energy bills.
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