BoilerFaultCodesYour boiler's computer brain has encountered a communication error or internal failure and cannot safely operate.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Internal control unit error
What causes this fault?
This fault occurs when the boiler's main control board suffers an internal electronic failure or loses the ability to communicate with its own sensors. It is often caused by damaged wiring or a degraded circuit board that can no longer process the data needed to run the boiler safely.
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.
Gas Safe Register →Protect yourself from future repair bills
A boiler cover plan would cover faults like E17 — no call-out fees, no surprises.
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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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