BoilerFaultCodesYour boiler has detected an electrical safety issue where the power supply is not properly grounded or the internal control board has failed.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Mains supply not correctly earthed. Control unit or earth fault
What causes this fault?
This fault occurs when the boiler's internal computer detects that the electrical supply is missing a secure connection to the ground. The most common reason is a loose or corroded wire within the boiler itself, or a critical failure of the main control board which prevents it from sensing the electricity correctly.
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 e3 — 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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