BoilerFaultCodesYour boiler has detected a problem with the internal part that controls the gas supply, meaning it cannot ignite to provide heating or hot water.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Gas valve faulty or not connected
What causes this fault?
This fault occurs when the boiler's control center is unable to communicate with or operate the gas valve effectively. The most common reason is an electrical failure within the valve itself or a loose connection in the wiring harness that prevents gas from entering the burner. In some cases, the main circuit board may be failing to send the correct signal to open the valve.
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 E03 — 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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