Your boiler is unable to control the gas flow properly because of a communication fault between its brain and the gas valve.
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 modulator connection is broken – could be due to an internal failure.
What causes this fault?
This fault occurs when the boiler's main control board loses the ability to send electrical signals to the gas valve. The most common reason is that the wiring connecting these two components has become loose or damaged, or the internal coil within the gas valve itself has failed. Because the boiler can no longer safely regulate the amount of gas entering the burner, it shuts down for safety.
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 E11 — 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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