BoilerFaultCodesYour boiler has shut down completely because a safety sensor has detected an internal fault that requires a professional inspection.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: The safety devices have been activated (lockout)
What causes this fault?
This fault occurs when the boiler’s safety circuit detects an internal error or overheating, causing it to shut down to prevent damage. The most common reason is a faulty safety thermostat or a breakdown in the communication between the sensors and the main control board. It can also be triggered by damaged wiring preventing the boiler from confirming that all safety systems are functioning 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.
Gas Safe Register →Protect yourself from future repair bills
A boiler cover plan would cover faults like E29 — 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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