Your boiler has detected a potential blockage or issue with the gas supply or internal gas valve, causing it to shut down for safety.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Fault: Check gas route. A fault message is activated. Check the gas route.
What causes this fault?
This fault occurs when the boiler’s internal sensors detect that gas is not flowing correctly through the main valve or the internal pipework. It is usually triggered by a mechanical failure in the gas valve itself or a communication error from the main control board. In some cases, a physical blockage or debris inside the boiler's gas route prevents the system from safely igniting.
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 S.63 — 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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