BoilerFaultCodesYour boiler is simply displaying a reminder that its annual service is due soon or is now overdue.
This is a minor fault. Keep an eye on it and mention it at your next annual boiler service. Reset the boiler and see if it clears.
Technical description: Service interval expired
What causes this fault?
This code appears because a service timer has been programmed into the boiler's internal computer by a previous engineer. It is triggered once a set period of time—usually twelve months—has passed since the last professional maintenance visit. It is not a hardware failure, but rather an automated prompt to ensure the appliance remains safe and efficient.
This code often appears in autumn as homeowners turn their heating back on and realise a year has passed since their last pre-winter check.
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 SE — no call-out fees, no surprises.
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