BoilerFaultCodesYour boiler is not actually broken; it is currently in a manual service mode used by engineers to test the system or displays a history of recent issues.
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 Mode / Sequence indicator following the last 3 faults
What causes this fault?
This code appears when the boiler has been manually put into a specialized mode for testing or when the system is displaying a history of its most recent operations. It is physically triggered by an engineer interacting with the control buttons to check how the boiler is firing or to diagnose previous issues. Because this is a manual override state rather than a mechanical failure, it does not indicate that any internal parts have broken.
DIY fix possible
Check if the function knob is set to 'Reset' or a specific service position.Turn the selector knob back to the 'on' or 'standby' position.Press the reset button briefly to return the boiler to normal operation mode.
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 SL — no call-out fees, no surprises.
Affiliate links — we may earn a commission at no extra cost to you.
Ideal Logic Combi ESP1 is discontinued — time for a new one?
Parts for discontinued models can be hard to find and expensive. A new A-rated boiler could save you money on both repairs and energy bills.
Affiliate links — we may earn a commission at no extra cost to you.