BoilerFaultCodesYour boiler has likely overheated, causing it to shut down to prevent damage.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: GO TO FRAME 76
What causes this fault?
This fault occurs when the water inside the boiler gets too hot, causing a safety sensor to shut the system down to prevent internal damage. The most common reasons are a lack of water flow caused by a failing pump or a blockage in the pipework that stops heat from leaving the boiler.
This issue often appears when the heating is turned back on for the first time in autumn, as internal parts like the pump can seize up after being idle over the summer.
DIY fix possible
Check that all radiator valves are fully openEnsure the system water pressure is between 1 and 1.5 barPress the 'Reset' button on the boiler control panel after the unit has cooled down
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 L9 — no call-out fees, no surprises.
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Ideal Elise H 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.
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