BoilerFaultCodesYour boiler has likely detected a persistent internal fault or an ignition failure and needs to be reset manually to try and clear the error.
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 77
What causes this fault?
This fault occurs when the boiler fails to light or detect a flame after several attempts, leading the system to shut down for safety. The most common reasons are a lack of gas reaching the burner, a worn-out ignition spark, or a sensor that can no longer detect the flame correctly. It essentially means the boiler’s internal computer has lost confidence that it is burning gas safely.
This fault is slightly more frequent during the first cold snap of winter when gas valves or ignition components are put under sudden high demand after sitting idle through the summer.
DIY fix possible
Locate the reset button on the boiler's control panelPress and hold the reset button for 2-3 secondsWait for the boiler to restart and monitor if the 'H n' display disappears
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 H n — 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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