Your boiler is simply confused because the reset button was held down for too long or pressed when it wasn't needed.
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: Reset button pressed by mistake.
What causes this fault?
This fault occurs when the boiler's internal computer receives a signal from the reset button for longer than expected, usually because the button was held down for more than 30 seconds. It can also happen if the button is pressed too many times in a short period or if it gets physically stuck in the control panel. Essentially, the boiler enters a confused state as a safety precaution because it cannot tell if you are trying to reset it or if there is a mechanical hardware failure.
DIY fix possible
Press the reset button again firmly once and release it immediately.Turn the power to the boiler off at the fused spur switch, wait 30 seconds, and turn it back on.If the code persists, wait 30 seconds for the display to clear itself naturally.
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