Low Warning
5Y on Ideal Maximiser SE

Your boiler’s control panel has become locked or entered a restricted mode, preventing you from changing any settings or operations.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Monitor it

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

Control panel locked.

What causes this fault?

This issue occurs when the boiler's internal software triggers a security lock on the control buttons, often due to a specific sequence of accidental presses or a glitch in the programming. In some cases, it can be caused by a communication error between the main circuit board and the display panel, effectively freezing the interface. Usually, it is a safety feature intended to prevent settings from being tampered with rather than a mechanical failure.

DIY fix possible

Locate the 'Mode' or 'Reset' knob on the front panel.Turn the dial to the 'Reset' position and hold it there for approximately 5 seconds.Return the dial to your desired setting (either Heating and Hot Water or Hot Water only) to see if the display clears.

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