Low Service
dU on Ideal Logic Combi C24 C30 C35

Your boiler is not broken; it is simply in a special service mode used by engineers when they are preparing to replace internal parts.

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

To move the diverter valve to mid-position for replacement

What causes this fault?

This code appears when someone has manually activated the diverter valve service function, usually by pressing a specific combination of buttons. It is a programmed setting that moves internal components into a neutral position to allow an engineer to safely drain the unit and replace parts. It is not caused by a mechanical failure but by the boiler being placed into a pre-service state.

DIY fix possible

Turn the mains power to the boiler offWait 30 secondsTurn the power back on to reset the boiler to normal operation

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