i12 Low

Worcester Bosch i12 Fault Code

Also written as I12 — same fault.

The Worcester Bosch i12 fault code means: your boiler is simply displaying the current target temperature setting for your hot water, rather than indicating a fault.. It appears on 1 Worcester Bosch model in our database.

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: DHW temperature set point - This is the thermal store temperature set point, selected via the Hot Water control knob on the fascia, (rounded to 0.5°C units).

DIY fix possible

Recognise that this is an information message rather than an error codeRotate the hot water control dial on the front panel to return the display to normal modeNo further action is required as the boiler is functioning correctly

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Worcester Bosch models that show the i12 fault code

Click a model for the full fault code list and model-specific repair notes.

Source

Worcester Bosch i12 fault code information on this page is sourced and cross-checked against the official Worcester Bosch service / installation manuals for each affected model.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026