BoilerFaultCodesIdeal 9F Fault Code
The Ideal 9F fault code means: your boiler's internal computer is having trouble measuring its own temperature, which prevents it from operating safely.. It appears on 1 Ideal model in our database.
Technical description: Failure regarding to control panel reference temperature.
What causes the Ideal 9F fault?
This fault occurs when the boiler's main control board loses the ability to calibrate itself against its own internal reference temperature. It is usually caused by a physical failure of the electronic components on the circuit board or a communication error within the control panel assembly. Because the boiler can no longer verify it is reading temperatures accurately, it shuts down as a safety precaution.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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Ideal models that show the 9F fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Ideal 9F fault code information on this page is sourced and cross-checked against the official Ideal service / installation manuals for each affected model.
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 7 July 2026