Low
UF on Ideal Logic Combi C24 C30 C35

Your boiler is currently set to a professional test mode for servicing and is not in its normal operating state.

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.

What the manual says

Manufacturer manual

Fault history mode diagnostic code

From this model's manual
Verified against the Ideal Logic Combi C24 C30 C35 installation & service manual.
Plain-English guidance below. Severity, DIY steps, costs and parts are our interpretation to help you act, not text from the manual.

What causes this fault?

This code appears when the boiler has been manually put into a high-performance test mode by a heating engineer during a service or inspection. It occurs because the boiler is bypasssing its normal temperature controls to run the fan at maximum speed for flue gas analysis. It is not a mechanical failure but rather a status indicator that the unit is being tested.

DIY fix possible

Locate the 'Mode' or 'Reset' knob/button on the front panel.Turn the selector knob away from the 'Service' or 'Spanner' icon back to 'Auto' or 'On'.Press the 'Reset' button once if the code persists after changing the mode.

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