CD11 Low

Warmflow CD11 Fault Code

The Warmflow CD11 fault code means: your boiler is displaying a code indicating that the mandatory safety and performance paperwork required after its initial installation or servicing has not been properly registered or finalised.. It appears on 1 Warmflow 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: OFTEC form for commissioning
Typical repair cost £0-80 (including labour)

Engineer required

This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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Warmflow models that show the CD11 fault code

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

Source

Warmflow CD11 fault code information on this page is sourced and cross-checked against the official Warmflow service / installation manuals for each affected model.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 7 July 2026