Worcester Bosch h13/H13 Fault Code
Also written as H13H13 — same fault.
The Worcester Bosch h13/H13 fault code means: your boiler is simply reminding you that its annual service is now due to keep it running safely and efficiently.. It appears on 2 Worcester Bosch models in our database.
Technical description: Service reminder reset notification / service is now due
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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Gas Safe Register →Worcester Bosch models that show the h13/H13 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Worcester Bosch h13/H13 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