H29 Low

Worcester Bosch H29 Fault Code

The Worcester Bosch H29 fault code means: your boiler is struggling to communicate with a weather sensor outside your home, so it is temporarily ignoring the outdoor temperature readings to keep your heating running.. It appears on 2 Worcester Bosch models 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: Outdoor sensor defect (available when accessory outdoor sensor is connected)
Typical repair cost £120-200 (including labour)

Engineer required

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

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Worcester Bosch models that show the H29 fault code

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

Source

Worcester Bosch H29 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