Fault 50 126 Low

Worcester Bosch Fault 50 126 Fault Code

Also written as FAULT50126 — same fault.

The Worcester Bosch Fault 50 126 fault code means: your solar heating system has stopped working properly because either air is trapped in the pipes or the circulation pump has become stuck.. It appears on 1 Worcester Bosch 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: Solar pump jammed or air in system / Air in solar thermal system.

What causes the Worcester Bosch Fault 50 126 fault?

This fault occurs when the fluid in your solar heating system stops circulating correctly, meaning heat from your roof panels can't reach your water cylinder. The most common reasons are air bubbles trapped in the pipework blocking the flow or the pump itself becoming physically stuck after a period of inactivity.

This fault is frequently seen in early spring or summer when the solar system is first expected to work harder after sitting idle during the darker winter months.

Typical repair cost £120-280 (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 Fault 50 126 fault code

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

Source

Worcester Bosch Fault 50 126 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