212 High

Worcester Bosch 212 Fault Code

The Worcester Bosch 212 fault code means: your boiler is overheating because the water inside is heating up faster than it can be moved around the system.. It appears on 16 Worcester Bosch models in our database.

Call an engineer soon

Book a Gas Safe engineer within 24 to 48 hours. Your boiler may be unsafe or could break down completely if left.

Technical description: The temperature recorded by the flow temperature sensor or the safety sensor is rising too quickly

What causes the Worcester Bosch 212 fault?

This fault occurs when the heat inside the boiler cannot be carried away quickly enough, causing the internal temperature to spike dangerously fast. The most common reasons are a failed pump that isn't pushing water through the pipes or a blockage, such as sludge or limescale, that is restricting the flow. Essentially, the boiler is generating heat but has nowhere to send it, so it shuts down to prevent damage.

This issue often appears at the start of autumn when the heating is turned back on after a long summer break, as internal pump components can seize up during periods of inactivity.

Typical repair cost £120-£350 (including labour)

DIY fix possible

Check that all radiator valves are fully openEnsure the boiler pressure is between 1 and 1.5 bar on the pressure gaugeCheck if the pump is running or if there are any obvious signs of a leak

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Worcester Bosch models that show the 212 fault code

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

Source

Worcester Bosch 212 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