High
D1 241 on Worcester Bosch Greenstar 12i System

Your boiler has lost the signal from the sensor that monitors the temperature of the water returning from your radiators, so it has stopped working to prevent damage.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

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

Return sensor error - Sensor disconnected or damaged (the boiler will block for 300 seconds before this condition).

Engineer required

This is a high severity fault. Stop using the boiler and call a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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Related fault codes

D1 240View →

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