High
348 EE on Worcester Bosch Greenstar CDi Compact

Your boiler has detected that the water inside the system is getting much hotter than it should be, so it has shut down to prevent damage or overheating.

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

HW: supply temperature too hot

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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