Medium
EF 349 on Worcester Bosch Junior 28i

Your boiler is struggling to move water around the system properly, causing it to throttle its power back to prevent overheating.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

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This fault should be looked at by a Gas Safe engineer within the next week or two. It may get worse if left.

Technical description

Central heating boil detected – boiler operating at minimum burner load with temperature difference greater than 18°C between Flow & Return.

DIY fix possible

Check that all radiator valves are fully openEnsure the boiler pressure gauge is between 1.0 and 1.5 barBleed your radiators to remove any trapped air

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