Medium
EF 349 on Worcester Bosch Danesmoor

Your boiler has slowed down because it is struggling to circulate water quickly enough through your radiators.

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 system pressure is between 1 and 1.5 barBleed your radiators to remove trapped air

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