BoilerFaultCodesWhat the manual says
Manufacturer manualTemperature difference between supply and return exceeding limit
From this model's manual
Verified against the Worcester Bosch/Worcester Bosch Greenstar Si Compact Erp installation & service manual.
DIY fix possible
Check that your radiators are getting warm and bleed any that have trapped air inside them.Verify that all radiator valves (both manual and thermostatic) are fully open to allow good water flow.Check that your system pressure is correct, typically between 1.0 and 1.5 bar when the boiler is cold.
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Related fault codes
All 52 fault codes on the Greenstar 25Si Compact ErP
Seeing a different code? Every code this model can display, in one place.