What the manual says
Manufacturer manualBoiler in heating mode - Heating circuit is being heated.
From this model's manual
Verified against the Worcester Bosch/Worcester Bosch Greenstar 4000 installation & service manual, page 71.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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All 105 fault codes on the Greenstar 4000
Seeing a different code? Every code this model can display, in one place.
201202203204208214224227228232233234235237238242245249250251252253254258259262263265268269273281283284305306353357358360362363810811101010131017101810191021102210231037106510681070107110721073107410751076208529082910291429152916292029232927292829312940294629482949295029512951 V29522952 V29572957 V29612961 V29622962 V29632963 B29642964 B29652965 B29662966 B29672967 B29702970 B29712971 B29722972 V