BoilerFaultCodesWhat the manual says
Manufacturer manualSlow flash (normally off, flashes on) | Flashing (reset required) | Gas present and at correct pressure. Combustion CO2level. Flue condition. Ignition electrodes / harness / connections. Gas valve (coils 140-190Ω) / low voltage harness connection. Otherwise replace control board.
From this model's manual
Verified against the Worcester Bosch/Worcester Bosch Greenstar I System installation & service manual.
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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All 16 fault codes on the Greenstar 15i System
Seeing a different code? Every code this model can display, in one place.