High
b5 on Viessmann Vitodens 200-W B2HA-60

Your boiler has detected a problem inside its own control system, so it may have stopped working until it is checked by a heating engineer.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Call an engineer soon

Book a Gas Safe engineer within 24 to 48 hours. Your boiler may be unsafe or could break down completely if left.

What the manual says

Manufacturer manual

Internal fault

From this model's manual
Verified against the Viessmann/Viessmann Vitodens 200 W B2ha 49 60 5817254 installation & service manual.
Plain-English guidance below. Severity, DIY steps, costs and parts are our interpretation to help you act, not text from the 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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Related fault codes

F.22View →F.75View →b1View →

All 82 fault codes on the Vitodens 200-W B2HA-60

Seeing a different code? Every code this model can display, in one place.

4C9A9b9C9E9F1018192028303838:≠0404448505890919293949899A3A4A7b0b1b7b8bAbbbCbdbEbFC1C2C3C4CdCFd6d7d8dAdbdCdddEdFE0E1E2E3E4E5E6E7E8EAEbECEdEEEFF0F1F2F3F6F8F9FAFCFdFEFF

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