Medium
d8 on Viessmann Vitodens 200-W B2HA-19

Your boiler has detected a problem with one of the wired connections that link it to an add-on control unit, so it may not be controlling heating or hot water as well as it should, but this is usually fixable by a heating engineer.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Book a service

This fault should be looked at by a Gas Safe engineer within the next week or two. It may get worse if left.

What the manual says

Manufacturer manual

Input DE3 fault at extension EA1

From this model's manual
Verified against the Viessmann/Viessmann Vitodens 200 W B2ha B2ka 5772909 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 fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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Related fault codes

d7View →d9View →

All 83 fault codes on the Vitodens 200-W B2HA-19

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

4C9A9b9C9E9F101819202830384044485051585990919293949899A3A7b0b1b5b7b8bAbbbCbdbEbFC1C2C3C4C5C6C7C8CdCFd6d7dAdbdCdddEdFE0E1E3E4E5E7E8EAEbECEdEEEFF0F1F2F3F8F9FAFCFdFEFF

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