Medium
d7 on Viessmann Vitodens 200-W B2HB-35

Your boiler has detected a problem with one of its external connections, which may affect how it responds to outside controls, so it's worth having a qualified engineer take a look soon.

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 DE2 at EA1 extension reports a fault.

From this model's manual
Verified against the Viessmann/Viessmann Vitodens 200 W B2hb B2kb 5792013 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

d6View →d8View →

All 89 fault codes on the Vitodens 200-W B2HB-35

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

9A9b9C9E9F10181920283038505158597071737475768080/EE8181/EE8282/EE838485909192939495969899A3A7A9B0b1b5b7B8bFC1C2C3C4C5CdCFd3d4d5d6d8E0E1E2E3E4E5E7E8E9EAEbECEdEEEFF0F1F2F3F8F9FAFbFCFdFEFF

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