Low
20 on Viessmann Vitodens 200-W B2HA-49

The boiler's sensor that measures the temperature of the water leaving it for the heating system has a fault, so the boiler is working from estimated readings instead, which usually still keeps your home heated but should be checked by an engineer soon.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Monitor it

This is a minor fault. Keep an eye on it and mention it at your next annual boiler service. Reset the boiler and see if it clears.

What the manual says

Manufacturer manual

Regulates without flow temperature sensor (low loss header). Cause: Short circuit, system flow temperature sensor

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 fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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Related fault codes

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All 82 fault codes on the Vitodens 200-W B2HA-49

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

4C9A9b9C9E9F10181928303838:≠0404448505890919293949899A3A4A7b0b1b5b7b8bAbbbCbdbEbFC1C2C3C4CdCFd6d7d8dAdbdCdddEdFE0E1E2E3E4E5E6E7E8EAEbECEdEEEFF0F1F2F3F6F8F9FAFCFdFEFF

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