What does the Viessmann A3 fault code mean?

The boiler has stopped its setup check because a sensor in the flue (the pipe that carries exhaust gases outside) isn't fitted in the right place, so a Gas Safe engineer needs to correct it before the boiler can run properly.

How much does it cost to fix Viessmann error code A3?

Typical repair cost for the Viessmann A3 fault is £80-180 including labour.

Viessmann A3 Fault Code: What It Means & How to Fix It

What the manual says

Manufacturer manual

Displayed when the flue gas temperature sensor is positioned incorrectly; commissioning is cancelled (referenced in the manual as fault message A3, see page 93)

From this model's manual

Verified against the Viessmann/Viessmann Vitodens 200 W B2ha 49 60 5817254 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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Related fault codes

A1View →F4View →

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

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

4C 9A 9b 9C 9E 9F 10 18 19 20 28 30 38 38:≠0 40 44 48 50 58 90 91 92 93 94 98 99 A4 A7 b0 b1 b5 b7 b8 bA bb bC bd bE bF C1 C2 C3 C4 Cd CF d6 d7 d8 dA db dC dd dE dF E0 E1 E2 E3 E4 E5 E6 E7 E8 EA Eb EC Ed EE EF F0 F1 F2 F3 F6 F8 F9 FA FC Fd FE FF

The boiler has stopped its setup check because a sensor in the flue (the pipe that carries exhaust gases outside) isn't fitted in the right place, so a Gas Safe engineer needs to correct it before the boiler can run properly.

What the manual says

Engineer required

Avoid the next call-out bill

Related fault codes

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

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