BoilerFaultCodesViessmann 1F Fault Code
The Viessmann 1F fault code means: your boiler has stopped working because the burner isn't lighting correctly, likely due to a problem with the internal airflow or the ignition system.. It appears on 12 Viessmann models in our database.
Technical description: Burner blocked
What causes the Viessmann 1F fault?
This fault occurs when the boiler's control system detects that the burner cannot sustain a stable flame after several attempts. It is usually caused by a lack of proper airflow or an issue with the sensors that verify the flame is safe to stay on. The most common reasons are worn-out ignition components or a build-up of debris within the burner chamber that prevents a clean light-up.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
Find a Gas Safe engineer
Search the official register for a qualified engineer in your area.
Gas Safe Register →Viessmann models that show the 1F fault code
Click a model for the full fault code list and model-specific repair notes.
- A8 Repair: £120-350
- Vitodens 050-W Repair: £150-450
- Vitodens 100-W / 200-W Repair: £150-450
- Vitodens 111-W Repair: £150-450
- Vitodens 200 Repair: £150-450
- Vitodens 200-W Repair: £150-450
- Vitodens 222-W Repair: £150-450
- Vitodens 333-F Repair: £150-450
- Vitola Biferral Repair: £120-280
- Vitopend 100 Repair: £120-350
- Vitopend 111 Repair: £120-£350
- Vitorond 100 Repair: £120-350
Source
Viessmann 1F fault code information on this page is sourced and cross-checked against the official Viessmann service / installation manuals for each affected model.
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026