Low
2F:2 on Viessmann Vitodens 100-W / 200-W

Your boiler is currently running an automated process to clear air out of the system after it was recently refilled or serviced.

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.

Technical description

Filling program active

DIY fix possible

Wait 20 minutes for the automated program to finish.If the code persists, restart the boiler using the power switch.Ensure your system pressure is set correctly between 1.0 and 1.5 bar.

Find a Gas Safe engineer
Search the official register →

Related fault codes

2F:0View →2F:1View →

Related guides you might find useful

Is boiler cover worth it?

Break-even maths on monthly cover.

Read →

When to replace your boiler

7 signs repair isn't worth it anymore.

Read →

New boiler cost 2026

Realistic UK prices for a swap.

Read →